Scientists might know you better than you know yourself.
Neuroscientists from UCLA used a brain scan to predict whether people would use sunscreen during a one-week period. And their predictions were more accurate than those made by the participants themselves.
"There is a very long history within psychology of people not being very good judges of what they will actually do in a future situation," said the study's senior researcher Matthew Lieberman, a UCLA professor of psychology and of psychiatry and biobehavioral sciences. "Many people 'decide' to do things but then don't do them."
The new results could help tailor commercials and public-health messages for the greatest success.
Lieberman and UCLA colleague Emily Falk, the lead study researcher, scanned the brains (using functional magnetic resonance imaging) of 20 participants as they watched and listened to public service announcements on the importance of using sunscreen. Participants also indicated their attitudes toward using sunscreen and whether they expected to use it over the next week.
The participants were then followed up with to find out the number of days they actually used sunscreen.
In their analysis of the results, the researchers focused on part of the brain's medial prefrontal cortex, which is located in the front of the brain between the eyebrows and is associated with self-reflection.
"It is the one region of the prefrontal cortex that we know is disproportionately larger in humans than in other primates," Lieberman said. "This region is associated with self-awareness and seems to be critical for thinking about yourself and thinking about your preferences and values."
More activity in that brain region reliably predicted a person is more likely to increase sunscreen use the following week.
Neural focus groups
The results could have implications for testing out commercials, movie trailers and public-health campaigns. In so-called neural focus groups, advertisers and public health officials could see which messages are most effective by monitoring brain activity in participants.
For instance, different brain regions might be important for persuading people to spread the word (through e-mail or face-to-face) about a health message, product or service. In fact, Lieberman and Falk are studying this issue of "creating buzz."
The findings could also help, say, teachers communicate in a way so their students won't tune out, and doctors to more successfully convince patients to stick to their instructions, the researchers say.
The study, the first so-called persuasion study in neuroscience to predict behavior change, will be published June 23 in the Journal of Neuroscience.