You may assume that children have nightmares about monsters under the bed, while adults dream about stressful events like deadlines. But is there any scientific evidence showing that dreams change as we age?

Although there are plausible mechanisms for how aging could cause dreams to change over time, very little research has explored the topic.

"Dreaming depends on neural systems involved in imagination, memory and emotion, all of which develop and reorganize with age," Dr. Giulio Bernardi, head of the Sleep, Plasticity, and Conscious Experience (SPACE) research group at the IMT School for Advanced Studies Lucca in Italy, told Live Science. However, "surprisingly few studies have systematically examined how dreams change across the lifespan."

The studies that have investigated this idea have shown that people tend to report their dreams differently at various stages of their lives. While younger dreamers tend to see and feel more vividly, older people recall more complicated and less-emotional situations.

One of the simplest, and perhaps most common, explanations for the way our dreams adapt and evolve is called the "continuity hypothesis," first put forward in 1971.

According to that theory, our dreams tend to mirror what we're experiencing in our waking lives — if we're lounging on vacation, we may see sun and sand when we fall asleep, but if we're anxious about work, we may be transported to the office. But ultimately, the parallels between sleep and reality reveal very little about why our dreams might change as we grow up.

"Changes in dreaming across life reflect the complex interaction between brain development, sleep architecture, and cognitive-emotional maturation," Bernardi said. Everything from memory to sleep quality can influence how we experience both dreams and their aftermath: "These factors determine not only how vividly dreams are produced during sleep but also how likely they are to be remembered upon awakening."

How dreams change with age

The foundational research on how children dream was done by sleep researcher David Foulkes from the 1970s to the 1990s. According to his research, young people's dreams tend to be relatively straightforward — they feature animals, static objects and simple interactions. (However, research on children's dreams involves complications because the results depend on each child's ability to understand what dreams are and how to relay them to others.)

In adolescence, dreams tend to become more frequent and more vivid than they were in childhood, reflecting the many changes we're experiencing in our waking lives. While younger adolescents report dreaming about falling, being chased, and confronting monsters or animals, older teens reexperience the stresses of school and new relationships.

In adult life, dreams usually become a bit more mundane. One study found that adults and older adults dream about arriving somewhere late and "trying again and again to do something" more often than other age groups. Odd dreams and nightmares still occur, but the aggression of adolescence starts to fade and the complexity of dreams starts to reflect our waking life even more.

Studies show that in old age, people don't tend to report having as many dreams. Many also experience "white dreams," in which they recall having a dream but aren't quite sure what happened during it. While some of this can be explained by the lower quality of sleep that older adults tend to experience, much of this change — as is the case with dreams at all ages — has to do with the ability to accurately and descriptively remember what we saw in our sleep.

"Dreaming is defined as subjective experiences that occur during sleep," Michael Schredl, head of the sleep laboratory at the Central Institute of Mental Health in Germany, told Live Science. "What we get is only the dream or dream report, the recollection of those experiences that occurred during sleep."

At the end of life, and during the dying process, people often report seeing departed loved ones and recall visions of packing and preparing to go on a trip in their dreams. Studies of hospice patients have found that these dreams are often comforting and put people at ease, mirroring the reflection that often occurs at the end of life.

Sleep quiz: How much do you know about sleep and dreams?

We dream every night, but we often can't remember those dreams. Some mornings, we recall vivid details, and other days, we piece together hazy outlines. But what about color? Do most people dream in color or in black and white?

Some people may be surprised to learn that this has proved a divisive question. Modern research has indicated that television and films have a lot to do with how we experience dreaming and what we can remember when we wake up.

"Since we're used to colored media, we think dreams must be kind of like watching a movie or watching something on YouTube," Eric Schwitzgebel, a professor of philosophy at the University of California, Riverside, told Live Science. "Those things are colored, so we tend to assume that dreams are too."

But that hasn't always been the case. Up until the 1960s, researchers thought people largely dreamed in black and white, and surveys have backed this hypothesis. A small study of 277 people published in 1942 found that 70.7% of the college sophomores surveyed rarely or never saw colors in their dreams. Nearly 60 years later, Schwitzgebel asked a group of 124 college students the same questions — and the results had shifted drastically. In the more recent survey, less than 20% of the students surveyed reported rarely or never seeing colors in their dreams.

Other recent studies have produced similar results. Researchers have discovered a pattern: People born before the advent of color television and movies were much more likely to report having monochromatic dreams than people born after. This suggests that the way we interpret our dreams is affected by the types of media we consume.

Entertainment isn't the only factor. Much of what we take away from our nightly dreams has to do with how accurately we remember them and which details stick with us the most.

"Dreams are defined as subjective experiences during sleep, and the only way we can get to them is if the person is remembering them after waking up," Michael Schredl, head of the sleep laboratory at the Central Institute of Mental Health in Germany, told Live Science. "The main problem is, 'how good are you at recalling?'"

Just as in waking life, the colors of objects can be quite forgettable if they match what we expect to see. For example, a yellow banana in a dream probably wouldn't leave a lasting impression.

"You don't think about it, and it's difficult to remember," Schredl said. But if a neon-pink banana appears in a dream, it might make more of an impact.

What's more, if a particular color is significant to a person, they may be more likely to remember it.

"If the color has a specific meaning for the person in her or his waking life, then it might be that the color might point to something," Schredl said. "It's not about the color itself but how the color is affecting the person."

But Schwitzgebel argues that the question of whether we dream in black and white or color could be a bit misguided in the first place. When we imagine a scene in which the colors aren't important, our mental image may not be in black and white or in color; it may just be a fuzzy, "indeterminate" image. Or perhaps what we remember in the morning is slightly different from the mental image we had while dreaming, informed more by assumptions than memory. Dreams might be less of a visual, movie-like experience than we tend to assume, he said. Rather, it's possible our media consumption affects how we remember our dreams.

"A lot of people can't really quite get their minds around what it would mean for a dream experience to be neither colored nor black and white," he said.

Sleep quiz: How much do you know about sleep and dreams?

You look up from your phone screen and suddenly realize you weren't thinking about anything. It's not a lapse in memory or a daydream; it's literally a moment when you're not thinking of anything at all.

Neuroscientists have a term for it — mind blanking — which they define as a brief, waking state when conscious thought simply stops.

Scientists used to think our waking minds were always generating thoughts, but recent research shows that's not the case. Mind blanking is now recognized as a distinct conscious state associated with changes in arousal, which in neuroscience refers to alertness and responsiveness to stimuli. Studying this curious state could shed light on how consciousness works, some researchers think.

"For some, it's kind of a blip in the mind, and suddenly there's nothing," Thomas Andrillon, a neuroscience researcher at the French National Institute of Health and Medical Research and the Paris Brain Institute, told Live Science. "But not with that feeling, 'There was something that I forgot.'"

Often, people are unaware of the lapse until they are prompted to answer "What were you just thinking about?"

"When we interrupt them randomly," Andrillon continued, "it's clear it's more frequent than what people realize." Although the frequency of this phenomenon varies among individuals, various studies suggest about 5% to 20% of a person's waking hours may be spent in this state.

Related: Super-detailed map of brain cells that keep us awake could improve our understanding of consciousness

Investigations of 'mind blanking'

In a review published in the July issue of the journal Trends in Cognitive Sciences, Andrillon and Athena Demertzi, a neuroscience researcher at the GIGA Institute-CRC Human Imaging Center at the University of Liège in Belgium, collaborated to compile results of recent studies performed in each of their labs, respectively.

Andrillon and his team used electroencephalography (EEG) — which involves placing electrodes on participants' heads — to measure brain activity while people experienced lapses in attention, such as mind wandering or mind blanking. Mind wandering occurs when people's thoughts drift to tasks or ideas unrelated to the one at hand, while mind blanking involves the absence of all thought.

Because most of the presented numbers required a response, people often pressed the button by mistake when they saw a 3 onscreen. The researchers paused the task once a minute to ask what the participants were thinking, finding that they were either focused on the task, their mind was wandering, or they were experiencing a "mind blank."

Participants pressed the button more quickly when their minds were wandering, whereas their responses slowed noticeably during mind blanking, suggesting these two mental states are distinct.

Brain activity told a similar story. The EEG data showed that the participants' brain activity tended to slow down slightly more when their minds were blank than when they were wandering, compared to the baseline of their paying attention. “The connectivity changes as if the inner workings of the brain were specific, in a way, to that state," Andrillion said.

EEG data is great for tracking rapid changes in brain activity, but it can't pinpoint exactly which brain regions are involved. That's in part because it records brain waves through the skull, and the signals blur as they make their way through the brain tissue, fluid and bone. Andrillon explained it's like listening through a wall. You can tell if a group inside is noisy or quiet, but you can't tell who is talking.

The EEG results from the study suggest that during mind blanking, the brain's activity slows down globally, but the technique couldn't identify specific areas. That's where functional MRI (fMRI) came in.

Related: 'Hyper-synchronized' brain waves may explain why different psychedelics have similar effects, rat study reveals

Hypersynchronization

fMRI provides a clearer view of which regions are active and how they interact, but its tracking speed is slower because the technique tracks bloodflow, rather than directly following brain signals. fMRI is more like peeking into the room and seeing who's talking to whom, but not knowing precisely when, Andrillion said.

Demertzi, coauthor of the review, led recent fMRI research into mind blanking in her lab. As people rested in an fMRI scanner with no particular task at hand, Demertzi and her team periodically asked what they were thinking.

The results were surprising: when people reported mind blanking, their brains showed hyperconnectivity — a global, synchronized activity pattern similar to that seen in deep sleep. Typically, when we are awake and conscious, our brain regions are connected and communicating but not synchronized, as they appear to be during mind blanks.

"What we think happens in the case of mind blanking is that the brain is pushed a little bit toward the side of synchronization," Andrillon said. "That might be enough to disrupt these sweet spots of consciousness, sending our mind to blank."

Research into mind blanking is still in its early stages, but Andrillon and Demertzi noted that its similarity to brain patterns seen during deep sleep may offer an important clue as to its function. Deep sleep, also known as slow-wave sleep, coincides with important cleanup work for the brain. It clears away accumulated waste, cools the brain, conserves energy and helps reset the system after a full day of mental activity.

Andrillon and Demertzi suggested mind blanking may act as a mini-reset while we're awake. Demertzi said it's like "taking five to steam off" or "to cool your head." Early studies in Demertzi's lab suggest sleep-deprived people report more mind blanks, adding support to this idea.

Both researchers stressed that this state is likely a way for the brain to maintain itself, though "it's not ideal for performance," Andrillon said.

Andrillon believes it's possible but unlikely that there are people who have never experienced mind blanking. Detecting a mind blank can be a challenge. "It can require being interrupted," Andrillon said, "to realize, 'OK, actually, there was no content.'"

Editor's note: This story was updated on Aug. 4, 2025, to clarify that the recent publication was a review of work done separately in Andrillon's and Demertzi's respective labs.

How fast do humans think? According to a new study, it's slower than you might expect.

The peripheral nervous system — the network of nerves that deliver information between the brain and the body — takes in environmental information at over a billion bits per second, a speed comparable to a lightning-fast internet connection. But people think and process that information at just 10 bits per second, researchers report in the study.

This vast gulf hints at major unexplored questions in neuroscience and human cognition.

"That number is ridiculously small compared with any information rate we encounter in daily life," the researchers wrote in the study, published Dec. 17 in the journal Neuron. "For example, we get anxious when the speed of the home WiFi network drops below 100 megabits per second because that might compromise our enjoyment of Netflix shows. Meanwhile, even if we stay awake during the show, our brain will never extract more than 10 bits per second of that giant bitstream."

Study co-authors Jieyu Zheng and Markus Meister of Caltech determined this speed limit by calculating the number of bits required to perform a task, such as solving a Rubik's Cube or memorizing the order of a deck of cards, and dividing it by the time it took to perform each task. For record-holding memory experts who can finish those tasks in seconds, the rate at which they processed information was roughly 10 bits per second.

The study raises several questions about how and why human brains filter out all of the extra information taken in by the nervous system. A single neuron can fire fast enough to transmit information at 10 bits per second.

"That one single neuron can perform as well as a monkey," Zheng told Live Science. "You just need one neuron to encode a yes or no decision, and that is enough for you to output that behavior. So why do we need billions of neurons to do this while we still output at 10 bits per second?"

The study also proposes an explanation for why humans can't follow multiple trains of thought at once, like listening to several simultaneous conversations at a party. Evolutionary history may be responsible for this single-minded focus, the researchers proposed. The first nervous systems in early animals were only responsible for guiding an organism toward food or away from danger, so they needed to make only one decision at a time: which direction to move. More abstract thought follows similar "paths" and may have inherited the constraint of processing just one path at a time, the study authors suggested.

The team proposed that the brain operates in two simultaneous modes: an "outer brain" that takes in millions of bits of data and an "inner brain" that focuses on one small portion of that data at a time. To determine how the outer and inner brain communicate with each other, researchers will have to study individuals' brains while they perform complex tasks, such as driving a car, that require people to frequently shift their attention to different aspects of the task, Zheng said.

"How does [the inner brain] do task control?" Zheng said. "How does it choose which 10 bits per second we are paying attention to? We are really hoping that people can go deeper into this."

Arguably the most complex organ in the body, the brain is an elegant mess of cells, chemicals and electrical impulses that orchestrates our thoughts, behaviors and unconscious bodily functions.

This year, Live Science covered a slew of fascinating studies about the brain, each of which revealed new insights about how the organ ticks while also raising new questions.

Related: Master regulator of inflammation found — and it's in the brain stem

The male hormone cycle and the brain

Although not often discussed, the male hormone cycle is quite striking. Steroid hormones in the male body — including testosterone, cortisol and estradiol — decrease about 70% throughout the day and then reset overnight. This year, a brain-scan study revealed that the brain loses and regains volume in time with this daily cycle. At this point, though, it's unclear whether the hormones themselves drive the brain changes or how this cycle affects male brain function.

Your brain on cinema

Many people throw on a movie when they want to "turn off their brain" for a bit. But a recent study found that, actually, 24 different brain networks light up as you watch different types of films. By tying brain activity patterns to what was happening in a given scene, the scientists behind the study were able to construct the most accurate functional brain map to date.

Transformation of babies' brains after birth

A groundbreaking study in fetuses and newborns highlights how the activity of certain parts of the brain suddenly shift after birth. There is a huge uptick in activity in the subcortical network, which acts like a relay hub for information, and the sensorimotor network, which is responsible for processing external stimuli and coordinating movements. The researchers now want to study the same brain networks in preterm babies, to see if there's a notable difference from full-term babies.

The drive to eat

A simple circuit made of just three types of neurons may underlie our drive to eat, a study found. The brain cells work together to detect hunger-signaling hormones and ultimately set off cells that control the muscles for chewing. By messing with this circuit in lab mice, the researchers prompted the rodents to eat 12 times more food than usual and make chewing movements even when they had no food.

Pregnancy's "permanent etchings" on the brain

Throughout pregnancy, about 80% of the brain's gray matter loses volume. Some of this lost volume reappears postpartum, but much of the missing matter stays lost. A similar loss of gray-matter volume is seen during puberty, a time when the brain is "pruning" away excess connections to boost its efficiency. It may be that this change in pregnancy reflects a similar fine-tuning of brain circuitry, scientists say.

Three copies of each memory

A mouse study suggests that the brain may store at least three copies of every memory it encodes. These copies differ in when they're created, how long they last and how modifiable they are over time. Understanding when and how these different copies form could help scientists address conditions that affect memory encoding and retrieval, such as PTSD and dementia.

Conscious lab-grown brains?

Could brain organoids — miniature models of the brain grown in the lab — ever gain consciousness? Live Science posed the question to neuroscientist Kenneth Kosik, who assured us that it's not likely to happen anytime soon. However, there is still ongoing debate about what qualifies as "consciousness," he noted. And there are big questions about what could happen if human minibrains were transplanted into animals or hooked up to technologies to create so-called cyborgs.

Related: Optical illusion reveals key brain rule that governs consciousness

'Shrooms that "dissolve" sense of self

Psilocybin, the active ingredient in magic mushrooms, may cause the brain network responsible for maintaining a person's sense of self to fall out of sync. Called the default mode network, this brain circuit is most active when people are self-reflecting and not engaged in any particular task. On high-dose psilocybin, the network's activity temporarily changed, with some of the effects lasting a few weeks.

Origin of psychosis

A brain-scan study could help confirm a theory about why people experience psychosis, or sudden breaks from reality. Using artificial intelligence (AI) to analyze the scans, scientists found overlapping "signatures" in the brains of people with psychosis. These signatures were either tied to a genetic condition or were from an unknown cause. The findings back a theory that, in psychosis, brain networks in charge of directing a person's attention malfunction, which leads to hallucinations and delusions.

"Universal" brain pattern in primates

Multiple primate species, including humans, share a common brain-wave pattern in the cerebral cortex, the outer surface of the brain. This universal pattern is marked by high-frequency brain waves in the upper layers of the cortex and slower waves in its deeper layers. Scientists think the interplay of fast and slow waves dictates which information remains in conscious thought at any given moment.

Flow state

Scientists revealed the key parts of the brain that switch on when someone is in a flow state — or "in the zone." The study involved scanning the brains of musicians with varying degrees of experience. It pitted two competing theories of "flow" against each other, and one theory came out on top.

Reading in a "blink"

A study found that the human brain can discern the basic structures of written language in the time it takes to blink. That suggests the brain can process written phrases about as quickly as it does visual scenes of the world around us. The study's subjects seemed to process phrases that included subjects, verbs and objects faster than they did lists of nouns. They were also quick to process when the meaning of a phrase didn't quite make sense. The findings suggest the brain isn't only detecting that words are present but also starting to parse meaning right away.

Big brains from gut bugs

A mouse study suggests that humans' remarkably big brains may have evolved partly thanks to the unique microbes in our guts. The study researchers transplanted microbes from the guts of humans and nonhuman primates into mice. The microbes from humans and big-brained primates converted food into energy for the brain more efficiently compared with the microbes from small-brained monkeys. The findings suggest that the big-brain microbes convert food into energy for the brain more efficiently, thus helping fuel the organ's growth.

Stunning new brain map

Researchers from Harvard and Google unveiled a striking map of a small sliver of the human brain. It contains roughly 57,000 neurons, 9 inches (23 centimeters) of blood vessels and 150 million synapses (the connection points between neurons). The map highlighted unique and unexpected features of the brain, including mysterious "whorls," or knots, in the outgoing wires of some neurons.

3D-printed brain tissue that actually works

In a first, scientists 3D printed functional human brain tissue. The printer itself used stem cells instead of ink, and the team then used a concoction of chemicals to spur those cells to transform into brain cells. The resulting cells could communicate and link up in networks, similar to cells in an actual brain.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

"Look for the gap!" "Move into space!" "Who's free?"

Sound familiar?

From the sidelines to the field, court or pitch, no matter the team sport, looking for relevant information in the playing environment can be as important as any other skill if you want to score… and hopefully win the game.

Think Lionel Messi, Scott Pendlebury, or Natalie Medhurst, coolly assessing all the options before making pivotal decisions.

How do these elite athletes become so great? As well as their physical attributes, their brain power is an obvious asset.

Related: Will Olympic athletes ever stop breaking records?

Cognitive power in sport

Regardless of whether an athlete is playing under-5's soccer, backyard cricket or Olympic basketball, their playing environment holds important information that must be found, interpreted and then acted on.

As the athlete becomes more experienced with repeated game play, they become used to exploring the environment and the likely outcomes for different choices — such as in soccer, deciding on a long kick or a short pass.

This is how motor (movement) and cognitive expertise develops and can increase tactical and strategic options and solutions.

Cognitive expertise refers to factors such as decision-making, attention and perception, which are essential for skilled performance.

A key part of making decisions in sport, particularly fast-paced sports, is knowing where to look to find the most useful information around you. In other words, where you should direct your attention, particularly visual attention.

Research tends to find skilled players are better at looking for and seeing the options and what's happening around them in the playing environment.

For example, skilled players tend to have a wider focus of attention (when needed) — this means they look both at an opponent and where they can move to next.

Less skilled players, on the other hand, tend to have a narrower focus of attention. They might watch only one detail (such as the ball) but not what is happening around them.

An eye-tracking activity with soccer star Cristiano Ronaldo showcases this well:

Skilled players are also often faster to make decisions compared to less skilled players; their experiences create more stored memories that help speed up their decision-making.

In essence, skilled players know what information is the most relevant to focus on and they act on it quickly.

Related: What's the heaviest weight a person can lift?

Training the brain

Many in high performance environments acknowledge that we are near our physical limit with current practices.

Despite this, many coaches and athletes focus on the physical aspects of preparation such as speed, endurance and strength.

This focus is understandable — concentrating on physical aspects might work for sports that are driven largely by factors such as physical capacity and less by specific skills.

For sports like soccer, Australian rules football, hockey and basketball however, where complex thinking skills are needed, this approach is limited.

To put it simply: being able to move quickly and powerfully is helpful. But if you're running to the wrong spot, or kicking to a teammate in a bad position (overlooking a much better option), this lack of cognitive skill can limit success.

And there is more we can do with cognitive processes as our understanding continues to grow.

New research shows the importance of brain power

A recent study from Western Sydney University looked at Australian rules football players aged 14 to 18, and the skills they need to play at higher levels.

The researchers wanted to explore how junior players look around the field and make passing decisions, and if these behaviours stay the same over time (18 months, to be exact).

They found, similar to adult athletes, there are distinct differences for visual behaviors and decision-making abilities between skilled and less skilled juniors.

The more skilled players were more accurate in their decision-making and visual search behaviours, focusing on the most relevant game play information such as free players or space to move into.

Processing information under pressure is also key to skilled performance, with research showing physical fatigue affects decision-making, often leading to errors in decisions that can be costly.

For coaches, it is particularly important to consider cognition and fatigue in training — simulating game-like pressure is useful for players to get used to the types of pressures they will experience in competition.

Adding to this picture is new research that explores the negative impact of mental fatigue on physical performance. This work showed our ability to exercise can be impaired after activities requiring long periods of thinking and mental effort, particularly when these activities are boring.

This research is unique, as it considers the impact of using the brain so much that it makes you physically tired (often, we view fatigue from the perspective of how physical fatigue effects thinking).

This may be particularly relevant for coaches of young players transitioning from the school day to training, especially if the day's lessons have been complex.

Coaches should therefore consider the amount of information they provide athletes and the complexity of the tasks and instructions.

Related: 'Muscle memories' get 'zipped and unzipped' in the brain, like computer files

Striking the right balance at training

Overall, cognitive skills, like physical attributes, are key to high performance and even play a role in identifying future potential.

Developing talent in sports is a key focus for many sports clubs but the process relies mostly on testing physical and physiological aspects.

The research conducted at Western Sydney University showed cognition could be a reliable marker of ability over time and provide some basis for prediction of talent.

If so, the methods used or similar approaches could be included in talent identification protocols.

In a first, scientists have used ultrasound waves to peer inside a person's brain. The man's brain activity was recorded as he completed tasks outside a medical facility, including playing a video game. 

To achieve this feat, researchers implanted a material into the man's skull that allowed ultrasound waves to pass into his brain. 

After entering through this "acoustically transparent" window, these waves bounced off boundaries between tissues. Some of the bouncing waves then returned to the ultrasound probe, which was connected to a scanner. The data allowed scientists to build a picture of what was going on in the man's brain, similar to how ultrasound scans can visualize a fetus in the womb. 

