You may have heard people describe themselves as strictly "right-brained" or "left-brained," with the left-brainers bragging about their math skills and the right-brainers touting their creativity. That's because the brain is divided down the middle into two hemispheres, with each half performing a fairly distinct set of operations.
Much of what is known about brain function is owed to Roger Sperry, whose experiments examined the way the human brain's hemispheres operate both independently and in concert with each other. The two hemispheres communicate information, such as sensory observations, to each other through the thick corpus callosum that connects them.
The brain's right hemisphere controls the muscles on the left side of the body, while the left hemisphere controls the muscles on the right side of the human body. When you wink your right eye, that's the left side of your brain at work. Because of this criss-cross wiring, damage to one side of the brain affects the opposite side of the body.
In general, the left hemisphere is dominant in language: processing what you hear and handling most of the duties of speaking. It's also in charge of carrying out logic and exact mathematical computations. When you need to retrieve a fact, your left brain pulls it from your memory.
The right hemisphere is mainly in charge of spatial abilities, face recognition and processing music. It performs some math, but only rough estimations and comparisons. The brain's right side also helps us to comprehend visual imagery and make sense of what we see. It plays a role in language, particularly in interpreting context and a person's tone.
As for whether a person is right-brained or left-brained or even right-handed or left-handed the uses and preferences of the brain's two sections are far more complex than just a simple left vs. right equation. For example, some people throw a ball with their right hand but write with their left. [Southpaw Stats: 11 Fun Facts About Lefties]
The brain carefully balances and assigns control of certain functions to each side it's all nature's way of ensuring that the brain ultimately splits up tasks to maximize efficiency. Most people are right-hand dominant which is actually controlled by the left side of the brain.
"Brain asymmetry is essential for proper brain function," professor Stephen Wilson of University College London told Live Science, a sister site of Life's Little Mysteries. "It allows the two sides of the brain to become specialized, increasing its processing capacity and avoiding situations of conflict where both sides of the brain try to take charge."
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