The team monitored changes in blood volume in the brain over time, specifically zooming in on brain regions called the posterior parietal cortex and the motor cortex. Both of these regions help to coordinate movement.

Related: Super-detailed map of brain cells that keep us awake could improve our understanding of consciousness

Assessing changes in blood volume is one way to indirectly track the activity of brain cells. That's because when neurons are more active, they require more oxygen and nutrients, which are delivered by blood vessels.

The new study built upon prior research in nonhuman primates. Now working with a person, scientists were able to use ultrasound imaging to monitor the precise neural activity unfolding in a man's brain as he conducted various tasks, such as playing a simple connect-the-dots video game and strumming a guitar. The team described their findings in a paper published May 29 in the journal Science Translational Medicine.

"Just as had been the case with nonhuman primates, the patient's ultrasound data indicated intentions — move this joystick, strum this guitar — while the actions themselves were taken," Dr. Charles Liu, co-senior study author and a neurosurgeon at the University of Southern California, said in a statement.

Related: New ultrasound device helps powerful chemo reach deadly brain cancers, human trial shows 

Functional ultrasound imaging — meaning ultrasound that tracks changes in blood volume in the brain — is considered a promising alternative to conventional brain imaging techniques, such as functional magnetic resonance imaging (fMRI). This is because it's thought to more sensitive to changes in brain activity. In addition, the resulting images have higher resolution, and the method doesn't require patients to lie still in a machine for extended periods of time in a hospital. 

As such, you could theoretically track the brain activity of patients in real-life settings. This is currently possible with ambulatory EEG, but EEG tracks electrical activity, rather than blood flow, and it does so through the skin of the head and the skull, so it's not super precise.   

Similarly, the human skull has historically been a barrier to ultrasound waves, preventing them from entering the brain. That's why, in the new study, Liu and colleagues overcame this obstacle by testing their approach in a patient who'd had some of his skull removed. This had been done to relieve pressure in his brain after a severe traumatic brain injury (TBI). 

Normally, TBI patients who undergo this procedure are given a titanium mesh or custom-built implant to replace the missing part of their skull. In this case, the team built the acoustically transparent implant. In the future, the new technique may not be limited to patients with TBI, the study authors said. 

"There are a number of interventions that require removal of a portion of the skull," Mikhail Shapiro, co-senior study author and a professor of chemical engineering and medical engineering at Caltech, said in the statement. "So, there are many patients who could potentially benefit from a cranial implant that is transparent to the acoustic signals that ultrasound uses."

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Scientists have pinpointed the brain network that's involved in stuttering, brain scans reveal. 

The work suggests that stuttering may be triggered by disruption to a specific network of brain cells, or neurons that connects three major regions of the brain. These regions — the amygdala, the putamen and the claustrum — are respectively involved in regulating emotions, controlling movements and relaying information between different areas of the brain.

The brain imaging results were described in a recent paper, published May 27 in the journal Brain. 

Knowing what causes stuttering could aid the development of new targeted treatments for the condition, Dr. Juho Joutsa, co-senior study author and a professor of neurology at the University of Turku in Finland, told Live Science. Such treatments could include the use of electrical brain stimulation, which involves placing electrodes on or inside a patient's head and delivering pulses of electricity to target areas of the brain at specific times. 

Related: Super-detailed map of brain cells that keep us awake could improve our understanding of consciousness 

Finding a new target for treatment

Stuttering is a speech disorder that affects around 1% of adults and between 5% and 10% of children. The condition causes people to involuntarily repeat or prolong certain sounds, syllables and words as they speak, as well as experience "blocks" in speech. People who stutter can therefore experience difficulty in communicating with others, which can contribute to social anxiety. 

There are two major types of stuttering: developmental stuttering, which emerges in childhood but resolves before age 18 in up to 90% of cases, and the less-common, acquired form of stuttering, which can occur after a brain injury. These injuries include those caused by a stroke, or a disease such as Parkinson's.

Stuttering is typically treated with speech therapy. However, the benefits of this treatment do not always last, and there are currently no effective drugs to treat the condition. 

Until now, scientists didn't know where in the brain stuttering originated, which limited their ability to come up with alternate treatments. 

To find answers, Joutsa and colleagues started by looking at published medical case reports from 20 people who'd started stuttering after a stroke. They compared these reports to those from nearly 170 stroke patients at Turku University Hospital in Finland who did not develop stuttering. The team found that, in those who started stuttering, the damage caused by their strokes showed up in different parts of the brain but all clustered in the same brain network. The people who didn't develop stuttering didn't show this pattern.

The team uncovered this same pattern in a separate experiment in which they used magnetic resonance imaging (MRI) to scan the brains of 20 people who had developed stuttering after a stroke. 

Related: A mysterious brain network may underlie many psychiatric disorders

To determine if this brain network might indeed be responsible for all types of stuttering, and not just those caused by brain damage, the team also imaged the brains of 20 adults with developmental stuttering. In addition to scanning participants' brains, the researchers assessed the severity of their stuttering symptoms through video-recorded conversations and a questionnaire that the participants filled out. 

They uncovered patterns in how the participants' symptom severity related to the structure of their gray matter, which includes the main bodies of neurons. People more severely impacted by their stuttering showed higher gray matter volume in the same brain network linked to stuttering after stroke. This correlation was consistent in that, the greater the volume someone showed in the network, the more severe their stuttering was. 

Taken together, these findings suggest that there is a common brain network underlying stuttering, regardless of its original trigger. 

This raises the possibility of targeting this network to treat the condition, Joutsa said. Electrical brain stimulation is already used to treat patients with various disorders, such as obsessive compulsive disorder, depression, Parkinson's disease and essential tremor. It is also currently being tested for the treatment of additional neurological conditions, such as traumatic brain injuries. 

In theory, brain stimulation may also be able to help prolong the beneficial effects of speech therapy in some patients, Catherine Theys, the study's lead author and an associate professor of psychology at the University of Canterbury in New Zealand, told Live Science. The new findings could help clinicians make more informed decisions about which treatments to select for each patient, she said. 

However, there is a "long road ahead," as it may take years for this vision to be realized, Joutsa said. 

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The first person with Neuralink's computer-linked chip implanted in the surface of their brain showed off their "telekinetic" online chess-playing skills while discussing the "life-changing" procedure for the first time in a surprise livestream. 

Noland Arbaugh, a 29-year-old with quadriplegia (or paralysis that affects the body from the neck down), volunteered to have the device implanted as part of Neuralink's ongoing trial of the technology. Until now, his identity had remained a closely guarded secret.

In the video, which was posted March 20 on X, formerly known as Twitter, Arbaugh played a game of online chess on a laptop while controlling the cursor with his thoughts. He said that controlling computers with his mind felt "like using The Force" and joked that he planned to dress as the telepathic superhero Professor X for Halloween this year.

Arbaugh described learning to use the brain chip to control a computer cursor, initially by attempting to move his hand to generate the necessary brain signals. 

"From there, I think it just became intuitive for me to start imagining the cursor moving," he said in the livestream. "Just stare somewhere at the screen and it would move where I wanted to, which was such a wild experience."

Related: New 'thought-controlled' device reads brain activity through the jugular

Neuralink is a U.S.-based company founded and owned by SpaceX mogul Elon Musk. It specializes in brain-computer interfaces (BCIs), devices that read brain activity and translate it into commands that operate a computer system. 

The Neuralink device being tested, called Telepathy, is around the size of a coin and is implanted into a small hole in the skull, which is drilled by a robot. Once inserted, the device releases electrode threads that connect to "a region of the brain that controls movement intention," Neuralink representatives wrote in a previous statement. The device then detects the brain's electrical signals and wirelessly transmits that data to an app, which ultimately translates it into computer commands that can control a keyboard and mouse.

The U.S. Food and Drug Administration cleared the device to be tested in human trials in June 2023. In January this year, Musk announced that the first device had successfully been implanted into a human patient, who we now know was Arbaugh.

The livestream was completely unexpected and is the first update from Neuralink on the company's X account since it reposted Musk's announcement in January.

Arbaugh, who said he sustained his injuries after a diving accident eight years ago, appeared to be at ease in the video as he played the chess game and talked to Neuralinks' BCI software lead Bliss Chapman. He also used the cursor to pause a song that was playing in the background.

"It's all being done with my brain," Arbaugh said in the video. "It's crazy!"

In addition to playing chess, Arbaugh said he has used the device to play the computer game Civilization VI and to help him learn Japanese and French, presumably through the use of online programs.

Before receiving the Neuralink device, Arbaugh's computer-based exploits were limited to using a mouth stick or relying on family members to press buttons for him. "Now I can lie in bed and play to my heart's content," Arbaugh said.

Arbaugh also revealed that the surgery to implant the device was "super easy" and that he was discharged from the hospital a day later. He also said that he has had "no cognitive impairment" since the device was implanted.  

Regarding why he entered the trial, Arbaugh said, "I wanted to be a part of something that I feel like is going to change the world." 

"It has already changed my life," he added. "I'm so freaking lucky to be a part of this."

However, last month, experts expressed concerns at the lack of transparency surrounding Neuralink's first human trial and cautioned that, in general, BCIs could be susceptible to hacking, so transparency is warranted. 

In the past, critics have also voiced concerns about the ethics of artificially augmenting people's brains, specifically those without a need for such devices. Neuralink's devices are currently being tested as assistive technologies for people with paralysis, as are other similar devices made by other companies. But Musk has talked of people — including himself — eventually using Neuralink's implants for self-enhancement.

Chapman said in the livestream that Nerualink would release more information about the device and the initial trial in "the coming days."

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The brain activity of people who are easily offended is different from that of people who aren't as prone to getting riled up, a new study suggests.

Many people would consider a missed text from a best friend to be a harmless, accidental act. Maybe they're busy, or perhaps they read it and simply forgot to reply. However, some people are more likely to misconstrue this action as aggressive or hostile, thinking they're perhaps ignoring you on purpose. Scientists call this tendency to assume the worst in people "hostile attribution bias," and it can make people more likely to be aggressive, experience poor mental health and struggle to maintain healthy relationships. 

A new study suggests that people with hostile attribution bias display a unique signature of brain activity in part of the brain called the ventromedial prefrontal cortex (vmPFC) when another person's actions result in a negative outcome for them. Among other functions, the vmPFC is involved in emotional regulation, decision-making and self-perception. 

"The VmPFC is a high-order brain region that integrates sensory information about the external world with internal states and beliefs," Yuan Chang Leong, co-senior study author and an associate professor of psychology at the University of Chicago, told Live Science in an email. In other words, the vmPFC helps control how we react to social situations based on our already established biases.

Related: Neuralink chip implanted into human brain for the 1st time, Elon Musk says

The results of the new study, published Monday (Feb. 5) in The Journal of Neuroscience, suggest that the vmPFC plays a role in governing a person's interpretation of a social situation by integrating information about the unfolding scenario with their preconceived notions and memories, Leong said.  

Understanding the brain mechanisms behind hostile attribution bias could bring scientists a step closer to developing ways of mitigating it — for example, through more targeted interventions to reduce aggressive behavior and promote healthier relationships, the authors wrote in the paper. 

In the study, 58 volunteers listened to audio recordings of people describing 21 hypothetical social scenarios. On average, the mini-podcasts were around 40 seconds long and involved a character executing actions toward the listener — the study participant — that could have a negative effect on them. For instance, in one scenario, a professor forgot to write a letter of recommendation for the participant after they'd agreed to do so. 

After listening, the participants rated whether they thought these actions were intentional and hostile — for example, the professor was purposefully retaliating against them — or unintentional, meaning they simply forgot to write the letter. 

Throughout the experiment, each participant wore a fitted cap on their head that measured their brain activity using a technique called functional near-infrared spectroscopy (fNIRS). The researchers found that, during the recordings, fluctuations in brain cell activity in the vmPFC was similar among individuals with similar levels of hostile attribution bias and differed in those without the tendency. 

This suggests that this bias has steadily shaped how their brains respond to such scenarios, driving the activity to look the same, Leong said. Using the brain-activity readouts, the authors could predict with 75% accuracy whether someone had low or high hostile attribution bias, based on the pattern of activity in their vmPFC.

The authors also found that participants who exhibited less hostile attribution bias scored higher on a survey that assessed another psychological concept, called attribution complexity. This measures how likely someone is to consider that there may be many complex explanations for certain behaviors. 

As such, "fostering attributional complexity could be a potential strategy to mitigate hostile attribution bias and ultimately promote healthier social interactions," the authors wrote in the paper.

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The word resilience can be perplexing. Does it mean remaining calm when faced with stress? Bouncing back quickly? Growing from adversity? Is resilience an attitude, a character trait or a skill set? And can misperceptions about resilience hurt people, rather than help?

To sum it up in a sentence: Resilience is the ability to manage stress in effective ways. It's not a static quality or attribute you're born with, or a choice of attitude. Instead, it's a set of skills that can be developed by repeating specific behaviors. As a clinical psychologist, researcher and educator specializing in training people to cope with stress more effectively, I know that resilience can be developed.

But as with physical fitness, you can't get stronger abs by just wanting them. Instead, you have to repeat specific exercises that make your abs stronger; intention alone just won't do it.

Cultivating resilience is much the same. Like physical fitness, resilience is not a single quality but rather many ingredients that contribute differently to a range of strengths and situations. For instance, one may handle relationship issues rather well but be unable to cope with the stress of a traffic jam.

Related: COVID pandemic had 'minimal' effect on mental health, study says. Is that true?

Some building blocks of resilience are factors that are largely beyond one's control, such as greater income and education and having supportive environments. Some are things you can do in your daily life, such as exercise, hobbies and activities, and getting adequate sleep. Other facets might take more time to develop, such as nourishing supportive relationships, building skills for tolerating distress and regulating emotions, meditation, incorporating spirituality or religion and practicing less self-criticism and more self-compassion.

Resilience can be cultivated

Confusing connotations about resilience pervade not only the scientific literature and mental health approaches but also popular culture. The idea that difficult experiences make someone resilient is incorrect, or at least incomplete.

During the first year of the COVID-19 pandemic, I heard people claim that "children are resilient." However, one of the largest research investigations about difficult childhood experiences, the Adverse Childhood Experiences study, conducted in the 1990s at Kaiser Permanente with over 17,000 adults, established that cumulative stressors experienced in childhood impair both mental and physical health. It also found that more stress predicts worse outcomes.

What actually helped people be more resilient during the COVID-19 pandemic?

Studies show that the same building blocks mentioned above helped people navigate the pandemic with greater well-being. Many of these same building blocks also improve people's outcomes following other stressful experiences, such as unemployment, cancer, divorce and exposure to violence.

All of this says that resilience can flourish by incorporating specific behaviors and creating healthy environments. People often assume it's optimal to remain relatively unaffected by stress — that is, to "get over it" quickly. In many cases, that might be the case. If you forget an important meeting, for example, a response of "Oh no! I need to apologize right away and reschedule" is probably healthier than punching a wall or concluding that you're a terrible person.

But what if a relationship ends? Is it always best to get over it quickly, or could a longer reflection and healing process lead to deeper learning and growth? What looks like resilience could instead be suppressing, numbing or hiding feelings. Those tendencies are linked with worse mental health.

This is why the concept of resilience is somewhat nuanced; some people who seem resilient are just covering up, or coping in an unhealthy way — such as using alcohol to cope with difficult feelings.

Sometimes painful feelings or experiences contribute to personal development. Post-traumatic growth refers to the positive changes that some people report after trauma, especially when they incorporate some of the resilience "building blocks" listed above. This includes better relationships, a greater appreciation of life and enhanced spiritual or philosophical understanding. Rather than expecting yourself to always feel good or to bounce back quickly, in some situations it may be wise to allow yourself to experience deeply challenging feelings and the personal growth that can ensue.

Related: Earwax may reveal how stressed you are

Resilience isn't always the answer

Resilience is more complex than being mentally tough or not letting things get to you. Pressuring yourself to appear okay when you're not — also known as emotional perfection — could make things worse and prevent you from seeking support. Sometimes, changing stressful environments, such as a job or living situation, rather than just adapting to them is a healthier choice.

This is why resilience can be a loaded term. Although coping with challenges has its place, for trauma survivors, people who have experienced racism or homophobia, or those living in regions especially affected by climate change, and many others, resilience falls flat. The word comes across as tacitly accepting the status quo rather than demanding accountability from those who caused harm or working to reduce the sources of stress.

Overemphasizing resilience can reinforce racial injustice by suggesting that people who are subjected to it are resilient enough to handle it. Having to wear a mask of resilience or put on a smile can add to the burden of racism, making resilience exhausting. Having to continually adapt to microagressions and other forms of racism takes a mental and physical toll, such that resilience to racism comes at a cost.

A one-sized-fits-all approach to resilience doesn't work for every person and problem. But most of us can benefit from nourishing some of the building blocks of resilience, such as cultivating supportive relationships, physical exercise and self-compassion.

Becoming more resilient is a process. We can benefit from working on the building blocks of our own individual resilience, and from initiatives in schools, workplaces and other environments that promote resilience more broadly.

The number of factors affecting resilience may seem daunting. The upside is that you can choose from many effective ways of building resilience to determine the most suitable approach for you.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Electrical brain stimulation could temporarily make patients with chronic pain more susceptible to hypnosis, new research suggests. The researchers behind the study argue this could potentially offer patients a safer alternative to long-term opioid treatment for fibromyalgia, a chronic-pain condition. 

Opioids are not recommended to treat fibromyalgia under current guidelines. However, despite this, they are still sometimes prescribed to patients with the condition.

In a small clinical trial, scientists briefly applied electrical stimulation through the skulls of volunteers with fibromyalgia. The stimulation increased the volunteers' susceptibility to hypnosis for an hour — a trait that was once thought to be unchangeable.

The authors of the new study, published Thursday (Jan. 4) in the journal Nature Mental Health, believe that such stimulation could someday be used to increase patients' responsiveness to hypnotherapy, which has previously been investigated as a potential approach to treating fibromyalgia, although the data is limited.

As the U.S. contends with an ongoing opioid overdose epidemic, hypnotherapy may also provide a safer alternative to long-term use of these addictive drugs, the authors argue.

Related: Electrical stimulation could treat traumatic brain injuries

"Opioids are very dangerous — yes, they help control pain acutely, but they kill people chronically," Dr. David Spiegel, the co-senior study author and a professor of psychiatry and behavioral sciences at Stanford University, told Live Science.

Hypnosis is when a trained practitioner guides a person into an altered state of consciousness, which typically relaxes them and focuses their attention. The procedure has been tested to treat conditions such as stress and sleep disorders, and it's also been tested as a pain-reliever during surgery and as a method to help people quit smoking.

Around 15% of adults are considered "highly hypnotizable," meaning they'd score either 9 or 10 on a standard 10-point clinical scale of hypnotizability, while two-thirds of adults are "somewhat hypnotizable."

Scientists previously thought that hypnotizability was fixed, meaning your level of hypnotizability can't change. However, Spiegel and colleagues wanted to see whether they could change this by tweaking the electrical activity in people's brains.

Their trial included 80 patients with fibromyalgia who Spiegel said were "low-to-mid-range" in hypnotizability. The researchers used paddles held to the outside of the skull to stimulate a region of the brain called the dorsolateral prefrontal cortex, the brain's executive control region.

Their aim was to increase communication between the dorsolateral prefrontal cortex and part of what is known as the brain's "salience network," Spiegel said. This network acts like an alarm system that tells the brain to pay attention to new stimuli in our environment.

"Coordination between these two regions, the executive control region and the salience region, helps you to concentrate more intently and is something we see with more highly hypnotizable people," Spiegel said.

Related: This light therapy could zap away chronic pain one day

Half of the participants received two 46-second pulses of electricity to this region, while the others acted as a control group and didn't actually receive stimulation to the brain. Clinicians assessed each individual's hypnotizability before and after treatment. Patients had to follow a series of instructions during the hypnosis attempt, and their responses were rated out of 10.

Those who received stimulation showed a significant increase in their hypnotizability score compared with the control group, going up by about one point on the scale, on average. These effects lasted for only an hour, but Spiegel thinks that, with further refinement, the treatment could be useful for pain relief.

Hypnosis is not a treatment in itself, but more like a stepping stone: "Obviously the goal is not to get a bunch of people hypnotized, but to get them to use it to solve a problem and with fibromyalgia, it's pain," Spiegel said. Hypnosis can be used to help shift people's sensations, perceptions, thoughts or behaviors. When paired with talk therapy, it could potentially increase people's cognitive flexibility and receptiveness to new ideas, Spiegel said.

The authors plan to test longer lengths of stimulation to see if they observe greater improvements in hypnotizability, in terms of duration or greater increases on the 10-point scale.

Eventually, they'd like to see it developed into a clinical procedure that combines brain stimulation with hypnosis to reduce or eliminate pain.

This article is for informational purposes only and is not meant to offer medical advice.

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Tiny, hairlike "antennae" protrude from the surface of brain cells, and now, scientists have unveiled a detailed map of these wires across the whole human cortex. They hope the new map will guide future research into a class of diseases that cause these structures to malfunction.

The hairlike structures, known as cilia, are actually found on the surface of most eukaryotic cells, meaning complex cells that house their DNA in a nucleus. Some cilia can move; for example, cilia in the lungs collectively beat to clear the airways of harmful pathogens. Others, called primary cilia, are immobile and instead act like antennae, sensing signals from their environment and passing them to the nucleus of the cell.

In the brain, neurons and their associated helper cells, called glia, need primary cilia to effectively receive and send signals. However, until now, little has been known about cilia's structure or organization in the brain or how they slot into the network of interactions between neurons in the brain known as the "connectome."

In a new study, published Oct. 27 in the journal Neuron, scientists constructed a three-dimensional map of the primary cilia in the brain's outer layer, or cortex, which is part of the cerebrum, the largest portion of the brain. The researchers hope the new map, which details 56,000 cells, will guide research into ciliopathies, a class of diseases tied to disruptions in cilia function.

Related: Most detailed human brain map ever contains 3,300 cell types

"There are a number of cognitive difficulties associated with mutations in the proteins that make up cilia," co-senior study author, Dr. Jeff Lichtman, a professor of molecular and cellular biology at Harvard University, told Live Science in an email. "These studies may suggest that who a cilia contacts may be important in their normal function and when that function goes awry in disease."

To create the new map, the researchers pieced together images of the six layers of the human cerebral cortex; the images depicted "slices" of a tissue sample that had been collected during a surgery to treat an adult patient with epilepsy. One by one, the team looked at the cilia that emanated from each brain cell and studied how they interacted with one another.

The cilia differed in size and shape depending on the type of cell they interacted with and the layer of the cortex where they were located. Cilia were also a key component of the structure of some synapses — the junctions between neurons that allows these cells to communicate with each other — suggesting that cilia are firmly embedded in the brain's connectome.

The diversity of the cilia raises the "intriguing possibility" that different types of cilia in the cortex can regulate the activity of neurons in unique ways, the authors said.

Going forward, the team would like to delve further into how these primary cilia influence neural circuits in the brain and how this knowledge could be used to treat neurological disorders where cilial function is impeded, co-senior study author E. S. Anton, a professor of neuroscience at the University of North Carolina School of Medicine, told Live Science in an email. 

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It's a familiar feeling: Before a test, a first date, or a public speaking engagement, your stomach starts to "flutter" as if butterflies were flying around inside your gut. Stomach sensations are a common side effect of being nervous, and they may also manifest as a feeling of a "knot" or even as more severe digestive symptoms.

But where do these feelings actually come from?

It turns out, a "nervous stomach" is one of the best examples of the two-way connection between the digestive system and the nervous system.

"From the earliest stages of embryonic development, the brain, spinal cord and digestive tract are all tightly wired to each other," Melissa Hunt, a clinical psychologist at the University of Pennsylvania, told Live Science in an email. "Millions of neurons send information from the gut back to the brain, and just as many neurons send signals back to the gut."

This link is often referred to as the gut-brain axis. It's modulated by hormones and neurotransmitters — chemical messengers that respectively have broad effects via the bloodstream or act locally between nerve cells. It is also controlled by direct nerve connections between the brain and gut? and even by bacteria, and it's one reason your mood can so often affect the rest of your body, and vice versa.

"When we feel "butterflies" in our stomach, it's a vivid reminder that our emotions are deeply embodied," John Cryan, a professor of anatomy and neuroscience at University College Cork in Ireland, told Live Science in an email. "Ultimately, butterflies in the stomach illustrate the gut-brain axis in action: a continuous, bidirectional conversation between the central nervous system and the gut through neural, hormonal, and microbial pathways."

How the gut-brain axis creates butterflies in your stomach

The nerve cells that line the gastrointestinal tract are part of the "autonomic" nervous system, which regulates involuntary bodily functions, such as breathing, heartbeat and digestion. When food enters the gut, for example, its resident nerve cells prompt muscle cells to contract and push the food through the intestines, according to Harvard Health.

The autonomic nervous system is divided into two branches: the parasympathetic nervous system and sympathetic nervous system. These systems, respectively nicknamed the "rest and digest" and "fight or flight" systems, balance each other out. In general, the parasympathetic nervous system relaxes the body, while the sympathetic nervous system bolsters its response to danger.

When you're feeling anxious, the fight-or-flight response is activated. In this state, the body releases stress-related hormones, such as cortisol, that suppress digestion processes in the stomach and small intestine; meanwhile, other hormones actually stimulate the large intestine. These simultaneous changes cause muscle contractions that can feel like "butterflies" in the stomach, and they can also cause more severe digestive distress, such as nausea, bloating, constipation or diarrhea.

While these feelings often seem like an annoyance or inconvenience today, they may have once played a pivotal role in human life.

"From an evolutionary standpoint, this reaction likely helped our ancestors survive," Cryan explained. "Shutting down digestion and diverting resources toward immediate physical readiness would have improved chances of escape or confrontation. The gut sensations that accompanied these shifts also served as internal cues, highlighting moments of high importance or uncertainty."

You may have heard that the microbiome — the community of microorganisms that live in and on our bodies — plays a big role in the gut-brain axis. And that holds true for the sensation of a nervous stomach, too.

"Although the gut microbiome doesn't cause the flutter directly, it helps shape how strongly we experience and recover from such sensations," Cryan said. The bacteria in our guts may secrete substances that influence gut-brain signaling, and this, in turn, could affect how strongly someone feels a fluttery stomach.

"A healthy, diverse microbiome may buffer overactive stress responses, while alterations in microbiome composition can heighten them," Cryan suggested. The interactions between the microbiome and the gut-brain axis are still a relatively new area of research, and scientists are still determining how specific microbes influence gut-brain signaling.

Two-way road

Just as stress can trigger a nervous stomach, frequent gastrointestinal (GI) problems can also cause stress, Harvard Health notes.

What's more, stress can increase the frequency or severity of symptoms in "disorders of gut-brain interaction," or DGBIs. This umbrella term covers GI conditions that cause significant symptoms and impact quality of life but don't always trigger clear, measurable changes in the digestive tract. These include conditions like irritable bowel syndrome (IBS), in which a variety of symptoms, such as abdominal pain, diarrhea or constipation, occur without a clear cause; or functional dyspepsia, which involves stomachaches that occur during or after eating, without a known cause.

DGBIs are thought to be characterized by ongoing disturbances in communication between the gut and the brain, as well as shifts in the gut microbiome and immune function, in some cases. Over time, people can become anxious and hypervigilant about their GI symptoms, Hunt noted.

"This leads to visceral hypersensitivity, which becomes a vicious feedback loop of anxious arousal, scanning the body for uncomfortable sensations, catastrophizing, amplification of those sensations, which increases anxiety and then leads to increased GI discomfort and distress," she said.

That's why behavioral therapy is sometimes incorporated into patients' treatment plans for DGBIs, to help break this cycle.

"Far from being 'just in your head,' emotional experiences are woven through your viscera," Cryan said. "Understanding this connection reminds us that mental and digestive health are inseparable."

This article is for informational purposes only and is not meant to offer medical advice.

Scientists armed with a new computer model have taken a step closer to unlocking the mind-bending secrets of optical illusions that trick the brain into seeing the wrong colors when it's processing images. 

"Simultaneous contrast illusions" are a wide-ranging group of deceptive illustrations that trick people into thinking specific parts of an image are different colors from one another, when in reality, they're the same color. The effect rests on the illustrator altering the brightness or color in the background, in order to alter our perception of objects in the foreground. For example, in the image above, the smaller bar in the middle of the image is a single gray color but appears to be a gradient of varying shades because the background is brighter at one end and darker at the other. Another example is the Munker-White illusion, displayed in the image below, in which 12 spheres appear red, purple and green but are actually the same shade of beige.

Scientists have broadly known why these illusions work for more than a century, but in all that time, experts haven't been able to agree on exactly how they trick the brain. There are two possible explanations. The first is that the illusion is created from the bottom up, starting with low-level neural activity that requires no previous exposure to this type of illusion. The second is top-down, meaning it requires higher brain functions and plays off what your brain has previously learned about the brightness and color of light over time.

In a new study, published June 15 in the journal Computational Biology, a pair of researchers used a new computer model that mimics human vision to try to settle the debate once and for all.

Related: A new type of optical illusion tricks the brain into seeing dazzling rays

The model, known as the "spatiochromatic bandwidth limited model," uses computer code to mimic how the network of brain cells, or neurons, that first receive data from the eyes starts to decipher an image before that data is sent to other, "higher-level" regions of the brain to be fully processed. The model breaks down the image into sections, measures each section's brightness and then coalesces those assessments into a single report that can be sent to the brain, similar to what happens with human vision. 

The beauty of this model is that the code allows the individual sections to be processed only at the same speed as human neurons could feasibly assess them, so the model is restricted to match our own visual limitations, study co-author Jolyon Troscianko, a visual ecologist at the University of Exeter in the U.K., told Live Science. "This aspect of the model is particularly novel — no one seems to have considered the effect that limited bandwidth might have on visual processing," he added. Specifically, the new model takes into account how quickly neurons can "fire," or shoot a message to other neurons in their network. 

The researchers used their new model to analyze more than 50 simultaneous contrast illusions to see if the program would also mistakenly identify specific parts of the images as being different colors, as a human being would. (It is unclear exactly how many simultaneous contrast illusions exist, but there are likely hundreds, the report authors noted.)

During these experiments, the model was consistently fooled into identifying the wrong colors, Troscianko said. "My collaborator [Daniel Osorio] kept emailing me new illusions, saying that he didn't think it would work with this one," he added. "But to our surprise and delight, it generally predicted the illusion in almost all cases."

Because the model is also "tricked" by these illusions without the equivalent complex processing power of the human brain, it suggests that neither higher-order visual processing nor past experiences are required for these illusions to work. This seems to confirm the bottom-up hypothesis that says only basic-level neural processing is responsible for the images' deception, the authors concluded. 

"In essence, many illusions that were previously thought to rely on complex visual processing, or at least visual processing that requires feedback loops, can actually be explained with something as simple as a single layer of neurons," Troscianko said.

The results support similar findings from a 2020 study in the journal Vision Research. In that study, children who were born with cataracts but underwent successful cataract removal were fooled by the images shortly after regaining their sight, despite having no past visual experiences to provide context for the images.

Human beings can generate false memories of events mere seconds after they have occurred, a new study has found. 

The phenomenon, which researchers have dubbed "short-term memory illusions," shows how easily and rapidly humans reimagine experiences to fit our preconceptions, rather than accurately recording what takes place. The researchers published their findings April 5 in the journal PLOS One.

"It seems that short-term memory is not always an accurate representation of what was just perceived," the researchers wrote in the study. "Instead, memory is shaped by what we expected to see, right from the formation of the first memory trace."

Related: 'Muscle memories' get 'zipped and unzipped' in the brain, like computer files

To test the accuracy of short-term memories, the researchers enlisted 534 volunteers to take part in a series of four experiments, each designed around memorizing a sequence of letters of the Latin alphabet. 

In each round, participants were shown a collection of letters, arranged in a circle. Those letters would then disappear and a box would pop up at a specific position in the circle, to indicate which letter they should remember. Participants had to remember both the letter's identity and the direction it was facing, as some had been mirrored to face backwards. 

Sometimes, participants were shown a second, irrelevant batch of letters before their memory was tested. After giving the answer, they were then asked to score their confidence, from very low to very high, that they had guessed correctly. 

When the participants were asked to recall what they saw just a half second later, they were wrong just under 20% of the time, and this error rate shot up to 30% when asked three seconds later. When asked to recall whether a letter was facing forwards or backwards, participants who responded with high confidence had flipped the letter to its regular position 37% of the time, even though they had been explicitly warned that mirrored letters would appear in the tests and should not be mistakenly reported for real ones.

To confirm their findings, the researchers repeated the tests across three similar experiments with a cohort of 348 people not included in the original analysis, who showed the same tendency to mentally flip the mirrored letters. Across all experiments, this mental letter-flipping was the most common high-confidence error — a sign that human brains record experience based on preset notions (in this case, how a letter should appear) that enable us to generate better predictions about the world, while pruning out peculiarities that don't fit with those preconceptions.

"These memory illusions seem to be the result of world knowledge and not of visual similarities," the researchers wrote in the study. "Taken together, the results thus show that world knowledge can shape memory even when memories have only just been formed."

The researchers' next steps are to design experiments that could demonstrate similar short-term memory adjustments in real-world settings, as well as for other types of memory besides those related to visual and language-related stimuli.

A group of astrophysicists has proposed that individual planets are capable of developing intelligence — not the kind of smarts like knowing your ABCs, but rather an intelligence associated with the interconnectedness of the life inhabiting them. However, don't assume that our planet is in this intelligent league. Earth is still one major step away from developing true planetary intelligence, a milestone that, if achieved, could help us prevent the impending climate catastrophe, the scientists said. 

In the new study, published Feb. 7 in the International Journal of Astrobiology, a group of researchers argues that a planet can be deemed intelligent if it demonstrates cognition — the capacity to know something about what's happening and act on that knowledge. This could happen if nature and technology on planets like Earth can evolve to the point where they are so interconnected that they can recognize potential issues and create feedback loops to counter them.

"To be clear, cognition is not consciousness," the researchers wrote in an article for The Atlantic. "We don't imagine some kind of planetary super-being making self-aware decisions for the world." Instead, the team believes that cognition is a natural product of the relationship between life and the planets on which they develop.

Related: Changing Earth: 7 ideas to geoengineer our planet 

However, Earth hasn't entered this stage, at least not yet. "Even though Earth might be full of intelligent life, at this point in its cosmic history, it certainly doesn't seem very smart," they wrote in The Atlantic. But the new study does outline the remaining final hurdle Earth must overcome to gain true planetary intelligence. 

The Gaia hypothesis 

The new study is built upon a principle known as the Gaia hypothesis, an idea introduced by British scientist James Lovelock and American evolutionary biologist Lynn Margulis in the early 1970s. (Gaia is the personification of Earth from Greek mythology.)

The Gaia hypothesis states that, as life-forms evolve on Earth, they affect the evolution of the planetary system as a whole. The idea is that the biosphere — the global ecological system integrating all living things and their relationships — can physically alter other systems, such as the atmosphere (air), cryosphere (ice), hydrosphere (water) and lithosphere (land). This back-and-forth effect has been happening since life first began on Earth, but it has become more noticeable than ever due to humanity's impacts on the planet, including human-caused climate change, pollution and deforestation.

The researchers wanted to know if this interconnectedness between life and a planet could become so interwoven that the planet could eventually be deemed intelligent. "The biosphere tells us that once life appears in a world, that world can take on a life of its own," the researchers wrote in The Atlantic. "But if a planet with life has a life of its own, can it also have a mind of its own?"

The idea of a collective entity like a planet having some sort of intelligence goes against the notions we have about our own intelligence. "Intelligence tends to be conceived of as something that happens in individual heads, and usually those heads sit on the shoulders of animals like humans," the researchers wrote. However, there are many examples of collective intelligence in the natural world.

For instance, colonies of social insects, like bees, show a collective and often superior intelligence than the individuals that form them. "A single bee holds only a small amount of information about the world, but its colony as a whole knows and responds to the environment," the researchers wrote.

Related: Landsat satellites: 12 amazing images of Earth from space

Recent discoveries about fungal networks, known as mycorrhizal networks, that share water and nutrients between individual trees in forests also reveal a form of collective intelligence. "Such fungal networks allow forests stretching hundreds of miles to recognize and respond to changing conditions," the researchers wrote.

Meanwhile, the human brain is made from trillions of connections between different neurons, meaning our own intelligence is more collective than we think.

Stages of planetary intelligence 

The researchers define true planetary intelligence as the point at which all the living systems on a planet work in unison for the benefit of the entire system. This would involve feedback loops in which negative changes to the planet, such as rapid climate change, are identified and counteracted. 

"We consider planetary intelligence to be life's collective response to changes in the state of the entire planet," the researchers wrote. "The collective result is that life doesn't doom itself over time."

However, this does not happen overnight, and there are major obstacles planets must overcome before they can be deemed intelligent. In the new study, the researchers propose four main stages in planetary intelligence: immature biosphere, mature biosphere, immature technosphere and mature technosphere.

An immature biosphere is characteristic of Earth when life first emerged, when tiny microbes were the only life-forms on the planet. At that point, the atmosphere was mainly carbon dioxide and methane, which made the planet inhospitable to more advanced life-forms that we see today. "During this early period, life was not yet a major planetary player," the researchers wrote. "There was life, but there were few global feedback loops and hence no emergence of intelligence."

But the microbes created oxygen via photosynthesis, which began to slowly change the chemistry of the atmosphere. This allowed for the development of a mature biosphere, where multicellular life — such as animals and, most importantly, vegetation — emerged and further increased the oxygen in the atmosphere. This oxygen-rich environment allowed the protective ozone layer to form and plants and animals to develop on land and further transform the planet. 

"This thick tangle of feedback loops between living and nonliving components comprised a network that could be said to hold and respond to information in a meaningful way," the researchers wrote. "Earth, in other words, started to become smart."

Next, the researchers looked at the technosphere, or the relationship between artificial technology and natural systems. The immature technosphere materialized when humans began to develop technology and build networks for communication, transport, energy and food production. However, at this stage, these technologies come at the expense of the planet by using energy and resources from other living and physical systems. This rapidly transforms the planet by increasing the greenhouse gases in the atmosphere and introducing other damaging pollutants, as well as by destroying physical systems and ecosystems.

Related: 10 Signs that Earth's climate is off the rails

Earth is currently stuck at the immature technosphere stage, the researchers said. Our advancements in energy production are allowing us to achieve some remarkable technologies for ourselves, but those actions are significantly altering the planet. "Our technosphere is, in the long run, working against itself. It's formally stupid," the researchers wrote. "It leaves the entire planet unguided, careening into new and uncharted territory."

If Earth ever reaches the mature technosphere stage — a pivotal feat that would signify that Earth is "intelligent" — the technology on our blue dot will advance to a point where it does not require planetary energy and resources and instead can be used to repair and improve the systems it was destroying. This would allow the technosphere to co-evolve with the biosphere in a way that allows both to thrive. 

"This would be a technosphere rooted in the biosphere, which itself is rooted in the other planetary systems — a technosphere that self-maintains the entire Earth system," the researchers wrote.

The final hurdle 

Progressing to the final stage of planetary intelligence is more than just a curiosity for the researchers — it is a necessity. They believe that it may be the only way to prevent a climate catastrophe, which is nearing ever closer due to the immaturity of our technosphere. 

"Humanity stands at a most precipitous moment in both our and our planet's evolution," the researchers wrote. It is "caught in a climate crisis brought on by our supposed advancement as a civilization." 

However, thinking about intelligence on a wider scale could help us solve this problem. "Making sense of how a planet's intelligence might be defined and understood helps shine a little light on humanity's future on this planet — or lack thereof," the researchers wrote.

But it is unclear exactly how we should go about advancing our technosphere, what further discoveries or breakthroughs we need to make in order to do this. "The million-dollar question is figuring out what planetary intelligence looks like and means for us in practice because we don't know how to move to a mature technosphere yet," lead author Adam Frank, an astrophysicist at the University of Rochester in New York, said in a statement.

However, there is hope that humans can help the planet take the final step toward intelligence, because we are smart enough to realize that it is even a possibility. "Humans at least are intelligent enough to comprehend the calamitous direction we're headed in," the researchers wrote. "That level of self-awareness opens some possibility of choice."

Related: 7 ways to prove the Earth is round (without launching a satellite)

In the past, humanity has made some choices that benefit the planet, such as the 1987 establishment of the Montreal Protocol, in which countries around the world agreed to ban hazardous chemicals that were destroying the ozone layer. "That was, perhaps, an early example of what the new version of planetary intelligence could look like," the researchers wrote.

Extraterrestrial technosignatures 

The researchers' study focuses mainly on Earth's journey toward intelligence. But the same interconnectedness between life and host planets is likely to be the same on any alien worlds that may harbor life elsewhere in the cosmos. 

"We have discovered that the universe is teeming with worlds, many of which might host life and even intelligence," the researchers wrote. However, current searches for intelligence tend to focus on whether planets might harbor intelligent life and not on whether the planets are intelligent themselves, they added.

Most alien-life hunters are focused on finding evidence of an intelligent species reaching outward, such as radio signals. But examples of planetary intelligence, known as technosignatures, are more likely to be on the planets themselves, like solar panels or pollution.  

"Understanding planetary intelligence might help point the way to knowing what kind of technosignatures we should be looking for, as well as how to look for them," the researchers wrote. Frank is now the principal investigator on the first NASA project looking for non-radio technosignatures, according to the statement. 

Originally published on Live Science.

We are highly sensitive to people around us. As infants, we observe our parents and teachers, and from them we learn how to walk, talk, read — and use smartphones. There seems to be no limit to the complexity of behavior we can acquire from observational learning.

But social influence goes deeper than that. We don't just copy the behavior of people around us. We also copy their minds. As we grow older, we learn what other people think, feel and want — and adapt to it. Our brains are really good at this — we copy computations inside the brains of others. But how does the brain distinguish between thoughts about your own mind and thoughts about the minds of others? Our new study, published in Nature Communications, brings us closer to an answer.

Our ability to copy the minds of others is hugely important. When this process goes wrong, it can contribute to various mental health problems. You might become unable to empathize with someone, or, at the other extreme, you might be so susceptible to other people's thoughts that your own sense of "self" is volatile and fragile.

The ability to think about another person's mind is one of the most sophisticated adaptations of the human brain. Experimental psychologists often assess this ability with a technique called a "false belief task."

In the task, one individual, the "subject", gets to observe another individual, the "partner", hide a desirable object in a box. The partner then leaves, and the subject sees the researcher remove the object from the box and hide it in a second location. When the partner returns, they will falsely believe the object is still in the box, but the subject knows the truth.

This supposedly requires the subject to hold in mind the partner's false belief in addition to their own true belief about reality. But how do we know whether the subject is really thinking about the mind of the partner?

False beliefs

Over the last ten years, neuroscientists have explored a theory of mind-reading called simulation theory. The theory suggests that when I put myself in your shoes, my brain tries to copy the computations inside your brain.

Neuroscientists have found compelling evidence that the brain does simulate the computations of a social partner. They have shown that if you observe another person receive a reward, like food or money, your brain activity is the same as if you were the one receiving the reward.

There's a problem though. If my brain copies your computations, how does it distinguish between my own mind and my simulation of your mind?

In our experiment, we recruited 40 participants and asked them to play a "probabilistic" version of the false belief task. At the same time, we scanned their brains using functional magnetic resonance imaging (fMRI), which measures brain activity indirectly by tracking changes in blood flow.

In this game, rather than having a belief that the object is definitely in the box or not, both players believe there is a probability that the object is here or there, without knowing for certain (making it a Schrödinger's box). The object is always being moved, and so the two players' beliefs are always changing. The subject is challenged with trying to keep track of not only the whereabouts of the object, but also the partner's belief.

This design allowed us to use a mathematical model to describe what was going on in the subject's mind, as they played the game. It showed how participants changed their own belief every time they got some information about where the object was. It also described how they changed their simulation of the partner's belief, every time the partner saw some information.

The model works by calculating "predictions" and "prediction errors." For example, if a participant predicts that there is a 90% chance the object is in the box, but then sees that it's nowhere near the box, they will be surprised. We can therefore say that the person experienced a large "prediction error." This is then used to improve the prediction for next time.

Many researchers believe that the prediction error is a fundamental unit of computation in the brain. Each prediction error is linked to a particular pattern of activity in the brain. This means that we could compare the patterns of brain activity when a subject experiences prediction errors with the alternative activity patterns that happen when the subject thinks about the partner's prediction errors.

Our findings showed that the brain uses distinct patterns of activity for prediction errors and "simulated" prediction errors. This means that the brain activity contains information not only about what's going on out there in the world, but also about who is thinking about the world. The combination leads to a subjective sense of self.

Brain training

We also found, however, that we could train people to make those brain-activity patterns for self and other either more distinct or more overlapping. We did this by manipulating the task so that the subject and partner saw the same information either rarely or frequently. If they became more distinct, subjects got better at distinguishing their own thoughts from the thoughts of the partner. If the patterns became more overlapping, they got worse at distinguishing their own thoughts from the thoughts of the partner.

This means that the boundary between the self and the other in the brain is not fixed, but flexible. The brain can learn to change this boundary. This might explain the familiar experience of two people who spend a lot of time together and start to feel like one single person, sharing the same thoughts. On a societal level, it may explain why we find it easier to empathise with those who've shared similar experiences to us, compared with people from different backgrounds.

The results could be useful. If self-other boundaries really are this malleable, then maybe we can harness this capacity, both to tackle bigotry and alleviate mental health disorders.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

Humans have learned to travel through space, eradicate diseases and understand nature at the breathtakingly tiny level of fundamental particles. Yet we have no idea how consciousness — our ability to experience and learn about the world in this way and report it to others — arises in the brain.

In fact, while scientists have been preoccupied with understanding consciousness for centuries, it remains one of the most important unanswered questions of modern neuroscience. Now our new study, published in Science Advances, sheds light on the mystery by uncovering networks in the brain that are at work when we are conscious.

It's not just a philosophical question. Determining whether a patient is "aware" after suffering a severe brain injury is a huge challenge both for doctors and families who need to make decisions about care. Modern brain imaging techniques are starting to lift this uncertainty, giving us unprecedented insights into human consciousness.

For example, we know that complex brain areas including the prefrontal cortex or the precuneus, which are responsible for a range of higher cognitive functions, are typically involved in conscious thought. However, large brain areas do many things. We therefore wanted to find out how consciousness is represented in the brain on the level of specific networks.

The reason it is so difficult to study conscious experiences is that they are entirely internal and cannot be accessed by others. For example, we can both be looking at the same picture on our screens, but I have no way to tell whether my experience of seeing that picture is similar to yours, unless you tell me about it. Only conscious individuals can have subjective experiences and, therefore, the most direct way to assess whether somebody is conscious is to ask them to tell us about them.

Read more: The way you see colour depends on what language you speak

But what would happen if you lose your ability to speak? In that case, I could still ask you some questions and you could perhaps sign your responses, for example by nodding your head or moving your hand. Of course, the information I would obtain this way would not be as rich, but it would still be enough for me to know that you do indeed have experiences. If you were not able to produce any responses though, I would not have a way to tell whether you're conscious and would probably assume you're not.

Scanning for networks

Our new study, the product of a collaboration across seven countries, has identified brain signatures that can indicate consciousness without relying on self-report or the need to ask patients to engage in a particular task, and can differentiate between conscious and unconscious patients after brain injury.

When the brain gets severely damaged, for example in a serious traffic accident, people can end up in a coma. This is a state in which you lose your ability to be awake and aware of your surrounding and need mechanical support to breathe. It typically doesn't last more than a few days. After that, patients sometimes wake up but don't show any evidence of having any awareness of themselves or the world around them — this is known as a "vegetative state". Another possibility is that they show evidence only of a very minimal awareness — referred to as a minimally conscious state. For most patients, this means that their brain still perceives things but they don't experience them. However, a small percentage of these patients are indeed conscious but simply unable to produce any behavioural responses.

We used a technique known as functional magnetic resonance imaging (fMRI), which allows us to measure the activity of the brain and the way some regions "communicate" with others. Specifically, when a brain region is more active, it consumes more oxygen and needs higher blood supply to meet its demands. We can detect these changes even when the participants are at rest and measure how it varies across regions to create patterns of connectivity across the brain.

We used the method on 53 patients in a vegetative state, 59 people in a minimally conscious state and 47 healthy participants. They came from hospitals in Paris, Liège, New York, London, and Ontario. Patients from Paris, Liège, and New York were diagnosed through standardised behavioural assessments, such as being asked to move a hand or blink an eye. In contrast, patients from London were assessed with other advanced brain imaging techniques that required the patient to modulate their brain to produce neural responses instead of external physical ones — such as imagining moving one's hand instead of actually moving it.

We found two main patterns of communication across regions. One simply reflected physical connections of the brain, such as communication only between pairs of regions that have a direct physical link between them. This was seen in patients with virtually no conscious experience. One represented very complex brain-wide dynamic interactions across a set of 42 brain regions that belong to six brain networks with important roles in cognition (see image above). This complex pattern was almost only present in people with some level of consciousness.

Importantly, this complex pattern disappeared when patients were under deep anaesthesia, confirming that our methods were indeed sensitive to the patients' level of consciousness and not their general brain damage or external responsiveness.

Research like this has the potential to lead to an understanding of how objective biomarkers can play a crucial role in medical decision making. In the future it might be possible to develop ways to externally modulate these conscious signatures and restore some degree of awareness or responsiveness in patients who have lost them, for example by using non-invasive brain stimulation techniques such as transcranial electrical stimulation. Indeed, in my research group at the University of Birmingham, we are starting to explore this avenue.

Excitingly the research also takes us as step closer to understanding how consciousness arises in the brain. With more data on the neural signatures of consciousness in people experiencing various altered states of consciousness — ranging from taking psychedelics to experiencing lucid dreams — we may one day crack the puzzle.

Davinia Fernández-Espejo, Senior Lecturer, School of Psychology and Centre for Human Brain Health, University of Birmingham

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The amazing brain

The brain sculpts not only who we are but also the world that we experience. It tells us what to see, what to hear and what to say. It expands to accommodate a new language or skill that we learn. It tells stories when we're sleeping. It sends alarm signals, and it spurs the body to run or fight when it senses danger. The brain adapts to environments so we aren't annoyed by a constant smell in an old house or the constant hum of the air conditioning. Our brains look to the sun and tell our body what time it is. The brain stores memories, both painful and pleasant.

But as essential as the brain is to our existence, it's still as mysterious to us as a planet from a far-flung galaxy. Even in 2018, neuroscientists are still discovering fundamental facts about this roughly 3-lb. (1.4 kilograms) bulk of tissue. Sometimes, researchers get a glimpse of a human brain or see what happens to a person when a large bulk of the brain is missing. Other times, scientists must study mice to learn more about mammalian brains and then do some guesswork on how those findings relate to our own brains.

Here are some fascinating things we learned about the brain in 2018.

A new kind of neuron

It's not every day that scientists discover a completely new type of cell in the human brain, especially one that's not found in neuroscientists' favorite nonhuman subjects, mice. The "rosehip neuron," so named because of its bushy appearance, had eluded scientists until this year, partly because it's so rare.

This elusive brain cell makes up only about 10 percent of the first layer of the neocortex, one of the newest parts of the brain in terms of evolution (meaning the far-distant ancestors of modern humans didn't have this structure). The neocortex plays roles in vision and hearing. Researchers don't yet know what the rosehip neuron does, but they found that it connects to other neurons called pyramidal cells, a type of excitatory neuron, and puts the brakes on them.

[Read more about the rosehip neuron]

U.D., the neuroscience patient

A boy, known in the medical literature as "U.D." had one-third of the right hemisphere of his brain removed four years ago in order to reduce his debilitating seizures. The part of the brain that was removed included the right side of his occipital lobe (the brain's vision-processing center) and most of his right temporal lobe, the brain's sound-processing center. Now age 11, U.D. can't see the left side of his world, but he functions just as well as others his age in cognition and vision processing, even without that key part of the brain.

That's because both sides of the brain process most aspects of vision. But the right is dominant in detecting faces, while the left is dominant in processing words, according to a case study written about U.D.

That study showcases the plasticity of the brain; in the absence of U.D.'s right vision-processing center, the left center stepped in to compensate. Indeed, researchers found that the left side of U.D.'s brain detected faces just as well as the right would have.

[Read more about U.D.]

The brain may contain bacteria

Our brains might be teeming with bacteria. But don't worry — it doesn't look like they cause any harm.

Previously, scientists thought that the brain was a bacteria-free environment and that the presence of microbes was a sign of disease. But preliminary findings from a study presented this year at the large annual Society for Neuroscience scientific meeting found that our brains could actually house harmless bacteria.

The researchers in that study had been examining 34 postmortem brains, looking for differences between those with schizophrenia and those without the condition. However, the researchers kept happening upon rod-shaped objects in their images, and these shapes turned out to be bacteria.

The microorganisms seemed to dwell in some spots in the brain more than in others; those areas included the hippocampus, the prefrontal cortex and the substantia nigra. The microbes were also found in brain cells called astrocytes that were near the blood-brain barrier, the "border wall" that guards the brain.

The findings haven't been published in a peer-reviewed journal yet, and more research is needed to confirm the findings, the scientists said.

[Read more about bacteria in the brain]

The brain is magnetic

Our brains are magnetic. Or, at least, brains contain particles that can be magnetized. But scientists don't really know why these particles are in the brain or where they originated. Some researchers believe that these magnetizable particles serve a biological purpose, while others say the particles got into the brain because of environmental contamination.

This year, scientists mapped out where these particles are located in the brain. The results of their study, the researchers said, provide evidence that the particles are there for a reason. That's because in all the brains the scientists examined — from seven people who died in the early 1990s between ages 54 to 87 — the magnetic particles were always concentrated in the same areas. The investigators also found that most parts of the brain contained these little magnets.

Many animal brains also have magnetic particles, and there's even some suggestion that animals use these particles to navigate. What's more, a type of bacteria called magnetotactic bacteria use the particles to orient themselves in space.

[Read more about our magnetic brain]

Virus responsible for human consciousness?

An ancient virus infected people long ago, and this invader left behind its genetic code in our DNA. This year, researchers found that snippets of that ancient viral DNA play a vital role in the communication among brain cells that's required for higher-order thinking.

It's not uncommon for humans to carry around snippets of viral genetic code; around 40 percent to 80 percent of the human genome consists of genes left behind by viruses.

In the study this year, the researchers found that a viral gene called Arc packages up other genetic information and sends it off from one nerve cell to the next. This gene also helps cells reorganize over time. What's more, problems with the Arc gene tend to occur in people who have autism or other neural disorders.

Researchers now hope to figure out the exact mechanism by which the Arc gene got into our genome and what exactly it's telling our brain cells.

[Read more about this ancient virus]

Young cells in old brains or nah?

Our bodies continuously dispose of old cells and make new ones. But for decades, scientists believed that this cell turnover didn't happen in aging brains. In recent years, however, studies done in mice — and some early studies done in humans — have raised questions about this notion.

This year, a paper provided what may be the first strong evidence that older brains do make new cells. The researchers studied 28 postmortem, nondiseased brains from people who were ages 14 to 79 when they died. The scientists sliced up each brain's hippocampus, an area of the brain that's important for learning and memory, then counted the number of young cells that weren't fully mature. The researchers found that older brains had as many new cells as younger brains did but that the older brains made fewer new blood vessels and connections among brain cells.

To complicate matters, however, a different study, published a month before this one, found the opposite, concluding that adult brains do not make new cells in the hippocampus. The disagreement could be due to the way the brains were preserved in the two studies and the kinds of brains that were examined. (The earlier study looked at brains with different health conditions, while the later research looked at only nondiseased brains. They could have also used different preservation techniques which could affect the cells.)

[Read more about young cells in old brains]

Your brain on stress

Bad news: Stress may shrink the brain. That's according to a study published in October of this year.

In the study, researchers looked at more than 2,000 healthy, middle-age people and found that those with higher levels of the stress hormone cortisol had slightly smaller brain volumes than people with normal amounts of the hormone. People with higher cortisol levels also performed more poorly on memory tests than did people with normal levels of the hormone. Both findings, it should be noted, are associations between stress and the brain and not cause-and-effect findings.

Stress is normal for the body: During moments of stress, cortisol levels rise along with those of another hormone, adrenaline. These hormones work together to throw your body into a fight-or-flight response. But once the stressful part is over, cortisol levels should decrease. They don't always do this, however. Some people, especially in this modern life, can have elevated levels of cortisol for long periods of time. Reducing stress — such as by getting better sleep, getting exercise, engaging in relaxation techniques and taking cortisol-reducing medication — could have a range of benefits, the researchers said.

[Read more about your brain on stress]

Does your brain let you hear your own footsteps?

Click, click, click: You might have your brain to thank for sparing you from hearing every single step you take. A study conducted in mice this year found that the mouse brain canceled out the sound of the critter's own footsteps. This allowed the creatures to better hear other sounds in their surroundings, such as the noises of a predator.

The researchers found that the mouse brain built a noise filter as the brain got acclimated to a specific sound. It did this by coupling cells in the motor cortex, an area of the brain that's involved with movement, to the auditory cortex, an area involved with sound. Simply put, brain cells in the motor cortex fire signals to block brain cells in the auditory cortex from firing their own signals — essentially muting the auditory cortex.

And though the study was done in mice, the scientists think that the results could also apply to humans. That's because we have similar systems in place already. For example, figure skaters' brains learn what movements to expect, and inhibitory neurons cancel out reflexes that would prevent these athletes from spinning and performing their crazy twirls.

[Read more about this noise-canceling filter]

Psychedelic drugs may change the structure of brain cells

Psychedelic drugs can physically change the structure of brain cells, according to a new study. This research was conducted on brain cells in lab dishes and in animals, but if the findings hold true for humans, the results could mean that these drugs can help people who have certain mood disorders.

That's because in people with depression, anxiety or other mood disorders, neurons in the prefrontal cortex, a part of the brain important for controlling emotions, tend to shrivel up. And their branches — which neurons use to talk to other neurons — tend to retract. But when the scientists added psychedelic drugs including LSD and MDMA to petri dishes with rat neurons, they found that the number of connections and branches in the nerve cells increased.

[Read more about how psychedelics change the brain]

A second brain in the gut?

Millions of brain cells live in the large intestine, and because these cells function without any instructions from the brain or spine, scientists sometimes refer to the mass of them as "the second brain." But this mass also has a scientific name: the enteric nervous system. And a new study, done in mice, shows that the system is pretty smart; it can fire synchronized neurons to stimulate muscles and coordinate their activity so that it can do things like move feces out of the body.

The actual brain (the one in your head) can also do this — synchronize the firing of neurons — in the early stages of brain development. This means that the neuron actions in the gut could be a "primordial property" from the first stages of the second brain's evolution. Some scientists even hypothesize that the second brain evolved before the first and that this firing pattern comes from the earliest functioning brain in the body.

[Read more about this smart second brain]

It's extremely easy to trick our brains — and we are oddly delighted by it. But there's also a practical side to illusions, learning about where the brain gets confused can help us understand how it works to organize information in the first place.

Sometimes, a few splashes of color arranged in a very specific way can scream "mistake" to the brain. In response, brain cells will begin to fire to "correct" our vision … and the scene will disappear. Other times, an image that looks like a duck can look like a rabbit if you really try to see it. But the brain won't let you see both the rabbit and the duck at the exact same time, you have to tell it a story first. And it's not only vision that tricks us — the same recording of a word can sound like "Yanny" to some people and "Laurel" to others. What you see or hear, is not always what's happening.

Here are some of Live Science's favorite illusions from 2018.

Time travel

This illusion might not help you go back and un-spill your coffee all over a stranger, but it will bring you back in time — if only for a second. The video demonstrates a concept known as "postdiction" (like "prediction," but after, not before) , the idea that watching a new stimulus can change a person's perception of a stimulus that happened a mere split-second prior.

To see the illusion in action, watch the video with sound and count the number of flashes you see. 

In reality, there are two flashes. But the first time around, there are three beeps, with one sounding off in the middle of the two flashes, so the brain uses "postdiction" to fill in an extra flash in between the two real ones, thinking that you must have simply missed it. It also shows how sound and vision can be intertwined and throw each other off, if only to joke around.

[Read more about these flashes and beeps]

Right arrow

2018 wasn't just a year for optical illusions — there was also an auditory illusion that swept the internet in May of this year. Enter Yanny and Laurel. 

Why did these two words tear people apart? Yanny and Laurel both have the same timing and energy content as words, so they're easily interchangeable, experts said. In fact, there's no "true" word — in other words, no right answer —  but instead, a set of frequencies for your brain to interpret. One idea is that the brain picks a word and convinces itself that it's the correct interpretation, so that's what you hear. In addition, your past experiences and expectations can shape whether you hear Yanny or Laurel. So can your age, your ear shape and even your speakers.

[Read more about Yanny and Laurel]

Young, old woman 

"My Wife and My Mother-in-Law" is an illusion that first appeared on a German postcard at the end of the 19th century. The image shows two. There are two ladies in the image, a young woman with her head turned over her shoulder and an old woman looking straight ahead. But which woman you see initially could depend on how old you are, according to a study published this year.A new study this year found that how old you are could influence who you see first. Using thean online crowd-sourcing platform called Amazon's Mechanical Turk, researchers found that younger people tended to see the younger woman, whereas the older population saw the older woman. The researchers also asked the participants to estimate the age of the woman. The younger the participant was, the younger they said the woman was. The reason could be due to an "own-age-bias," which means we process faces from ages similar to our own more thoroughly than faces of other ages, or it could be due to sociocultural practices of being less inclusive to the elderly, according to the paper. 

[Read more about this ageless woman]

Physical activity is good for both the body and mind. Indeed, doctors have long known that exercise improves thinking and slows the rate of cognitive decline, particularly among older adults. But what kind — and how much — exercise is needed to achieve a healthier brain?

The answer seems to be just about any kind of exercise that gets you moving, as long as you stay with it, according to an international study published yesterday (May 30) in the journal Neurology Clinical Practice.

Walking, running, weight training, yoga or tai chi … it's all good, provided you do it a few times a week for at least 52 hours over the course of six months or so. A key finding in the study was that the exercise doesn't need to take place within a set number of hours per day or week. [7 Ways the Mind and Body Change With Age]

"The real-world impact is that you can break that [52 hours] up" into an hour here or there, said lead study author Joyce Gomes-Osman, a clinical neuroscientist at the University of Miami Miller School of Medicine. "This is encouraging, because it tells you that you may not necessarily need an hour a day. If you exercise a few days a week and start racking up those 'points,' and you do this over several months and you get to that 52-hour mark, this is when you can expect that your mind is going to become sharper."

Gomes-Osman noted that low-intensity "mind-body" exercises (such as yoga and tai chi) work just as well as high-intensity, strength-training and aerobic exercises.

The new research examined nearly 100 previously published studies on exercise and cognition, with a total of more than 11,000 participants whose average age was 73. The common denominator across all these studies was that various forms of exercise all led to sharper thinking if the participants achieved this minimum 52-hour target over roughly six months, Gomes-Osman said. Studies with fewer hours of exercise or shorter time scales did not yield positive results.

Gomes-Osman told Live Science that, as a neuroscientist practicing physical therapy, she has long desired to prescribe a "dose" of exercise to her patients, employing the same precision and individualized approach that a physician would use to prescribe a heart medication. Now, she's closer to that goal, she said.

"We often hear advice to be more active" given with the aim of improving thinking, Gomes-Osman said. But, "What does that mean? Does that mean the person needs to do 30 minutes a day every weekday? Or an hour a day? And what kind of exercise?"

Referring back to heart disease, Gomes-Osman said there are recommendations for the precise amount of rigorous or moderate exercise needed to improve heart health. But a corresponding dose of exercise for cognitive health was not known … until now. This is an important new understanding, she said, because there are no drugs to improve or slow cognitive decline. Exercise, for now, is the only approach.

Dr. Douglas Scharre, director of the Center for Cognitive and Memory Disorders at The Ohio State University Wexner Medical Center, who was not involved with new research, agreed with the study's conclusions.

"I believe that the take-home message is that physical exercise should be done consistently for the long term to gain maximum cognitive benefits," Scharre told Live Science. "It does not seem to matter how much or how long or what type of exercise, just that you do it regularly over the long term."

The researchers found that real cognitive gains were in specific areas of thinking — namely, planning and initiation of tasks, processing speed and executive function, which is the ability to focus and manage tasks, Gomes-Osman said. Her team found that participants’ memory improvement was only seen in about half of the studies analyzed, so averaged together, they could not conclude that exercise improved memory.

That makes sense, according to Scharre, because those nonmemory elements of cognition make common use of frontal brain regions that get more of a workout during exercise than brain regions related to memory. [10 Things You Didn't Know About the Brain]

"Exercise is a fabulous brain activity," Scharre said. "The brain is being activated very much during exercise. We have to learn how to control our muscles to do the exercise; we need to focus attention on doing the tasks; we have to determine if we are feeling tired or … plan to go slower the next time to avoid a certain activity that causes pain. Basically, 'use it or lose it,' I believe, is just as true for the brain as it is for muscles."

Scharre added that watching TV and not socializing does not use your brain as much as exercise.

The researchers, who include scientists from Brazil and Spain, wrote that those brain functions that consistently improved with exercise across all studies examined — processing speed, planning and focus — are the very same functions that start to falter with the onset of age-related cognitive decline.

Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.

Nectome wants to back up your consciousness when you die. But now, after MIT cut ties with the company, its founders have emphasized to Live Science that they don't plan to actually attempt the feat anytime soon.

The startup came under criticism from a number of prominent neuroscientists, including two who spoke to Live Science, after a favorable article appeared in MIT Technology Review on March 13. At the center of the article was the company's promise of a "100-percent-fatal" service for backing up and (eventually) digitizing people's brains.

Nectome's founders told Technology Review that their goal is to figure out how to preserve the brains of dying people in incredible detail. To that end they had developed a process that could turn a brain into a shelf-stable version of itself, with all the links between its neurons visible under a scanning electron microscope. Those links, Nectome suggested, could one day be used to revive dead people's consciousnesses. [Top Ten Mysteries of the Mind]

The article revealed that Nectome had already consulted with lawyers about the legality, under California's physician-assisted suicide law, of using their methods on terminal patients. (Their preservation methods would kill anyone subjected to them.) Technology Review also touted Nectome's relationship with MIT Media Lab neuroscientist Ed Boyden, whose collaboration with the company appears to have ended according to an MIT announcement.

In an email to Live Science this morning (April 3), Nectome co-founder Robert McIntyre said the company had no plans to actually do this in the foreseeable future.

"We have not nor do we plan to administer embalming fluids on a living animal or human," he wrote.

A reference to being able to "back up" people's minds, along with other ambitious language, appears to have disappeared from Nectome's website. It has been replaced with more cautious wording and a statement emphasizing that Nectome's current research represents just a "promising first step" toward its eventual goals.

McIntyre also said that an earlier article from Live Science, stating that the "company wants to flood the arteries of living people who have terminal illnesses with embalming fluid to preserve their brain tissue" gave people the incorrect impression that Nectome is currently doing this.

"I want people to understand that we're currently in the research phase, and that rushing to apply ASC [aldehyde-stabilized cryopreservation] today would be irresponsible," he wrote.

The extent of Nectome's research right now involves preserving the brains of donated cadavers, he emphasized.

Connectome Conflicts

Nectome, founded by MIT graduates and supported by the famous Silicon Valley startup incubator Y Combinator, has received more than $915,000 in grant funding from the National Institute of Mental Health (NIMH). The company has worked with Boyden, under the now-cancelled subcontract agreement, to achieve something genuinely impressive: preserving a pig's brain well enough that every one of its neural links was intact and visible under a scanning electron microscope. The accomplishment won the company an $80,000 prize from The Brain Preservation Foundation.

The pig brain is a big deal because if you manage to preserve a creature's brain at that level of detail, you've preserved what neuroscientists call its "connectome." A connectome is a map of all the links between nerves in a brain; it describes, at the very least, the routes by which signals get around inside the skull, if not the content of the signals themselves.

The suggestion that the connectome offered enough information about the brain that it might be used to revive people was the core of what rankled many neuroscientists.

"Can I reconstruct all memories knowing only the connections between neurons? The answer is almost certainly no, given our knowledge about how memories are stored — itself a controversial topic," Sam Gershman, a Harvard neuroscientist, previously told Live Science.

"It's true that synapses are where all the action happens," Florida State University neuroscientist Jens Foell previously told Live Science. "But cell firing behavior is determined by other things, including processes within the cells that are determined by proteins that are much smaller than synapses — and some of them are short-lived."

Not every neuroscientist had such a negative take on the company and its claims. Sebastian Seung, a connectome expert and neuroscientist at Princeton University, has been a somewhat lonely public voice defending the company, both on Twitter and in emails to Live Science.

He has argued that while it may be unlikely that Nectome's technique could preserve enough information to revive memories and consciousness, other neuroscientists can't know for certain that it doesn't.

(Seung does not have direct involvement in Nectome, but a video of his TED Talk on the connectome appears on Nectome's website, and he was part of the panel that awarded the company its prize for the preserved pig.)

McIntyre, in his email to Live Science, said it wasn't correct that Nectome expected to revive a whole consciousness from the connectome.

"We at Nectome are big fans of the connectome. Our name, Nectome, literally comes from the word connectome. But we don't mean to imply that electron microscope image data is the only thing we would need to reconstruct consciousness or even memories," he wrote, adding, "The connectome is not the only step, but it is the vital first step towards putting together biologically and informationally accurate models of brains."

Next steps

MIT's statement announcing it had ended its subcontract with Nectome explicitly criticized the company's scientific claims.

"…Currently, we cannot directly measure or create consciousness," the MIT statement said. "Given that limitation, how can one say if, for example, a computer or a simulation is conscious?"

The statement also suggests it may be possible to one day simulate consciousness in a computer but that currently, the company does "not know how to determine what such a simulation, even if scaled up to the size of the human brain, would 'feel' like. To understand this will require new science that represents a nonlinear jump from the neuroscience occurring today, and some people regard this as an unsolvable problem (aka the 'hard problem' of consciousness)."

When asked to comment on MIT's statement, McIntyre wrote, "Neuroscience has historically progressed by a mixture of sustaining innovation (which I suspect is what is meant by 'occurring today') and disruptive innovation (nonlinear jumps). We believe that understanding what a simulation feels like is an achievable goal, and it's part of our vision, though clearly not what can be promised today."

Right now, Nectome has more immediate obstacles to overcome.

The company's active NIMH grant is "in transition" following MIT's announcement, McIntyre wrote.

"We cannot comment on precisely what that means, as that remains to be determined with MIT, NIMH, and Nectome," he said. However, he added, "Our high-level plans for Nectome are still the same: to continue developing tools like ASC [the preservation process], and to advance the field of neuroscience as best we can through our research."

As for the company's relationship with MIT, he made it clear that Nectome didn't see the end of the subcontract as a closed door.

"We understand their hesitance to continue working with us at this time, and we hope that they will choose to work with us again sometime in the future," he wrote.

Originally published on Live Science.

To stop an activity, your brain must engage in very precise timing that involves the careful coordination of three distinct areas of the brain, new research has found.

The findings, set to be published on Dec. 20 in the journal Neuron, help explain how people switch tasks once they've already begun them.

The research may help demystify how your brain handles quick decisions like those that happen when you're driving. Imagine you come around the corner, driving the speed limit. Up ahead, a traffic light turns yellow. You're not going to make it, but if you accelerate you can squeeze by just after the light turns red. You decide to put your foot on the gas pedal — but wait! There, in the parking lot, a cop car keeping watch on the intersection. Can you stop your foot in time to avoid getting a ticket for your irresponsible driving?

Certain parts of your brain determine if you'll succeed, the researchers found.

"When we approached this study, we intended to figure out what this one specific area [of the prefrontal cortex region of the brain] was doing," said lead study author Kitty Xu, who was doctoral student at Johns Hopkins University in Baltimore when she did the research. She is now a researcher at Pinterest. [3D Images: Exploring the Human Brain]

But when the study participants had their brains scanned while performing an action-stopping test, the researchers found that at least three brain regions were involved: two parts of the prefrontal cortex, which is an area of the brain involved in planning, as well as the pre-motor cortex, which is an area that's less well-understood.

The one area of the prefrontal cortex that the researchers originally intended to study can be thought of "as a CEO [who] sends out signals to other parts of the brain," which act like managers "who actually do the work," Xu told Live Science.

The timing involved in stopping or failing to stop a motion the brain has already decided to do requires incredibly fast mental work, the study found. A tenth of a second one way or another can mean the difference between speeding through a red light and coming up short. And as people age, the mechanisms that keep the brain making those decisions at top speed break down, and it becomes harder to reverse course, Xu said.

The action-stopping game used in the study was simple, involving starting and stopping eye movements in response to different symbols projected on a screen.

Xu said that she tried the game herself. "It can be frustrating at the beginning when you're first learning, but over time if you are staying alert you can perform this task," she said.

Indeed, the 21 volunteers in the study could learn the game after reading the instructions, but then typically needed a lot of practice to get it right, Xu added.

This wasn't the case for another one of the research subjects: a single macaque monkey, who was also taught to the play the game while the scientists studied the animal's brain. Human brains can be studied only at the macro scale, through magnetic resonance imaging, but a monkey offers researchers the opportunity to (ethically) stick electrodes into living brains to study neurons at work.

The monkey needed a bit more coaxing and to have its head fixed in place so the primate wouldn't destroy the equipment or disrupt the game, Xu said. But "over the time, the monkey learns very well — just as good as humans if not better," Xu said.

Ultimately, the researchers found that the brains of both species of primate tackled the problem of stopping an already-started action in similar ways.

Originally published on Live Science.

If you don't want to think about a fight you had with your sister yesterday, a scary movie you watched recently or the source of that nasty smell on the subway, you're going to need some GABA.

A new, small study suggests that GABA, or gamma-Aminobutyric acid, plays a key role in suppressing unwanted thoughts and memories in a region of the brain called the hippocampus. GABA is a neurotransmitter, or chemical messenger, that's found throughout mammals' central nervous systems.

The new finding offers insight into how humans pull off the daily mental task of squashing down thoughts they don't want to think about, according to the study, which was published Nov. 3 in the journal Nature Communications. The study also provides clues as to what goes wrong in the brains of people with illnesses such as schizophrenia, in which people have trouble suppressing intrusive thoughts, the researchers said. [10 Things You Didn't Know About the Brain]

In the study, the researchers looked at the brains of 24 young, healthy subjects as they tried to suppress or recall memories. They found that the study participants with more GABA in their hippocampi were better at controlling which thoughts and memories popped into their minds compared with the people who had less GABA. And the less GABA that people had in their hippocampus, the less control they wielded over the wild, ceaseless churning of their minds.

But measuring the amount of GABA in a person's brain isn't exactly simple to do.

To do so, the researchers had to get clever: They employed an expensive, somewhat rare technique known as magnetic resonance spectroscopy, or MRS. Though costly and difficult to use, MRS has a key advantage over more typical brain scans: It lets researchers look at not just the general shape and density of subjects' brains but also their specific chemical content. So, with the aid of MRS, the researchers were able to sort their subjects into high-GABA and low-GABA groups.

With the technique to measure GABA levels in place, the scientists then focused on studying the subjects' abilities to suppress thoughts and memories.

Here, the researchers used a simple game. The participants were given a controller with two buttons. They were told to press the left button when certain colors showed up on the screen and the right button when other colors appeared. The participants played this game over and over until they were pressing the correct buttons without thinking about it.

But then the researchers introduced a new rule: Don't press the button if a tone sounds. This made the game much harder; the players had to control their habit of immediately pressing a button, and stop their fingers from flicking forward when the tone played just after a color appeared.

Neuroscientists use this kind of test to measure a person's control over their thoughts and memories. The players who did a better job of avoiding button pressing were assumed to have better control over their remembered impulses.

The study found that the people in the high-GABA group were significantly better at the game than the people in the low-GABA group.

So what does this mean? First, it directly links GABA in the hippocampus to the ability to suppress memories, expanding neuroscientists' understanding of how memory recall works in the brain.

The findings also suggest that mental illnesses such as schizophrenia, which are associated with low levels of GABA, might involve a lack of the basic memory-suppressing chemical tools, the researchers said in a statement.

In people with such mental health conditions, a lack of GABA may be involved in allowing unwanted thoughts and memories to overwhelm the mind, the researchers said. The new study included a small number of young, healthy people, and more research is needed to see if the findings hold up in different groups of people, as well as to better understand how GABA plays a role in memory.

Originally published on Live Science.

The presidential race is really heating up, and some voters are already casting their ballots for Democratic candidate Hillary Clinton or Republican Donald Trump. Given the United States' starkly divided political climate, one might think it obvious that fundamental, built-in differences exist between Democrats and Republicans. 

Science has suggested that there are key features in the brains of liberals and conservatives — bywords, respectively, for Democrats and Republicans these days — that might help explain why people think and vote the way they do.

"There are converging lines of evidence for brain regions that make sense as biological correlates for political attitudes," said Darren Schreiber, a professor of political science at the University of California, San Diego.

Related:

• Election Day 2016: A Guide to When, What, Why and How
• Democratic Party Platform 2016: We Fact-Checked the Science
• Republican Party Platform 2016: We Fact-Checked the Science

Yet ideology stems from more than a slightly oversized or under-functioning brain region, researchers say. One's upbringing and experiences matter a great deal in forming political identities, which after all can change over a lifetime, or even a single election season. [People Become More Liberal With Age]

But some individuals do become quite fixed in their political opinions. Such partisanship might speak to an underlying biological bent to worldviews that events and experience cannot undo.

"Generally people who tend to be moderate can go from one side to another, but I don't know of any extreme left-winger that became a right-winger," said Marco Iacoboni, professor of psychiatry and biobehavioral science at the University of California Los Angeles.  

Ideology, by the numbers

In terms of the percentage of the United States' population that identifies itself as liberal, moderate or conservative, the numbers have held relatively steady over the last 20 years, according to Gallup.

Liberals have remained in the vicinity of 20 percent, moderates, around 37 percent and conservatives a shade higher around 40 percent, since the early 1990s.

At the extremes, those who identify themselves nowadays as hard-left Democrats stands at 9 percent compared with 21 percent who are hard-right Republicans.  

A blue or red brain?

Researchers have long wondered if some people can't help but be an extreme left-winger or right-winger, based on innate biology. To an extent, studies of the brains of self-identified liberals and conservatives have yielded some consistent trends, Schreiber said.

Two of these trends are that liberals tend to have more activity in parts of the brain known as the insula and anterior cingulate cortex. Among other functions, the two regions overlap to an extent by dealing with cognitive conflict, in the insula's case, while the anterior cingulate cortex helps in processing conflicting information. [When did Democrats and Republicans switch platforms?]

Conservatives, on the other hand, have demonstrated more activity in the amygdala, known as the brain's "fear center." "If you see a snake or a picture of a snake, the amygdala will light up — it's a threat detector," said Iacoboni.

A study of British subjects published in 2011 supported these past imaging studies with measurements of brain structure. The study showed that on average the amygdala is bigger in conservatives, likely indicating greater use of it in neurological processing. In contrast, liberals often possessed larger anterior cingulate cortexes.

Altogether, these findings suggest liberals can more easily tolerate uncertainty, which might be reflected in their shades-of-gray policy positions. In the U.S., those typically include being pro-choice and lenient on illegal immigration.

Conservatives, meanwhile, have a more binary view of threats versus non-threats. Again, such a predisposition could be extended to policy positions, such as being pro-life and stricter on the immigration issue.  

Schreiber cautioned, however, that reinforcement of political views might induce the observed phenomena in the brain, rather than the other way around.

Regardless, it is too simple, he said, to chalk up our political ideologies to brain form and function. "The idea that we're somehow hardwired," Schreiber said, in regards to our political ideologies, "is totally inadequate."

Political dynasties

Indeed, genetic and environment studies have suggested that political attitudes are forged more through experience than some innate tendency.

Research in different countries has dovetailed in showing that at most around 40 percent of political ideology is heritable, meaning mom and dad handed it down through their genes, said Schreiber.

While 40 percent is quite significant, it still means that more than half of one's ideological influences come from life as it is lived, and not in the manner of "programmed" traits, such as height or eye color.

Political identify, Schreiber said, is "really clearly not a story of genes or environment but their interaction."

Politicos, since in utero

All these findings suggest that, to a great extent, humans are very much political creatures. Comparative studies with primates, our closest animal relatives, have shown that a driving evolutionary force behind our large brains has been socialization.

Most primates live in big social groups, wherein alliances form and break, often based on sophisticated forms of behavior, including altruism and deceit.

"Evidence really suggests the reason why we have the brain we do as human beings is to solve this problem of politics," Schreiber told LiveScience. "As we have increasingly complex social organization, we need more and more brain mass to deal with its shifting coalitions."

These coalitions include the big political parties themselves. Voters' loyalty to the Dems or the GOP — or neither — is fickle and can change very fast.

In 2015, 29 percent of the U.S. population called themselves Democrats, 26 percent indicated they were Republicans and 42 percent said they were Independents, according to a Gallup survey.

The ebbs and flows make sense, especially over long periods as political parties' positions and the popularity of their prominent members wax and wane. "Politics is constantly changing," said Schreiber. 

In other words, the art (and science) of politicking is far from mastered.

Editor's Note: This article was first published in 2011.

Original article on Live Science.

A wandering mind

Daydreaming sometimes gets a bad reputation: Students who don't pay attention in class end up having trouble completing coursework, and workers who spend meetings thinking about winning the lottery are probably not the most productive. But research has shown that not all daydreaming is bad.

For example, daydreaming motivates people to work toward accomplishing their goals, said Dr. Matthew Lorber, acting director of child and adolescent psychiatry at Lenox Hill Hospital in New York City. For example, if a high school student daydreams about getting into a good college, such daydreaming may motivate him or her to actually study more during high school in order to get into a good college, he said.

Here are a few other surprising facts about daydreaming.

We daydream on purpose

Though people may think of daydreaming as something they do unintentionally, research has suggested that people sometimes zone out on purpose. Moreover, the circumstances in which such intentional mind-wandering occurs may be different from those in which people unintentionally daydream, according to findings published in March 2016 in the journal Psychological Science.

In the study, researchers asked people to complete an easy cognitive task, and found that the participants tended to let their minds wander on purpose and not pay much attention to what they were doing. But when the participants were asked to complete a task that was more challenging and required more focus, the people reported more unintentional mind-wandering, compared with intentional mind- wandering. [10 Things You Didn't Know About You]

The researchers said they think that people intentionally let their minds wander during easy tasks because they know they can get away with not paying attention to what they are doing — it won't hurt their performance. But when they complete a difficult task, they know they need to focus to complete it well, and therefore are less likely to zone out on purpose.

Blinking and thinking

Mind-wandering may go hand in hand with more frequent eye blinking, research suggests. In a study published in 2010 in the journal Psychological Science, researchers asked people to read a passage from a book and tracked their eye movements as they read. The researchers also tracked whether the people's minds wandered at random intervals throughout the experiment, or whether they remained focused. For this part of the study, the researchers asked the people from time to time whether they were paying attention or letting their minds wander away from the task.                                       

They found that people in the study tended to blink more during the moments when their minds wandered, compared with the moments in which they were more focused on the task.

Daydreaming can help with problem-solving

If you are stuck on a problem, letting your mind wander for a bit may help you get unstuck. Research published in 2009 in the journal Proceedings of the National Academy of Sciences (PNAS) suggested that the brain areas that allow people to solve complex problems become more active during daydreaming.

"Mind-wandering is typically associated with negative things like laziness or inattentiveness," lead study author Kalina Christoff, a psychologist at the University of British Columbia, said in a statement. "But this study shows our brains are very active when we daydream – much more active than when we focus on routine tasks."

The findings suggest that daydreaming may serve to distract our attention from immediate tasks to solve other, more important problems, the researchers said. [Pay Attention! 5 Tips for Staying Focused]

Daydreaming amnesia

For some people, letting their mind wander makes it tough to remember what they were doing right before their mind drifted. Research has suggested that such "daydreaming amnesia" is exacerbated if your mind drifts further from your current moment. For example, it's more common when your mind drifts to memories of an overseas trip rather than a staycation, or to a memory of an event that occurred five years ago as opposed to two days ago.

In the study, researchers asked a people to look at lists of words. They then asked some of the people to think about their own homes and where they had been that morning, whereas they asked other people to think about their parents' homes, which they had not visited in several weeks. The researchers then asked all the people in the study to recall as many words from the lists as possible.

The participants who were asked to think about their own homes were able to recall more words, on average, than those in the other group, according to the findings, published in 2010 in the journal Psychological Science.

You can be zapped into a daydream

Zapping a certain brain area may actually increase how often people daydream, according to a study published in 2015 in the journal Proceedings of the National Academy of Sciences. In the study, researchers found that when they stimulated people's frontal lobes with a mild electrical current, the people reported experiencing more daydreams than usual. The frontal lobe is the part of the brain that regulates our self-control, planning and logical thinking.

"Our results go beyond what was achieved in earlier" studies, study co-author Moshe Bar, a neuroscientist at the Multidisciplinary Brain Research Center at Bar-Ilan University in Israel, said in a statement. "They demonstrate that the frontal lobes play a causal role in the production of mind-wandering behavior."

Originally published on Live Science.

Science is powerful, but there is much it can’t explain. And when people see, hear or believe something that is not explained, science finds itself trying to prove things don’t exist, and that’s truly impossible. In the following pages, you’ll learn more about some of the most common inexplicable phenomena — from ghosts to supposed man-like beasts, from incredible experiences at the line between life and death to amazing but unexplained feats of the mind itself. How much of this is real? We’ll let you decide.

Related: Check out the 14 biggest historical mysteries that will probably never be solved.

The Taos Hum

Some residents and visitors in the small city of Taos, New Mexico, have for years been annoyed and puzzled by a mysterious and faint low-frequency hum in the desert air.

Oddly, only about 2 percent of Taos residents report hearing the sound. Some believe it is caused by unusual acoustics; others suspect mass hysteria or some secret, sinister purpose. Whether described as a whir, hum, or buzz and whether psychological, natural, or supernatural no one has yet been able to locate the sound's origin. Thing is, a survey revealed that those who claim to hear the sounds actually hear many different sounds, suggesting the experiences may be subjective, not actually objective sounds (and pretty certainly not one particular sound).

The next item on our list could fill big shoes if it had to. Guess what it is?

Bigfoot

For decades, large, hairy, manlike beasts called Bigfoot have occasionally been reported by eyewitnesses across America. Despite the thousands of Bigfoot that must exist for a breeding population, not a single body has been found. Not one has been killed by a hunter, struck dead by a speeding car, or even died of natural causes. In the absence of hard evidence like teeth or bones, support comes down to eyewitness sightings and ambiguous photos and films.

Since it is logically impossible to prove a universal negative, science will never be able to prove that creatures like Bigfoot and the Loch Ness monster do not exist, and it is possible that these mysterious beasts lurk far from prying eyes. Call us skeptical, and check out our complete story about Bigfoot.

Intuition

Whether we call it gut feelings, a 'sixth sense,' or something else, we have all experienced intuition at one time or another. Of course, gut feelings are often wrong (how many times during aircraft turbulence have you been sure your plane was going down?), but they do seem to be right much of the time. Psychologists note that people subconsciously pick up information about the world around us, leading us to seemingly sense or know information without knowing exactly how or why we know it. But cases of intuition are difficult to prove or study, and psychology may only be part of the answer.

If your intuition is telling you that the next slide is about mysterious disappearances, you're right!

Mysterious Disappearances

People disappear for various reasons. Most are runaways, some succumb to accident, a few are abducted or killed, but most are eventually found. Not so with the truly mysterious disappearances. From the crew of the Marie Celeste to Jimmy Hoffa, Amelia Earhart, and Natalee Holloway, some people seem to have vanished without a trace. When missing persons are found, it is always through police work, confession, or accident never by 'psychic detectives'). But when the evidence is lacking and leads are lost, even police and forensic science can't always solve the crime.

One word about our next slide: Boo!

Ghosts

From the Shakespeare play "MacBeth" to the NBC show "Medium," spirits of the dead have long made an appearance in our culture and folklore. Many people have reported seeing apparitions of both shadowy strangers and departed loved ones. Though definitive proof for the existence of ghosts remains elusive, sincere eyewitnesses continue to report seeing, photographing, and even communicating with ghosts. Ghost investigators hope to one day prove that the dead can contact the living, providing a final answer to the mystery.

Our next mystery is not about ghosts. Our next mystery is not about ghosts. Wait a minute? Haven't I read that before somewhere?

Deja vu

Deja vu is a French phrase meaning 'already seen,' referring to the distinct, puzzling, and mysterious feeling of having experienced a specific set of circumstances before. A woman might walk into a building, for example, in a foreign country she'd never visited, and sense that the setting is eerily and intimately familiar. Some attribute deja vu to psychic experiences or unbidden glimpses of previous lives. As with intuition (see #3), research into ,human psychology can offer more naturalistic explanations, but ultimately the cause and nature of the phenomenon itself remains a mystery. [All About Deja Vu]

The next mystery is really out of this world. Read on!

UFOs

There is no doubt that UFOs (Unidentified Flying Objects) exist — many people see things in the skies that they cannot identify, ranging from aircraft to meteors. Whether or not any of those objects and lights are alien spacecraft is another matter entirely; given the fantastic distances and effort involved in just getting to Earth from across the universe, such a scenario seems unlikely.

Still, while careful investigation has revealed known causes for most sighting reports, some UFO incidents will always remain unexplained. [UFO Sightings & News]

You must check out the next mystery. We're deadly serious.

Related: What are the Marfa Lights?

Near-Death Experiences and Life After Death

People who were once near death have sometimes reported various mystical experiences (such as going into a tunnel and emerging in a light, being reunited with loved ones, a sense of peace, etc.) that may suggest an existence beyond the grave. While such experiences are profound, no one has returned with proof or verifiable information from "beyond the grave."

Skeptics suggest that the experiences are explainable as natural and predictable hallucinations of a traumatized brain. A study of people in cardiac arrest in 2015 found that when the heart is dying, it gets peppered by signals from the brain, which tries to stay active. The scramble of signals might be responsible for near-death experiences, researchers figure.

Two mysteries to go. Can you divine what they might be?

Psychic powers and ESP

Psychic powers and extra-sensory perception (ESP) rank among the top ten unexplained phenomena if for no other reason than that belief in them is so widespread. Many people believe that intuition (see #3) is a form of psychic power, a way of accessing arcane or special knowledge about the world or the future. Researchers have tested people who claim to have psychic powers, though the results under controlled scientific conditions have so far been negative or ambiguous. Some have argued that psychic powers cannot be tested, or for some reason diminish in the presence of skeptics or scientists. If this is true, science will never be able to prove or disprove the existence of psychic powers.

The Body/Mind Connection

Medical science is only beginning to understand the ways in which the mind influences the body. The placebo effect, for example, demonstrates that people can at times cause a relief in medical symptoms or suffering by believing the cures to be effective — whether they actually are or not. Using processes only poorly understood, the body's ability to heal itself is far more amazing than anything modern medicine could create. So while there are many unexplained phenomena, and frankly some of them are dubious, the explainable science of the body and mind, even if we're still trying to figure much of it out, may be among the most amazing phenomena of all.

10 Interesting Facts About Male Brains

Most popular notions about the male brain are based on studies of men ages 18 to 22 — undergrads subjecting themselves to experiments for beer money or course credit. But a man's brain varies tremendously over his life span, quickly contradicting the image of the single-minded sex addict that circulates in mainstream consciousness.

In this presentation, you'll learn about common misconceptions, such as men wanting to sow their wild oats forever. And you'll learn how vulnerable men are to loneliness, and why men are so frustratingly focused on solutions.

In short, gals, here's what you need to know about guys' minds.

Covet wedding bells, too

Women want to settle down, and men want to sow their wild oats forever, the refrain usually goes. But this might be one of the largest misconceptions stemming from the U.S. tendency of using undergrads as test subjects.

Infidelities are most likely to occur before men hit 30, found a study of Bolivian men published in the Proceedings of the Royal Society in 2007. After that, men primarily focus on providing for their families, the study found.

Of course, some men have a harder time with commitment than others — a problem which could be genetic, according to a 2008 study in the Proceedings of the National Academy of Science. Men without the "promiscuity gene," an estimated 60 percent of the population, are more likely to marry. But that's not all. Both they and their wives are also more likely to report relative marital bliss, the researchers found.

Unfortunately, the association is so small, said the study's lead researcher Hasse Walum of the Karolinska Institute in Sweden, "you can't use it for screening potential mates."

Continue to learn why men love a pecking order.

Who's boss?

An unstable hierarchy can cause men considerable anxiety, Brizendine said. But an established chain of command, such as that practiced by the military and many work places, reduces testosterone and curbs male aggression, she said.

Pre-occupation with establishing pecking order, which starts as early as age 6, motivates the "male dance, where they are always putting each other down," Brizendine added. "It is better to be aggressive in a verbal jab than to duke it out," she said.

Keep reading to learn how dad's have hormonal changes, too.

The father-to-be

The male brain becomes especially primed for cooperation in the months before becoming a father. Fathers-to-be go through hormone changes — prolactin goes up, testosterone goes down — which likely encourage paternal behavior, found a 2000 study in Evolution and Human Behavior.

The pheromones of a pregnant woman may waft over to her mate to spur these changes, said Brizendine, who was not involved with the study.

The expecting mom might be repaying a favor: Even before she is pregnant, male pheromones cause good-mom neurons to sprout in the female brain, found a 2008 study published in the journal Hormones and Behavior.

Next slide: Will they ever mature?

The mature male brain

Over the course of evolution, men have needed to compete for status and mates while young and emphasize bonding and cooperation when mature, Mehta said.

Men seem to agree; and psychological studies have shown that one-upmanship holds less appeal for older men. Instead, they pay more attention to relationships and bettering the community, Brizendine said.

The change is likely aided by the slow natural decline in testosterone as a man ages. Mehta and colleagues found that men with high testosterone levels tend to be better at one-on-one competition, while those with lower levels excel at competitions requiring team cooperation. The study was published in the journal Hormones and Behavior in 2009.

Daddy-play

Daddy-specific ways of playing with their kids — more rough-housing, more spontaneity, more teasing — can help kids learn better, be more confidant, and prepare them for the real world, studies have shown. Also, involved dads lessen risky kids' sexual behavior.

Fathers that actively parent tend to have lower testosterone levels, report several cross-cultural studies. While it is not known if the hormone levels cause the behavior or vice versa, researchers theorize that evolution has favored involved dads. Human children are among the neediest of the animal kingdom and good dads optimize the chance that their offspring — and their genes — survive.

Must defend turf

"Part of the male job, evolutionarily-speaking, is to defend turf," Brizendine said. More research is needed in humans but in other male mammals, the "defend my turf" brain area is larger than their female counterparts, she said.

While women too have fits of possessiveness, men are much more likely to become violent when faced with a threat to their love life or territory, she said.

Yeah, No Kidding! See Fight, Fight, Fight: The History of Human Aggression.

Hard-wired to check out women

While often linked to aggression and hostility, testosterone is also the hormone of the libido. And guys have six times the amount surging through their veins as women, said Pranjal Mehta, a social psychologist at Columbia University in New York.

Mehta and colleagues found that testosterone impairs the impulse-control region of the brain. While it has yet to be studied, this may explain why, as Brizendine says, men ogle women as if on "auto-pilot." They often forget about the woman once she is out of their visual field, Brizendine said.

Focused on solutions

While many studies suggest that women are more empathetic than men, Dr. Brizendine stresses this is not entirely true. The empathy system of the male brain does respond when someone is stressed or expressing a problem. But the "fix-it" region quickly takes over.

"This hub does a Google search of the entire brain to come up with a solution," said Brizendine. As a result, men tend to be more concerned with fixing a problem than showing solidarity in feeling, she said.

Check This Out: 10 Things You Didn't Know About the Brain

More vulnerable to loneliness

While loneliness can take a toll on everyone's health and brain, older men seem particularly vulnerable, said Dr. Louann Brizendine, a professor of clinical psychology at the University of California, San Francisco, and author of "The Male Brain" (Broadway, March 2010).

Men tend to reach out less than women, which exacerbates loneliness and the toll it takes on their brains' social circuits, she said.

Living with women may be particularly helpful. Men in stable relationships tend to be healthier, live longer and have hormone levels that may indicate decreased anxiety, studies have shown.

Women might also be good for a guy's gonads. Male mice living with females remained fertile longer than their isolated cousins, found a study published in the Biology of Reproduction in 2009.

More emotional

While females are usually considered the more emotional gender, infant boys are more emotionally reactive and expressive than infant girls, researchers have found.

Adult men have slightly stronger emotional reactions, too — but only before they are aware of their feelings, found a 2008 study published in the Scandinavian Journal of Psychology that closely monitored facial expressions. Once the emotion reaches consciousness, however, men adopt a poker face.

When young, boys likely learn to hide emotions that culture considers "unmanly." But tamping down emotion also spurs the body's "fight or flight" response. A man's strong reaction and subsequent suppression may ready him to handle a threat, theorize the 2008 study researchers at Lund University in Sweden.

This article was originally published on The Conversation. The publication contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

Imagine that Brian promises to drive you to the airport but never shows up, and you miss your flight. When you confront Brian, he tells you that he remembered his promise but decided to watch a movie instead. Would you be angry? You betcha!

But then suppose Brian pleads, “Don’t be angry at me. My brain made me do it. I wanted to watch the movie, and my desires are lodged in my brain. Moreover, I don’t care that much about you, but that is only because my neurons do not fire very fast when I think of you. My brain makes me act as I do, so I’m not responsible.” This plea will not quell your anger. Why not?

Your brain is still you

Brian is correct that his brain made him do it. It was not his legs or eyes that made him watch the movie. If his neurons had been wired differently, then he would have driven you as he promised. It also wasn’t the movie or another person that made him do it. It was his desires, which are in his brain (assuming that minds are not separate substances), so his brain is what caused him to do it.

Nonetheless, what really matters is which part of his brain made him do it. What made him let you down was activation levels in those parts of his brain that constitute Brian’s desires. That fact is just a pseudo-scientific way of saying that he did it because he wanted to. It doesn’t change when he re-describes his desires in terms of brain states.

Critics retort “But he doesn’t control when his neurons fire!” Actually, he does. Brian does not think about his neurons. Nonetheless, if he chooses to watch the movie, then some of his neurons fire — the ones that turn his head toward the movie. And if he chooses not to watch the movie, then other neurons fire — the ones that make his hand reach for the car keys. His desires and choices, thus, do affect what his brain does. Since he — or his desires and choices — controls what he does, the fact that his brain also made him do it is no excuse at all.

Brain blaming doesn’t erase responsibility

Other kinds of brain states do excuse. Imagine that Brianna made the same promise as Brian, but she failed to pick you up only because she had a seizure that left her immobilized. Then Brianna is not responsible, and you should not be angry at her, because her seizure shows you nothing about her or her concern for you. She would not have been able to pick you up no matter how much she valued your welfare and her promise.

These extreme cases are easy. Despite some rhetoric, almost nobody really believes that the fact that your brain made you do it is by itself enough to excuse you from moral responsibility. On the other side, almost everybody agrees that some brain states, such as seizures, do remove moral responsibility. The real issues lie in the middle.

What about mental illnesses? Addictions? Compulsions? Brainwashing? Hypnosis? Tumors? Coercion? Alien hand syndrome? Multiple personality disorder? These cases are all tricky, so philosophers disagree about which people in these conditions are responsible — and why. Nonetheless, these difficult cases do not show that there is no difference between seizures and normal desires, just as twilight does not show that there is no difference between night and day. It is hard to draw a line, but that does not mean that there is no line.

The main problem with a simple slogan like “My brain made me do it” is that it is too abstract. When we talk about the brain in general, people think of some alien force that makes them do what they do not really want — like a seizure. That impression is terribly misleading, but it makes some people react differently to “My brain made me do it” than to “I did it.” Sometimes there is a difference (as in seizures), but sometimes there is no real difference (as with normal desires). Some kinds of activity in our brains are not separate from us — they are us.

What will happen when people get comfortable with talking about brains in this way? They will become less punitive in some cases, such as when a tumor turns a father into a pedophile. However, a better understanding of neuroscience will also keep them from getting fooled by simple excuses like “My brain made me do it.” They will realize that sometimes I do it when my brain makes me do it. That is why their better understanding of neuroscience will not undermine responsibility in general.

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

The World Cup stimulates not only passion and nationalism, but reminiscence. The heroic 2-3 effort of the Socceroos against the Netherlands was the centre of many conversations this week, but will also be remembered for years in the future. My homeland, England’s, World Cup efforts are probably best not being raised in discussion.

Memory for particular events has always fascinated me – why are certain events remembered in more detail than others? Are these specific memories less susceptible to be forgotten over time?

People certainly have stronger memories for events that have an emotional aspect, and memories for sporting events can be particularly robust and vivid. Although you might struggle to recall what you did last weekend, when it comes to sport, particular events can be remembered with incredible precision.

For people suffering from Alzheimer’s disease and dementia, the loss of memories has a devastating impact on their health, well-being and sense of self. As of 2013, there were an estimated 44.4 million people with dementia worldwide. Every week, 1,700 new cases of dementia are diagnosed in Australia. Alzheimer’s disease is the most common form, affecting up to 70% of all people diagnosed with dementia.

Alzheimer’s disease is characterised by damage to the brain in the form of amyloid plaques that form outside neurons, and neurofibrillary tangles made of dysfunctional tau protein inside neurons. This two-pronged attack prevents neurons from communicating with each other effectively across synapses and starves the neurons of nutrients. This results in the death of neurons, leading to loss of brain matter.

With fewer neurons, encoding new memories is less effective. Short-term memory loss is one of the first symptoms of Alzheimer’s disease. Alzheimer’s patients often formulate ways of disguising this kind of memory loss, putting it down to forgetfulness and using memory aids such as making lists. But as the disease progresses to deeper parts of the brain, long-term memory is also lost.

These long-term memories include fundamental knowledge about patient’s past – the names of their close family and significant events such as details of their wedding. The loss of these intrinsic memories not only devastates family members, but creates frustration and distress in Alzheimer’s patients, leading to depression and withdrawal.

The beautiful game

Recently, the project Football Memories in Scotland has shown that discussing soccer with other fans can help stimulate the recollections of some people who suffer from dementia. Soccer is an international sport, uniting communities with shared passion. Sports like soccer act as a thread running through the lives of many people, tying together important events in a fan’s life and connecting them to other enthusiasts.

Using visual cues with dementia patients – such as team photos, can stimulate avid discussion and also stir the recollection of memories that may otherwise be overlooked. Recollected memories are highly detailed – remembering specific matches, goals and incidents. Moreover, these memories contain important information regarding the circumstances and features surrounding the recalled sporting events – locations, time of year, the people you were with and how you were feeling at the time.

For dementia patients, group sessions and one to one discussions with other fans can stimulate extensive discussion and forge friendships across these shared interests. The memories have a robust emotional component and their vivid features provide dementia patients with a sense of empowerment, camaraderie and passion. Also, the recall of specific memories may strengthen the connections between remaining functional neurons (known as neuroplasticity) easing subsequent recall.

Although these projects have not extended to Australia yet, this kind of passionate, image driven discussion can be integrated into conversations by carers of those affected by dementia. These interactions could greatly enhance the sense of self that is lost in those suffering from dementia.

Amy Reichelt does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

Self-driving cars have already arrived, at least in the testing stage, and now mind-controlled flight could be on the horizon, researchers say.

A team of engineers developed an algorithm that can convert brain waves into flight commands. The researchers hope the mind-controlled system paired with specialized airplane controls will make flying easier and safer in the future.

"If flying is more intuitive, it is also easier and thus safer," Tim Fricke, an aerospace engineer at Technische Universität München in Germany, who helped develop the system, told Live Science. "Moderately trained general aviation pilots with [little] flying experience would probably benefit the most from this new approach." [Supersonic! The 10 Fastest Military Airplanes]

During the virtual flying simulations, researchers fitted seven pilots with a white cap covered with dozens of electroencephalography (EEG) cables to record the subjects' brain waves. Each pilot had varying degrees of experience, including one who had never been in an airplane cockpit. The EEG cables sent electrical signals to a computer, which was running the mind-control algorithm; the computer then converted the electric signals into an action that was carried out wirelessly.

Brain waves have distinct patterns, so the algorithm can specifically target the pilots' plane-control thoughts.

Just by thinking commands, the pilots who participated in the experiment were able to complete maneuvers such as takeoffs and landings, and they were able to keep the plane within a few degrees of a given compass direction, the researchers said. The pilots' accuracy surprised the team; if the simulations had been real flights, each of the participants would have passed all the requirements in a pilot license test. Some pilots even landed the plane on the runway in stormy conditions with poor visibility, the researchers said.

However, the mind-control technique has limitations. During flight, pilots rely on the resistance they feel from the physical controls in order to keep the plane on track through clouds and high winds, the researchers said. In mind-controlled flight, the pilots lack this feedback. Researchers need to design a way to signal to the pilots when they are overcorrecting, Fricke said, adding that this could be accomplished by giving the pilots a visual or auditory signal.

The successful simulations do not mean all pilots will suddenly start trading in their captain's hats for EEG caps, the researchers said.

"Brain-computer interface technology is still quite young, and although we might see some amazing developments in the next years, wide application is still decades away, especially when we talk about controlling aircraft, where [the] highest safety standards have to be respected," Fricke said.

Next, the researchers will work on getting the algorithm ready for an unmanned demonstration flight.

The team will present their results, which have not yet been published in a peer-reviewed scientific journal, in September at the German Aerospace Congress (DLRK) in Augsburg, Germany.

Follow Kelly Dickerson on Twitter. Follow us @livescience, Facebook & Google+. Original article on Live Science.

Rats don't usually come out into daylight, especially not on a busy morning in New York City. But there it was, head awkwardly jutting out in front of its body, swinging from side to side. What injured the creature, I have no idea, but its hind legs could no longer support its weight. The rat dragged them like a kid drags a garbage bag that parents have asked be taken out–reluctantly. The muscles in the front legs rippled as they propelled the body forward along the sidewalk. The rodent was surprisingly quick considering the injury. But its aimlessness suggested distress.

Two girls, no more than 15 years old, spotted the wounded rat from about 10 feet away. They held each other close, squealing and giggling, inching toward the animal theatrically. Staring them down, I scowled. How could they not appreciate this creature’s suffering or be touched by its desperation? I looked on, saying nothing.

In The Last Child in the Woods, journalist Richard Louv talks about "nature deficit disorder," something we urbanites have picked up over the last hundred years or so. He says that city-dwellers have become so disconnected from nature that they cannot process the harsh realities of the natural world, like the sight of an injured animal. But if those young women were suffering from urban disconnection, then why didn’t I—a city slicker through and through—react that way as well? What made me respond with empathy instead of disgust?

Evolutionary theorists believe that many of our behaviors are adaptive in some way. "Empathy probably started out as a mechanism to improve maternal care," says Frans de Waal, a primatologist at Emory University and author of The Age of Empathy. "Mammalian mothers who were attentive to their young’s needs were more likely to rear successful offspring."

These offspring were, in turn, more likely to reproduce, so being able to sense another’s feelings was beneficial because it helped mammals to pass on their genes—the ultimate prize in the game of life. Mammalian males also show empathy, de Waal says, because “the mechanism spread from mother-offspring to other relations, including friends."

Although there is still a lot about empathy that scientists do not yet understand, theories abound. From a mechanistic standpoint, some researchers believe that a specific type of neuron—called a “mirror neuron”—might be a key to empathy. These neurons fire both when an individual, carries out an action and when that individual watches another perform the same action. If the theory holds true, mirror neurons might connect us to other living things.

"But apes have mirror neurons too and yet they only do very sporadic empathy, much less than us," says Jonathan Haidt, a social psychologist at New York University.  "So they are only a part of the story."

Some scientists argue that hormones provide the rest of the narrative. And if hormones are the story's main characters, then its hero may be oxytocin—a neurotransmitter that some scientists call the “love hormone.” Researchers have shown that oxytocin, made in the hypothalamus, is involved in human trust, bond formation, generosity and, of course, empathy. One 2010 study, demonstrated that men feel more empathy toward crying children and grieving adults after receiving an aerosol shot of oxytocin compared with a placebo. The science of oxytocin is still in its infancy, however, and although some of the research indicates that the hormone enhances trust and caring, in some cases, it might suppress it.

In addition to the physiological underpinnings of empathy, humans have to be able to imagine another’s situation in order to feel empathy. According to de Waal, this means adding a crucial cognitive layer on top of it all—the “thinking” part of the empathy reaction. This cognitive layer is the reason we held our breath during the Boston marathon bombing as we watched paramedics, runners and law enforcement personnel run to aid the debris-covered victims. It is why we teared up when we saw the bloodstained pavement once the chaos had been cleared away.

In such moments, the benefits of being able to perceive another person's emotions are readily apparent (how else could one comfort a person in need?). But exactly what we humans have to gain from perceiving the pain of non-human animals is less clear-cut.

Pat Shipman, an anthropology professor at Pennsylvania State University and author of The Animal Connection, believes that it all comes down to domestication. “The ability to ‘read’ another species’ emotions underlies all successful domestication of animals,” she says. “If you are going to take a wild animal into captivity, you have to have a tremendous understanding of what that animal needs.” Shipman thinks that those humans who were able to perceive and anticipate the needs of other animals were more successful in keeping them than those who weren't as aware. “Domestication turns us into much more efficient hunters and gatherers. We don’t have to evolve that specific strength, shape or size—we can borrow it from our animal partners instead,” Shipman explains. In short, humans who were more empathetic were also more prosperous. Viewed that way, the girls who squealed at the sight of the injured rat probably wouldn’t have made good hunter-gatherers.

But those girls were not just unsympathetic toward the rat. They were disgusted by it. Could disgust, like empathy, be adaptive?

According to Valerie Curtis, director of the Hygiene Center at the London School of Hygiene and Tropical Medicine, disgust is the voice in our heads that tells us to avoid things—foods and animals—that could harbor “disease-like bodily emanations.” Rats definitely fit that bill.  

The Center for Disease Control and Prevention lists 11 different types of diseases that rodents can transmit to humans, including hantavirus pulmonary syndrome, hemorrhagic fever with renal syndrome and bubonic plague. Breathing dust from places where rats dwell or drinking water in which rodents have defecated are the main modes by which humans contract these illnesses. Of course, bites from infected rats also pose a risk. Researchers think that these diseases explain why humans tend to find rats revolting, but not other rodent species such as hamsters and guinea pigs, which historically have carried less disease. Similarly, when we recoil at the sight of squirming maggots or gag while throwing out rotting food, we are protecting ourselves from the pathogens that they might carry.

These feelings of disgust are evolutionary messages telling us to get as far away as possible from the source of our discomfort. Researchers believe that many areas of the brain participate in the formation of these messages, but the anterior insulae—located deep within a fold of the brain known as the lateral sulcus—are among one of the most important, Curtis says. “They help us monitor our bodies’ interiors and notice nausea.”  

But with conflicting signals from empathy and disgust flooding our brains, how does one emotion prevail over the other? “We are full of conflicting desires, that is the nature of human beings,” Curtis observes.  “At any one time we have to weigh different motives and make a decision what to do based on circumstances, so people may simultaneously want to comfort a sick animal and recoil from its open wound.” What you choose to do, she says, “depends on the strength of your disgust and the strength of your desire to care.”

And when it comes to short-term survival, disgust is often the strongest feeling, Haidt says. We might prefer to think of ourselves as compassionate—a quality that aids long-term survival—but when we find ourselves in potentially life-threatening situations, our immediate desire to keep on living, often expressed through disgust, tends to win out.  

That's why "disgust is much more powerful close up," Haidt says. People might feel a lot of compassion for other creatures in the abstract, but if you show them a sickly animal and ask them to touch it, their empathy won't always translate into action.

On the sidewalk at 9 a.m., I somewhat foolishly expected a crowd to gather around the rat. But the bystanders who weren't rushing to work were rushing to grab coffee at the nearest food-cart. And besides, if people, including me, don’t stop for faltering homeless people on the street, why would they stop for an injured subway rat? It occurred to me that I should spare the creature the agony of a slow death by dehydration, or of a quick one by predation. But what would people think if they saw me killing a rat on Lafayette Street? Would I even be able to stomach it? Sometimes cultural norms supersede even our most primal instincts.

This article was provided by ScientificAmerican.com. Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news. © 2013 ScientificAmerican.com. All rights reserved.

Although people can't directly experience the consciousness of another, they take for granted that other people have minds — that others can think, remember, experience pleasure and feel pain.

People, however, don't typically attribute such minds to robots, corpses and other beings with no apparent consciousness, except if these beings are put in harm's way, new research suggests.

Sympathy for victims

In a series of experiments by Harvard University researchers, people were more likely to ascribe the characteristics of an active mind to non-conscious beings when they were intentionally victimized than when they were unharmed. Examples included a permanently vegetative patient who was starved by a corrupt nurse, a robot that was stabbed by its caretaker, and a corpse that was violated by a mortician.

"People seem to believe that having a mind allows an entity to be part of a moral interaction — to do good and bad things, or to have good and bad things done to them," study researcher Adrian Ward, a psychological scientist at Harvard, said in a statement. "This research suggests that the relationship may actually work the other way around: Minds don't create morality, morality creates minds." [Top 10 Mysteries of the Mind]

In the first experiment, participants read a vignette about "Ann," a permanently vegetative patient who was unresponsive to stimuli, completely dependent on hospital staff to survive, unable to feel pain and not expected to recover. One group of participants read a version of the story in which Ann was properly taken care of by her nurse. In the darker version of the story, the nurse intentionally unplugged Ann's food supply each night, hoping her patient would eventually starve so that the nurse could collect cash promised to her by a distant relative named in Ann's will.

Both groups of participants were asked to gauge the level of Ann's awareness, capacity for agency and ability to feel pain — all adding up to a general measure of mind attribution. Those who read that Ann was starved tended to attribute more mind to her than those who read that she was unharmed, the researchers found.

The same pattern was true for participants who read two different versions of a story about "George," a highly complex social robot. Those who read that George was routinely jabbed in his sensors with a scalpel thought the robot had more consciousness than those who read a version in which George was not a target for harm by his human caretaker.

Humanization vs. dehumanization

The findings could help explain why there is fierce disagreement on issues like abortion, assisted suicide and animal rights; a person's moral standing could greatly influence how they view the capacity for thinking, feeling pain and consciousness in a fetus, a comatose patient, or a lab rat, the study suggests.

"When these entities are thought of in moral terms, they're attributed more mind," Ward said in a statement. "It seems that people have the sense that something wrong is happening, so someone must be there to receive that wrong."

Meanwhile, when a fully conscious adult human becomes the victim of wrongdoing, he or she is attributed less mind, Ward and colleagues found, which is consistent with previous research on victim dehumanization. A set of participants who read a story about "Sharon," a woman physically abused by her boss, saw her as less able to experience pain and less aware than those who read a story about Sharon and her boss that involved no abuse.

While beings that have a mind to begin with are dehumanized through victimization, entities with absent or limited consciousness gain minds by being harmed, the researchers say. The researchers added a worthwhile avenue of study may be to investigate the threshold between these two opposing effects, where people stop humanizing victims and begin to dehumanize them.

 Their findings were detailed this month in the journal Psychological Science.

Follow Megan Gannon on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.

Editor's Note: With the release of the latest edition of the mental health manual, the Diagnostic and Statistical Manual of Mental Disorders (the DSM), LiveScience takes a close look at some of the disorders it defines. This series asks the fundamental question: What is normal, and what is not?

Angry kids who throw excessive, explosive tantrums now have their own disorder: disruptive mood dysregulation disorder.

Whereas this new addition to the mental health dictionary, the DSM, has prompted protests that psychiatrists are turning a normal part of childhood into a mental disorder, proponents say it will address the skyrocketing rate of another diagnosis that is leading to the inappropriate use of powerful medications on children.

The soaring diagnoses belong to pediatric cases of bipolar disorder.

Between 1994-1995 and 2002-2003, the diagnosis of bipolar disorder in children grew by 40-fold, according to research published in 2007 in the journal Archives of General Psychiatry. [11 New Warning Signs Help Spot Mental Illness in Children]

Many of these children exhibited a pattern not consistent with a bipolar diagnosis. Specifically, bipolar disorder involves episodes of mania, which can show up in children as irritability. However, many of the children diagnosed did not have clear-cut episodes of irritability, instead, they were constantly irritable. As a result, experts believe many children are being misdiagnosed.

Bipolar disorder is often treated with medications that bring worrisome side effects that are worse in children, according to the advocacy group the National Alliance on Mental Illness. These include weight gain that brings increased risk of diabetes or heart problems later in life, movement abnormalities and other problems.

When it came time to put together the new edition of the mental health manual, called the DSM-5, officials at the American Psychiatric Association, which publishes the manual, wanted to include a better-fitting diagnosis for kids with persistently angry, irritable dispositions, hence the addition of disruptive mood dysregulation disorder (DMDD).

However, the addition is controversial. Allen Frances, who chaired the task force for the previous edition of DSM, charges that this new DMDD diagnosis "will exacerbate, not relieve, the already excessive and inappropriate use of medicationin young children."

The addition of DMDD could prove helpful, because it will enable researchers to study these symptoms in children who have previously been diagnosed with bipolar disorder, but who don’t fit the profile for that disorder, said Robin Rosenberg, a clinical psychologist and co-author of the psychology textbook "Abnormal Psychology" (Worth Publishers, 2009).

"The concern is that it will lower the threshold for diagnosing kids who are just having a hard time," Rosenberg said. "There is a gain and there is a risk. If it becomes overly diagnosed, it will prevent us from figuring out what is going on with kids who really have this persistent problem with mood and behavior and, more importantly, needlessly put children on dangerous medications."

Tantrums and bad moods are normal parts of childhood. But to receive a DMDD diagnosis, a child must have rages that are "grossly out of proportion" three or more times per week, on average. The child's mood between outbursts must be "irritable or angry most of the day, nearly every day," according to the DMDD criteria, which set a threshold of at least 12 months.

Kids who might qualify for this new diagnosis may come to the attention of mental health professionals because they have serious behavioral trouble at school or their parents may be unable to control them at home, Rosenberg said.

Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.

Editor's Note: In this weekly series, LiveScience explores how technology drives scientific exploration and discovery.

Human experience is defined by the brain, yet much about this 3-lb. organ remains a mystery. Even so, from brain imaging to brain-computer interfaces, scientists have made impressive strides in developing technologies to peer inside the mind.

Imaging the brain

Currently, scientists who study the brain can look at its structure or its function. In structural imaging, machines take snapshots of the brain's large-scale anatomy that can be used to diagnose tumors or blood clots, for example. Functional imaging provides a dynamic view of the brain, showing which areas are active during thinking and perception.

Structural-imaging techniques include CAT scans, or computerized axial tomography, which takes images of slices through the brain by beaming X-rays at the head from many different angles. CAT, or CT, scans are often used to diagnose a brain injury, for example. Another method, positron emission tomography (PET), generates both 2D and 3D images of the brain: A radioactively labeled chemical injected into the blood emits gamma rays that a scanner detects. And magnetic resonance imaging (MRI) provides a view of the brain's overall structure by measuring the magnetic spin of atoms inside a strong magnetic field.

"There's no question that MRI is probably the best way to see the brain," said Dr. Mauricio Castillo, a radiologist at the University of North Carolina at Chapel Hill and editor-in-chief of the American Journal of Neuroradiology.

In the realm of functional imaging, the current gold standard is functional MRI (fMRI). This technique measures changes in blood flow to different brain areas as a proxy for which areas are active when someone performs a task like reading a word or viewing a picture. [Inside the Brain: A Photo Journey Through Time]

"The emphasis nowadays is to try to merge how the brain is wired with the activation of the cortex [the brain's outermost layer]," Castillo said.

Several methods can be combined to merge brain structure and function. For example, MRI and PET scanning can be performed simultaneously, and the images can be combined to show physiological activity superimposed on an anatomical map of the brain. The end result can be used to tell a surgeon the location of a brain lesion so it can be removed, Castillo said.

Recently, a new technique has been developed to literally see inside the brain. Called CLARITY (originally for Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/Immunostaining/In situ hybridization-compatible Tissue-hYdrogel), it can make a (nonliving) brain transparent to light while keeping its structure intact. The technique has already been used to visualize the neurological wiring of an adult mouse brain.

Decoding thoughts

Some scientists want to see inside the brain more figuratively. Enter brain-computer interfaces (BCIs or BMIs, brain-machine interfaces), devices that connect brain signals to an external device, such as a computer or prosthetic limb. BCIs range from noninvasive systems that consist of electrodes placed on the scalp, to more invasive ones that require the electrodes to be implanted in the brain itself.

Noninvasive BCIs include scalp-based electroencephalography (EEG), which records the activity of many neurons over large brain areas. The advantage of EEG-based systems is that they don't require surgery. On the other hand, these systems can only detect generalized brain activity, so the user must focus his or her thoughts on just a single task.

More invasive systems include electrocorticography (ECoG), in which electrodes are implanted on the surface of the brain to record EEG signals from the cortex. Since Wilder Penfield and Herbert Jasper pioneered the technique in the early 1950s, it has been used, among other purposes, to identify brain regions where epileptic seizures begin.

Some BCIs use electrodes implanted inside the brain's cortex. Although these systems are more invasive, they have much better resolution and can pick up the signals sent by individual neurons. BCIs can now even allow humans with paraplegia (paralysis of all four limbs) to control a robotic arm through thought alone, or allow users to spell out words on a computer screen using just their mind.

Despite many advances, a lot remains unknown about the brain. To bridge this gap, American scientists are embarking on a new project to map the human brain, announced by President Barack Obama in April, called the BRAIN initiative (Brain Research through Advancing Innovative Neurotechnologies).

But neuroscientists have their work cut out for them. "The brain is probably the most complex machine in the universe," Castillo said. "We're still a long way from understanding it."

Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

Editor's Note: With the release of the latest edition of the mental health manual, the Diagnostic and Statistical Manual of Mental Disorders (the DSM), LiveScience takes a close look at some of the disorders it defines. This series asks the fundamental question: What is normal, and what is not?

The latest edition of the mental health manual used by psychiatrists to diagnose disorders reveals a change in thinking on gender identity. The perspective change is similar to a decision made in 1973, when the American Psychiatric Association eliminated homosexuality from its disorders' list.

In the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), released on May 22, the now-defunct diagnosis of gender identity disorder (GID) receives a new name, gender dysphoria, which reflects a new emphasis.

Both GID and gender dysphoria describe a condition in which someone is intensely uncomfortable with their biological gender and strongly identifies with, and wants to be, the opposite gender. Some of these people may live as their desired gender, and may even seek gender reassignment surgery that can allow them to trade, for example, a penis for a clitoris and a scrotum for a vagina. [5 Surprising Facts About Gay Conversion Therapy]

In the old DSM-IV, GID focused on the "identity" issue — namely, the incongruity between someone’s birth gender and the gender with which he or she identifies. While this incongruity is still crucial to gender dysphoria, the drafters of the new DSM-5 wanted to emphasize the importance of distress about the incongruity for a diagnosis. (The DSM-5 uses the term gender rather than sex to allow for those born with both male and female genitalia to have the condition.)

This shift reflects recognition that the disagreement between birth gender and identity may not necessarily be pathological if it does not cause the individual distress, said Robin Rosenberg, a clinical psychologist and co-author of the psychology textbook "Abnormal Psychology" (Worth Publishers, 2009). For instance, many transgender people — those who identify with a gender different than the one they were assigned at birth — are not distressed by their cross-gender identification and should not be diagnosed with gender dysphoria, Rosenberg said.

Transgender people and their allies have pointed out that distress in gender dysphoria is not an inherent part of being transgender. This sets it apart from many other disorders in the DSM, because if someone is depressed, for example, he or she is, almost by definition, distressed as part of depression. In contrast, the distress that accompanies gender dysphoria arises as a result of a culture that stigmatizes people who do not conform to gender norms, Rosenberg said.

In this regard, the change resembles the elimination of homosexuality from the manual 40 years ago.

"The concept underlying eliminating homosexuality from the DSM was recognizing that you can be homosexual and psychological healthy or be homosexual and psychologically screwed up. Being homosexual didn’t have to be the issue," Rosenberg said. 

The DSM-5 also separates the diagnosis of gender dysphoria for children from that of adolescents and adults. The characteristics of gender dysphoria vary with age, and many children with gender dysphoria outgrow it as they age, the manual notes.

Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.

NEW YORK — As you read this sentence, the millions of neurons in your brain are frantically whispering to each other, resulting in the experience of conscious awareness.

The nature of consciousness has intrigued philosophers and scientists for thousands of years. But can modern neuroscience ever hope to crack this mysterious phenomenon? At the World Science Festival, an annual celebration and exploration of science held here in New York, a panel of experts debated what scientists can and can't learn about the mind by studying the brain.

Philosophy of the mind

Plenty of great minds have pondered the meaning of consciousness over the ages, said philosopher Colin McGinn of the University of Miami. The 17th-century French mathematician and philosopher René Descartes famously introduced the notion of mind-body dualism, which holds that the world of the body is fundamentally separate from the world of the mind, or soul, although the two may interact. In the 19th century, the English biologist Thomas Huxley helped develop the theory of epiphenomenalism, the idea that physical events in the brain give rise to mental phenomena. On the panel, McGinn also talked about panpsychism, the view that the universe is made of minds. [Watch a replay of the program here]

McGinn himself believes that no matter how much scientists study the brain, the mind is fundamentally incapable of comprehending itself. "We're rather like Neanderthals trying to understand astronomy or Shakespeare," McGinn said. Human brains suffer from a "cognitive gap" in understanding their own consciousness, he said.

Panelist Christof Koch, a neuroscientist and chief scientific officer at the Allen Institute for Brain Science in Seattle, took issue with McGinn's view. "I think it's a defeatist argument," Koch said. His rebuttal was as colorful as his outfit — a flamboyant Hawaiian shirt and orange pants. "Historically, philosophers have a disastrous record of explaining things," Koch said. Philosophers are very good at asking questions, he said, but not so good at finding satisfactory answers.

Searching for answers

Koch and the other members of the panel turn to scientific experiments to find answers. For example, the so-called mirror test, developed by psychologist Gordon Gallup in 1970, is a test of self-awareness in babies and animals. A colored dot is placed on the face of a baby or an animal subject positioned in front of a mirror. If the subject recognizes that the dot in the mirror is the same as the one on its own body, it is said to be self-aware. Babies show self-awareness after about 8 months of age. Animals such as chimpanzees, dolphins and even octopi show it, too. [That's Incredible! 9 Brainy Baby Abilities]

Koch's own work focuses on how the activity of the brain's neurons gives rise to conscious experience. In one well-known experiment, Koch and colleagues discovered that individual neurons can encode abstract concepts, such as a family member or celebrity. They even found so-called Jennifer Aniston neurons that were active only when a person saw an image of the actress. The conscious experience is of course much more complex than the activity of single neurons, but scientists can learn a lot from the ways in which these brain cells behave and are connected, Koch explained.

Panelist Nicholas Schiff, a neurologist at Weill Cornell Medical College in New York, talked about his work with people recovering from a coma, at the border between consciousness and unconsciousness. "Consciousness is a very graded phenomena," Schiff said. When a person wakes up, for example, he or she is not fully conscious, but gains awareness gradually.

Schiff went on to describe the remarkable case of a man named Donald Herbert, a firefighter who suffered a traumatic brain injury when the roof of a burning house collapsed on him, depriving him of oxygen for several minutes. The accident left Herbert blind and in a minimally conscious state for nine years. One day, his doctor gave him drugs used to treat Parkinson's disease and other brain disorders, and Herbert woke up. He retained his memory and immediately started speaking to his friends and family.

The panelists contrasted Herbert's condition to that of Terri Schiavo, a woman who was in a "persistent vegetative state" from 1990 to 2005 and became the center of a legal battle over the decision to withdraw life support. Schiavo's case was completely different from Herbert's, Schiff said, because Schiavo's brain had been extensively monitored and no signs of brain activity were found in areas associated with consciousness.

Weighing in on the discussion, panelist Mélanie Boly, a neurologist at the Belgian National Fund for Scientific Research and at the University of Wisconsin-Madison, described her work with coma patients. Boly's research aims to chart the brain activity of coma patients on the path to death or recovery. Boly also talked about a realm of consciousness all people are familiar with — sleep. By magnetically stimulating parts of the brain while people are sleeping, Boly has shown that brain activity is much more localized and less complex during sleep than during waking.

The panelists all agreed that the brain gives rise to conscious phenomena. As Koch wittily put it, "No brain, never mind!" But in contrast to McGinn's view that the mind is inherently unknowable, the others believe the subject is increasingly accessible to scientific study. Whereas McGinn admitted he finds the conundrum of consciousness frustrating, the others find it uplifting.

"I think it's so inspiring to be in [this] great time where so many things are happening, so much knowledge is gained, and later on, we hope to be able to address such deep questions for human life," Boly said.

Editor's Note: This article was updated on June 3, 2013, to correct a typo in when Terri Schiavo entered a persistent vegitative state (1990, not 1900, as previously stated).

Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science .

The strength of the bond between a toddler and his mother influences his likelihood of becoming obese as a teen, a new study says.

The obesity rate was more than twice as high among teens who in early childhood had poor-quality relationships with their mothers, compared with those with better relationships.

The researchers said their work suggests that areas of the brain that control emotions and responses to stress, as well as appetite and energy balance, work together to influence the likelihood that a child will be obese. Moreover, obesity-prevention efforts should include strategies to improve the mother-child bond, they said.

The study does not support that idea that mothers are to blame for children's obesity, the researchers said. Instead, "Societally, we need to think about how we can support better-quality maternal-child relationships because that could have an impact on child health," said study researcher Sarah Anderson, assistant professor of epidemiology at Ohio State University.

The findings were published online Monday (Dec. 26) in the journal Pediatrics.

Growing bonds

The researchers analyzed data from nearly 1,000 children from nine states who had taken part in the Study of Early Child Care and Youth Development, which is a long-term study of children born in 1991. Kids were considered to be obese teenagers if at age 15 their body mass index (BMI) was among the highest 5 percent of children.

The researchers had assessed the bonds between the children and their mothers when the kids were 15-months old, 2-years old and 3-years old by watching 15-minute play sessions, and also observing the children's reactions to being briefly separated from their mothers.

The findings showed that the lower the quality of the relationship in terms of the child's emotional security and the mother's sensitivity, the higher the risk that a child would be obese at age 15 years.

The researchers rated 241 children as having a poor-quality maternal-child relationship during early childhood, and 26.1 percent of these children became obese teenagers. Among those with the highest quality relationships, the obesity rate was 13 percent.

"It is possible that childhood obesity could be influenced by interventions that try to improve the emotional bonds between mothers and children rather than focusing only on children's food intake and activity," Anderson said.

The association between early childhood experiences and teen obesity has origins in the brain, according to the study.

"Animal studies have shown that stress preferentially increasesconsumption of highly palatable foods, and eating these foods acts to calm the stress-perceiving areas of the brain," the researchers wrote in their study.

"Sensitive parenting increases the likelihood that a child will have a secure pattern of attachment and develop a healthy response to stress," Anderson said. A child's response to stress response can influence how well she sleeps and whether she eats in response to emotional distress.

Previous studies have shown that children's level of physical activity, diet, rate of maturation and the BMIs of their parents also influence their risk of obesity.

What can parents do?

Psychologists describe securely attached children as those who rely on their parents as a "safe haven," which allows them to explore their environments freely, adapt easily to new people and be comforted in stressful situations, according to the researchers. Toddlers who are insecurely attached tend to have experienced negative or unpredictable parenting and may respond to stress with extreme anger, fear or anxiety, or avoid or refuse interactions with others.

Parents help their children develop a healthy response to stress by protecting children from extreme levels of stress, responding supportively and consistently to normal levels of stress, and modeling behavioral responses to stress, according to the researchers.

"Interventions are effective in increasing maternal sensitivity and enhancing young children's ability to regulate their emotions, but the effect of these interventions on children's obesity risk is not known, and we think it would be worth investigating," Anderson said.

Pass it on: A healthy bond with parents can reduce children's stress levels and lower their chances of later becoming obese.

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Adding to mounting evidence that the effects of prematurity last well beyond infancy, a new study suggests that babies born at very low birth weights are more likely to suffer from memory and attention problems, at least into early adulthood, than peers born at low or normal weights.

Study participants born at very low weights scored an average of eight points lower on IQ tests and did significantly worse on tests measuring "executive function" skills, such as attention, visual and working memory, and ability to understand words, the study showed.

"We were not surprised," said study author Katri Raikkonen, a professor of psychology at the University of Helsinki in Finland. "Previous reports in children and adolescents born prematurely have reported results in line with ours. Our study offers a longer term follow-up and shows that these differences persist into young adulthood – when the brain-maturation process is ending."

The practical impact of such deficits – including organization problems, distraction and trouble focusing – can extend through a person's schooling and negatively affect career and economic success, said Dr. Robin Smith, of Cohen Children's Medical Center in New Hyde Park, N.Y.

IQ and education

The study participants were between 21-and-30-years old; a group of 103 participants weighed less than 3.3 lbs. (1.5 kilograms) at birth, a second group of 105 participants weighed more than 3.3 lbs. at birth and were born after full-term pregnancies (births after the 37th week of pregnancy are considered full-term).

Smith said that an 8-point difference in IQ can be significant, necessitating tutoring or other interventions to overcome the disadvantage.

Those born at very low weights were more likely to have received remedial education while in school, the study found, though there were no differences in their self-reported academic performance.

"What's important about this study is recognizing that these problems in childhood don't end at the end of childhood," Smith said. "These newborns are at high risk, but we need to look beyond that," he told MyHealthNewsDaily. "Many physicians who treat these adults are either unaware or untrained in these issues."

For preemies, early-intervention measures such as physical and occupational therapy and extra academic help can provide a "protective effect" from cognitive deficits, Smith said, as well as offset the loss of IQ points.

Not all preemies

Despite the findings, Raikkonen said, it's important to note that not all preemies with very low birth weights will experience these effects.

"There are still large individual differences," she said. "Some preemies fare better and others worse – which of course is the case for term-born infants as well."

While the research underscores the need to extend pregnancy as long as possible, Raikkonen and Smith said, it should also raise awareness that the dangers of prematurity have long-lasting effects.

"There are many reasons why we would want extend the time in utero, but [another] issue is making sure these children are identified as high-risk infants and children . . . and to make sure as they get into young adulthood that the issues are addressed," Smith said. "I think it's a given that to prevent a lot of the problems of prematurity, we want keep fetuses in utero as long as possible."

The study will be published tomorrow (Dec. 6) in the journal Neurology.

Pass it on: Children who had low weights at birth may benefit from physical therapy and extra academic help in school.

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Question: My husband told me he has no energy to do chores around the house because he's suffering from male menopause. He's a very funny guy.

Answer: Your husband was obviously trying to yank your chain, but there's some truth in his joking. Fatigue is a common symptom of male menopause, also known as andropause (andro means male).

Both andropause and male menopause are used to describe decreasing levels of the male hormone testosterone that come with aging. Most men see testosterone levels drop as they get older. Some have described andropause as puberty in reverse.

Age-related decline in testosterone levels is also called testosterone deficiency, androgen decline in the aging male (ADAM) or late onset hypogonadism (LOH).

Andropause is different from the menopause women experience. In menopause, the production of female hormone drops suddenly. In men, there's a gradual decline in hormone levels.

When men reach about 40, testosterone levels usually begin to drop about one percent a year. The reduction is rarely noticeable in men younger than 60. By the time men reach their 80s, about half have low testosterone.

Young men often have testosterone levels exceeding 1000 nanograms per deciliter (ng/dl). The average testosterone level in 80 year-old men is 200 ng/dl.

Some men maintain normal testosterone levels into old age. And there are men with low testosterone levels who have no symptoms. The only sure way to learn if you are low on testosterone is by taking a blood test.

The following are some symptoms of low testosterone: diminished sex drive, reduced muscle bulk and strength, night sweats, infertility, fewer spontaneous erections, depression, loss of body hair, swollen breasts, palpitations, shrunken testes, height loss, fatigue, irritability, reduced self-confidence, poor concentration, memory loss, sleep problems, increased body fat and anemia.

It is normal for erections to occur less frequently in older men than in younger men.

However, erectile dysfunction (ED) is usually brought on by medical or psychological causes, not simple aging. About 90 percent of ED is believed have medical origins such as drugs taken to treat high blood pressure.

Here are some recommendations to deal with andropause:

• See your doctor for a check-up. Discuss symptoms, medications you are taking, treatment options and lifestyle changes.
• Many older men suffer from undiagnosed depression. Depression in men can be more than feeling down. Depressed men can be irritable and withdrawn. They often work too much, drink to excess and try to get thrills from taking risks. If you think you might be depressed, get help.
• Regular exercise helps physically, mentally and emotionally.
• Eat a healthy diet.

Testosterone replacement therapy (TRT) is the primary treatment for declining levels of testosterone, but it is enveloped in controversy. It has helped some men, but TRT has risks, especially for men with prostate cancer and heart disease. And, TRT may not improve symptoms. More studies need to be done to determine the safety and efficacy of TRT.

There are claims that herbal supplements can relieve symptoms. Not one of these supplements has been proven to be safe and effective for age-related low testosterone.

If you would like to read more columns, you can order a copy of "How to be a Healthy Geezer" at www.healthygeezer.com .

All rights reserved © 2011 by Fred Cicetti

More from the Healthy Geezer:

A rare condition may help researchers understand the origins of laugher in the brain, a new study says.

The study involved patients with gelastic epilepsy, an uncommon condition characterized by seizures that manifest as uncontrollable laughing spells. Researchers knew patients with this condition have lesions in an area of the brain called the hypothalamus. The new study pinpointed these lesions in a specific region in the back of the hypothalamus.

By honing in on a precise region, the researchers said they hope to get a better idea of what parts of the brain are involved in laughing, which may be possible to ascertain by looking at the parts of the brain that are connected to this specific region of the hypothalamus.

"It's almost like a big city," said study researcher Josef Parvizi, an assistant professor of neurology at Stanford University."We want to know exactly which district in the city is involved," Parvizi said. "It tells us exactly where to look for the network of laughter."

Parvizi and colleagues reviewed brain imaging information from 100 patients with gelastic epilepsy. Because the condition is so rare, ahe study of this size was hard to achieve, Parvizi said.

In every case, the patient's brain lesions were centered in an area of the hypothalamus called the mammillary bodies. The findings suggest laughing involves the mammillary bodies and areas connected to them.

The researchers also found that the longer patients had had their seizures, the more likely they were to have a more severe form of gelastic epilepsy, in which patients develop additional types of seizures in addition to laughing seizures.

Gelastic epilepsy usually begins at age 3 or 4, according to Epilepsy Action, an epilepsy advocacy organization in the United Kingdom. The study suggests "if you let patients go untreated, the child's seizures will get worse," Parvizi said. "The sooner you stop it, the better it is."

The laughter in gelastic epilepsy usually occurs suddenly and is out of place, according to Epilepsy Action. The laughter is often abnormal, and usually described as being "hollow," "empty" and not very pleasant, Epilepsy Action says.

The new study was presented Sunday (Dec. 4) at the American Epilepsy Society meeting in Baltimore.

Pass it on: A region of the brain's hypothalamus may be involved in human laughter. 

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As we're smack dab in the middle of the holiday season, I thought it would be a good time to talk about eating not because you're hungry, but because you're under stress. This is one time of year when pressures are high and food is abundant – a potential recipe for dietary disaster.

I've always found that I eat more during the holidays for two reasons: One, there's plenty of tempting food all around, and two, there's usually a little extra pressure from one source or another. It could be from family drama, work or just the pressure that comes along with entertaining. The source doesn't really matter — when the stakes are high, the cookies start calling my name.

Although there's a little comfort in knowing that I'm not the only one who succumbs to stress eating from time to time, it's not a healthy habit. According to 2007 research published in the journal Nutrition, stress induced eating is one likely factor that contributes to obesity.

But in any case, eating isn't a good way to deal with stress. Around the holidays, it can be helpful to create an action plan for dealing with stress.

Here's what my plan looks like:

1. Set the alarm to a peaceful tone to wake you up gently. That feeling you get when the alarm buzzer blazes through the morning silence is a form of stress. Why would you want to start your day that way?
2. In the weeks leading up to the holiday season, start cutting back on carbs. If you choose a white-flour bagel for breakfast, the refined flour will cause an inevitable spike in your blood sugar, which causes unnecessary stress to your system. Opt for whole wheat instead.
3. Drink a lot of water and other non-caffeinated beverages. When the stress does come on, you'll be better suited to handle it than if you guzzle down the coffee.
4. Take a cat nap to lower your stress level during the day. If you feel like your day is spiraling out of control, it's ok to check out for a little while and regroup. Just remember to set a gentle alarm to wake you in about 15 minutes. This way, you won't miss out on anything that could cause stress later.
5. If a catnap isn't an option, try going for a walk or a bike ride. When you exercise, your body releases endorphins that can trigger positive feelings and help combat feelings of stress. 

Healthy Bites appears on MyHealthNewsDaily on Wednesdays. Deborah Herlax Enos is a certified nutritionist and a health coach and weight loss expert in the Seattle area with more than 20 years of experience. Read more tips on her blog, Health in a Hurry!

Who among us hasn't approached New Year's – at least once – pledging to lose weight? 'Tis the season for resolutions, whether it's to drop pounds, stop smoking, work less (or more), or clear the clutter from our homes.

But laudable as it may be, setting specific goals isn't the way to go, experts say. For a better shot at succeeding, we need instead to change our habits – defined as recurrent, often unconscious patterns of behavior that we frequently repeat.

"It's definitely better to create what I call process goals, rather than outcome goals," said Art Markman, a professor of psychology and marketing at University of Texas at Austin and author of the upcoming book, "Smart Thinking: Three Essential Keys to Solve Problems, Innovate and Get Things Done" (Penguin Group, 2012.

"We're better off saying, 'I'm going to exercise every Tuesday and Thursday at 4 p.m. at the gym up the street' than, 'I'm going to lose 20 pounds,'" Markman said. "The goal of losing 20 pounds is too abstract to carry out – if we knew how to do that, we would have done it already."

But habits – by their very definition – aren't easily altered, and moreover, most don't need to be because they serve important functions, said Ian Newby-Clark, an associate professor of psychology at the University of Guelph in Ontario.

"They become automatic or semi-automatic over time because they're done again and again – giving you pleasure, helping you avoid something disagreeable or minimizing thinking about routine tasks – like eating breakfast in the morning," Newby-Clark said. "For that reason alone, they're going to be tough to change."

Markman and Newby-Clark offered these tips to help modify your life, one habit at a time:

1. Know thyself

If you're aware you eat too much after stressful conversations, or crave cigarettes at certain points of the day, then you've got a head start at turning those hankerings around. "It's important to understand your triggers for the habit," Markman said. "You need to know what you're actually planning for."

He suggested spending two weeks generating a "habit diary," which could be a notebook or smartphone app where you record your thoughts and feelings each time you notice behaviors relating to a habit you'd like to adjust. "Don't try to change things yet, just understand what you're doing," he advised, "because you're making mindless things mindful."

2. Start small

Just as Rome wasn't built in a day, years of poor lifestyle choices can't be torn asunder all at once. Don't promise yourself you'll exercise five days a week when twice is much more realistic, Newby-Clark said, and don't pledge to wake up an hour earlier each morning when 15 minutes seems eminently more doable.

He suggested making "mini-plans" – dubbed "implementation intentions" by research psychologists – that breakdown objectives into simple, almost brainless actions. "Simply telling yourself, 'When I wake up in the morning, I will grab my gym bag,' or 'When I see the fridge, I will open it to prepare a healthy meal' makes a world of difference, and makes it much more likely you will do the behavior," Newby-Clark said.

3. Don't replace something with nothing

The hardest goals to fulfill are negative, such as eating less or quitting smoking or drinking, Markman said. That's because these efforts center on replacing something – food, tobacco or alcohol, for example – with nothing.

"Habits are part of memory – taking parts of your world and converting them into motivation to act," he said. "You can't stop your memory from working, so instead you need to reprogram it by replacing something with something else." That means eating differently rather than eating less, Markman said, or drinking club soda instead of liquor at parties. The need will still exist – just find a healthier replacement.

4. Plan to fail

Just as it's crucial to visualize success, it's also necessary to plan to fail, Markman said. Confused? It's not that you can't expect to succeed with steady effort, but you will inevitably stumble at some point in the process – and you must prepare so that won't spell the end of your efforts.

"What can go wrong?" he asked. "If you suddenly find yourself at a party with a ton of food around, what are you going to do? Eat a little in advance so you're not starving and everything doesn't leap off the buffet table and onto your plate. Whatever it is, have a plan."

5. Be kind to yourself

When slip-ups do occur, try to keep the bigger picture in mind. Too many people cheat on their diets, for example, and decide that a single mistake has doomed the entire plan – a phenomenon Markman said is known as the "what-the-hell effect" (as in, "What the hell, now that I've eaten that cupcake I may as well eat two more.")

"We've all failed at these things, so we know it's not easy," he said. "There will be times we eat too much . . . but rather than consider that to be a failure overall, we need to realize it's just one day where things didn't go the way we wanted them to. Try to learn from it, but tomorrow's another day."

Pass it on: Our resolutions to be healthier are more likely to be successful if we focus on changing our habits.

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The deadly brain diseases known as prion diseases might pass from one species to another more easily than previously thought, a new study from France finds.

Prions, such as those that cause "mad cow" disease, spread via exposure to infected lymphoid tissues -- such as the spleen or lymph nodes -- more easily than they can through exposure to infected brain tissues, the study showed.

The finding suggests that the number of animals or people that are "silent carriers" of prion diseases may be higher than previously thought.

Unlike diseases caused by viruses or bacteria, prion diseases are caused by infectious protein molecules that pass from animals to humans. Although differences between species makes it difficult for prion diseases to spread from one species to another, transmission does occur.Bovine spongiform encephalopathy, as mad cow disease is properly called, can be transmitted to humans by eating meat infected with the disease.

This study might help researchers better determine the risk of exposure to animal prions and silent carriers, said study co-author Vincent Beringue, a scientist at the French National Institute for Agricultural Research.

The findings were published today (Jan. 26) in the journal Science.

Prion diseases are rare

The cause of prion diseases is unknown, but experts believe that somehow, normal proteins may transform into abnormal, harmful prions.

The most common human prion disease, Creutzfeldt-Jakob disease, occurs worldwide. The disease is rare, striking about one out of 1 million people per year, according to the Centers for Disease Control and Prevention (CDC).

It leads to a rapid decrease of mental functioning and movement and ultimately, death, about a year after diagnosis.

Is the species barrier as strong we think?

In the new study, researchers studied transgenic mice that were infected with prions from either sheep or humans, and found that their lymphoid tissues, including the spleen, tonsils, appendix and lymph nodes, had more prions than their brain tissue.

Researchers found, on average, 7 percent of mice's prions in their brains, whereas 65 percent were in their spleens.

"Prion proteins can multiply quite efficiently in the lymphoid tissue," Beringue said. "This was totally overlooked until now, most likely because studies were focused on brain tissue," he said.

The study has significant implications for public and animal health, according to ChristinaSigurdson, who researches prion diseases at the University of California at San Diego, and was not involved with the study.

For example, Sigurdsonsaid, chronic wasting disease is a prion disease found in deer and elk, and is currently spreading in these animals throughout the United States, according to the CDC.

"Although there is evidence of a species barrier for human infection with this disease, we don't know if there is a population of people that may be currently infected with deer or elk prions," she said.

"This is a major concern, because the infection could remain undetected for long periods of time," she added.

Pass it on: Brain diseases may pass from one species to another a lot easier than experts thought.

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Hockey player Derek Boogaard, who died in May, was in the early stages of a degenerative brain disease, researchers said today.

Boogaard's brain showed signs of chronic traumatic encephalopathy (CTE), a condition seen in football players, boxers and other athletes, in which the brain slowly degenerates over time because of repeated blows to the head.

Boogaard died May 13 at the age of 28 of an accidental overdose of alcohol and the painkiller oxycodone, according to ESPN. His brain showed evidence of early CTE in his cerebral cortex, according to the findings of Dr. Ann McKee, co-director of the Boston University Center for the Study of Traumatic Encephalopathy.

The severity of Boogaard's brain changes were more advanced than most other athletes of similar age with CTE, McKee's findings showed. CTE can only be diagnosed by examining brain tissue postmortem.

Boogaard dealt with drug addiction and exhibited abnormal behaviors, including emotional instability and problems with impulse control, along with short-term-memory problems and disorientation, for two years prior to his death, according to a statement from the center.

He had not played professional hockey since Dec. 9, 2010, because of injuries he sustained in a fight, including a reported concussion. Boogaard had been diagnosed with post-concussion syndrome twice, and his family said he spoke of having at least 20 mild concussions, although he reported few of them to his team or medical staff.

Boogaard reportedly participated in 174 career fights in professional hockey, according to the center.

"Very few hockey players engage in as many fights as Boogaard," said Chris Nowinski, co-director of the center, so the finding does not contribute to researchers' knowledge of the risks of normal hockey playing. "Athletes and parents should know that anyone who experiences repetitive brain trauma may be at risk to develop CTE, but we are hopeful that risk is small in hockey."

Nowinski added that two other young non-NHL professional hockey players studied did not show signs of CTE at postmortem examination.

"It is important not to over-interpret the finding of early CTE in Derek Boogaard," said researcher Dr. Robert Cantu. "However, based on the small sample of enforcers we have studied, it is possible that frequently engaging in fistfights as a hockey player may put one at increased risk for this degenerative brain disease."

Still, the link between the structural changes seen in Boogaard’s brain and the behavioral changes and memory problems  he experienced is unclear, the researchers said. His behavioral changes occurred during the same time period he was exhibiting narcotic abuse. 

Just days before Boogaard died, the same researchers had announced that football player Dave Duerson suffered from CTE, according to their examination of his brain. Duerson committed suicide in February, and had sustained at least 10 concussions during his 11-year NFL career. 

McKee also found mild stages of CTE in former NHL players Rick Martin and Bob Probert, and advanced CTE in Reggie Fleming. For 30 years, Fleming showed worsening behavioral and cognitive difficulties, and died in 2009 at the age of 73 with dementia.

McKee has analyzed the brains of over 70 former athletes and more than 50 have shown evidence of CTE, according to the center.

Boogaard played left wing for the Minnesota Wild from 2005-2010 before playing for the New York Rangers during the 2010-2011 season.

Pass it on: Fights In professional hockey games might have contributed to hockey player Derek Boogaard's development of a degenerative brain disease.

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News reports rarely get more revolting: In the last month, two assistant coaches of big-time college sports teams have been publicly accused of sexually abusing children. But for parents — whose top job is to keep their kids safe — that revulsion may be layered with astonishment, because victims often didn't tell others of the alleged abuse until years later.

Add that to several recent cases of school bullying gone too far – some with deadly consequences – and parents have to wonder why they may be the last to learn that their children are living their worst nightmares.

"Fear of disclosure outweighs desire to share, and that's a big problem," said Dr. Victor Fornari, director of child and adolescent psychiatry at North Shore-LIJ Health System in New Hyde Park, N.Y. "Kids are not likely to just initiate a conversation unless their environment is conducive to that. Kids know what parents want to hear and don't want to hear."

But what parent wouldn't want to hear their child is being molested or bullied? And how can the atrocities at Penn State and Syracuse University — where football's Jerry Sandusky and basketball's Bernie Fine, respectively, allegedly victimized young boys — sway parents to keep their radar up?

The first priority is to encourage open, no-holds-barred communication with kids about myriad subjects, including sex abuse and bullying, from very young ages, Fornari said. They're more likely to trust parents enough to divulge scary experiences if they feel safe doing so.

"There isn't one specific way for parents to initiate conversations helping kids disclose potentially sensitive issues," he said. "Parents should have ongoing conversations where kids feel comfortable — not feeling criticized, not feeling judged — and parents can listen."

What signs can parents look for?

There's more than one way to handle speaking with a child or teen if you suspect they're being victimized, said Michele Borba, an educational psychologist in Palm Springs, Calif., and author of "The Big Book of Parenting Solutions: 101 Answers to Your Everyday Challenges and Wildest Worries" (Jossey-Bass, 2009).

"There's no cookie-cutter approach, but you have to follow your suspicion if you feel this is a possibility," Borba said, "especially if you have evidence or a strong suspicion — someone told you, or you're seeing marked changes that are not normal for your child."

What are those changes? According to Fornari and Borba, they include:

• Sleeping poorly
• Clinginess
• Pulling away from certain peers
• Worsening grades
• Loss of interest in usual activities
• Nervousness about phone calls or emails

Of course, some these changes might only signal a minor, temporary setback for a child — such as not making a sports team or getting a part in the school play — and all kids are unhappy sometimes, the experts said. But in the case of abuse or bullying, these changes will typically continue for at least two weeks, Borba said.

What if they don't want to talk?

"Parents can say, 'I'm really concerned, and here's what I'm noticing. I want to make sure you feel safe,'" Borba said. "Often, their body language can tell you even more than words."

"Are they looking uncomfortable, shutting down or pulling back?" she added. "You may see a moment of shame or guilt on their face. Watch to see how your child responds to your questions."

If a child just won't answer any questions or shrugs them off, Fornari recommended taking a lighter approach.

"You don't want to come across like a sledgehammer, because you don't want them to stop the conversation," he said. "Say to them, 'I hope if there is something going on, you feel comfortable coming to me when you're ready.'" And be prepared to consult with a pediatrician or school psychologist for backup.

Above all, parents should trust their gut instincts, Borba said.

"Probably the most telltale sign is a parent who said, 'I just knew,'" she said. "No one knows your child better than you."

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The phenomenon of teenagers using phones or computers to send each other sexual photographs, known as "sexting," is not as widespread as once thought, a new study suggests.

University of New Hampshire researchers conducted a telephone survey to ask 1,560 Internet users between the ages of 10 and 17 whether they'd made, sent or received sexual photographs in the past year.

Only about 1 percent of children were sexting sexually explicit photographs.

"It's somewhat reassuring," said study author Kimberly Mitchell, an associate professor of psychology at the University of New Hampshire. "The media … has portrayed it as a big problem."

But chances are, your children are not sexting, Mitchell said.

Researchers asked questions such as "Have you ever taken nude or nearly nude pictures or videos of yourself?" and "Has anyone ever sent you nude or nearly nude pictures or videos of kids who were under the age of 18 that someone else took?"

A related study showed that law-enforcement agencies respond to about 1,750 cases of sexting each year in the United States.

Both studies were published today (Dec. 5) in the journal Pediatrics.

Defining sexting

Kids' answers during the interviews depended upon how the researchers defined sexting. When researchers asked if children had created or appeared in nude pictures or videos, 2.5 percent said yes. However, only 1 percent of children said the photos were sexually explicit, showing bare breasts, genitals or bottoms.

More than 7 percent of children said they had received nude or nearly nude photographs of others, while nearly 6 percent said they'd received sexually explicit photographs.

Children's answers included: "This boy had four pictures of a naked girl — he was showing everyone in the classroom," and "I was just dating a boy and he wanted a picture and I just sent him my picture."

Other studies debunked

The findings debunk other, less rigorous studies of teens and sexting, the researchers said. For instance, one study used an Internet panel and included 18-and-19-year-olds. Some studies also didn't distinguish between nearly nude photographs and sexually explicit photographs.

"Often times, [the photographs] weren't sexually explicit," Mitchell said. "We find, across the board, that kids are pretty smart about using technology."

When sexting was considered serious enough for legal action, two-thirds of the cases involved an aggravating circumstance such as an adult being involved, or nonconsensual or malicious behavior, according to the study of law-enforcement agencies. 

Researchers mailed surveys to a sample of 2,712 law-enforcement agencies and found 3,477 cases involving sexting during 2007 and 2008.

About 36 percent of cases involved adults, and 19 percent involved criminal behavior beyond creation of the sexual image.

About a third of the cases were considered "experimental," meaning that the children involved were in a romantic relationship or were engaged in attention-seeking behavior.

Police made arrests in 62 percent of cases involving an adult, 36 percent of cases where a youth was engaged in aggravated behavior and 18 percent of experimental cases.

The study advances the current understanding of sexting by delving further into the details than any other research to date, said Amanda Lenhart, a senior research specialist with the Pew Research Center, in Washington, D.C.

"The researchers have been able to ask very specific questions to target a narrow definition of sexting …  as well as a more-detailed understanding of how the images were created, shared and received," Lenhart said. "Their research findings also closely match my most recent work on this topic, where we found 2 percent of teens 12 to 17 say they have sent a sexually suggestive nude or nearly nude image of themselves to someone else, and 16 percent of all teens say they have received them."

Mitchell acknowledged that her study involved only children who use the Internet, while saying nothing about the small percentage (about 5 percent) of kids who don't. "To be involved with sexting you don't have to be an Internet user," she said. "I don't think we're missing many kids, but we could be missing some."

Pass it on: Despite widespread concern about sexting, few children actually engage in sending or receiving sexually explicit photographs.

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The gap between the healthiest people and the least healthy in the United States has grown among those born in recent decades, and will likely continue to grow in the coming generations, a new study suggests.

The researchers found the disparity in healthiness generally declined for each generation from the start of the 20th Century through the baby boomers, who were born between the mid-1940s and mid-1960s, but the gap subsequently has grown again in later generations and is now approaching what it was in the early 1900s.

"The dramatic rising health disparities for cohorts born after 1980," said Hui Zheng, lead author of the study and assistant professor of sociology at Ohio State University, surprised the researchers.

Moreover, the gap is expected to continue growing.

"We will expect health disparities in the whole population will increase as the current young cohorts grow older and replace the current older cohorts," Zheng said.

The study did not directly examine the reasons for the widening gap, Zheng said. But other research has shown it may be driven by income inequality, which has increased over the past three decades, along with increased immigration and the growing 'digital divide' between people who readily and easily access health information on the Internet and those with less access.

The study is published in the December issue of the journal American Sociological Review.

Decades of data

The researchers analyzed data gathered from 702,000 participants in the National Health Interview Survey, a large government health study conducted between 1984 and 2007, which included interviews with older adults, enabling the researchers to analyze the health disparity among people born as long ago as 1899.

People were asked to rate their own health on a five-point scale; though there are drawbacks to relying on self-reported measures of health, overall, studies have shown that self-reports generally produce reliable results, the researchers said.  

When the researchers compared the gap between the healthiest and least-healthy people born in the early 1960s with the gap between those born in the 1980s, they found it had widened by 26 percent, Zheng said.

Overall, health increased from 1984 until 1990. It then decreased until the mid-1990s. It rose again until the late 1990s, but has been decreasing since then, according to the study.

In general, those who were white, married, more educated, had a job and had more income rated themselves as being in better health.

But of those factors, the one with the largest impact on health was employment. Those who were employed rated themselves 0.39 points healthier, on average, than those who weren't, whereas being married brought a 0.02-point increase, on average, and each additional year of education brought a 0.06-point increase.

Our health, as we age

The researchers also quantified the disparity within any cohort, or group of people of the same age, over time. They found that during young adulthood, there is relatively little disparity — most are generally healthy.

The disparity within any group increases and peaks when people are around age 55, after which it declines again. The lower disparity seen in older adults could be because sicker people die, leaving only healthier people, or because there is a prevalence of medical conditions among older people, according to the study.

In every generation, women in the study rated themselves as less healthy than men.

There is a relatively large gap between the sexes in early adulthood, with men rating themselves as healthier than women, according to the study. It narrows until about age 61, because men are more likely to experience more-severe forms of chronic conditions such as heart disease, but then widens again, as only the healthier men survive and there is a relatively larger share of women with poorer health at older ages.

Pass it on: The difference between the healthiest and the least-healthy adults in the United States is growing.

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Generosity between spouses is a key element to a happy marriage, a new study says.

In essence, generosity is the amount of giving that goes on within a relationship, which can mean anything from making your spouse a cup of coffee, to ordering flowers or providing a backrub.

In the study, couples who reported a high amount of generosity in their relationship were five times more likely to say their marriage was "very happy," compared with those who reported a low amount of generosity. All couples in the report had children.

When a person is generous to his or her spouse, "The underlying message is, you're valuable, you're important," said Dr. Anthony Castro, an assistant professor of psychiatry at the University of Miami Miller School of Medicine, who was not involved in the study.

However, generosity was not as important as sex, researchers found. In the study, married men and women who reported above-average sexual satisfaction in their relationship were 10 to 13 times more likely to describe their marriage as "very happy," compared with those who reported below average sexual satisfaction.

But factors such as generosity may make sex better, according to the study. Couples who reported high levels of generosity, commitment and quality time together also reported high levels of sexual satisfaction. And wives were more likely to be sexually satisfied if they shared household chores with their husbands.

"What happens outside of the bedroom seems to matter a great deal in predicting how happy husbands and wives are with what happens in the bedroom," said study researcher W. Bradford Wilcox, an associate professor of sociology at the University of Virginia.

Predictors of a happy marriage

The study, part of the National Marriage Project,surveyed more than 1,400 heterosexual couples between the ages of 18 and 46.

Fifty percent of women and 46 percent of men who reported above-average generosity in their relationships described their marriages as "very happy." On the other hand, just 14 percent of each sex with below-average generosity in their relationship described their marriage as "very happy."

Generosity works best if you give your spouse something he or she likes, Wilcox said. "[It's] signaling to your spouse that you know them, and are trying to do things for them that are consistent with your understanding of them," Wilcox said. But if, for example, your spouse delights in almond mochas, and you get her black coffee instead, it might not be very helpful, Wilcox said.

Based on the responses, the researchers compiled a list of the top five predictors of a very happy marriage. For men and women, sexual satisfaction ranked first, followed by level of commitment (a sense of "we-ness"), generosity and a positive attitude toward raising children. For women, the fifth factor was above-average social support from friends and family, and for men, the fifth factor was spirituality within a marriage.

Each relationship is unique

While the factors identified in this study may be a guide to a good relationship, they are based on responses from a large population and don't necessarily apply to individual couples, Castro said.

"Every individual situation is different," Castro said. For instance, a couple may find themselves falling into the 14 percent of couples who are very happy without a high level of generosity.

"Each specific relationship needs to be thought about individually, depending on both individual and partners' needs," Castro said.

The new study was conducted in partnership with the Center for Marriage and Families at the Institute for American Values, a nonprofit organization whose mission is to increase the proportion of U.S. children growing up with their two married parents.

Pass it on: Generosity is an important factor in a happy marriage.

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