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NEW YORK (Reuters Health) - It's no secret that teens care a lot about what other people think of them. And new research using brain scans suggests that girls' response to the prospect of being sized up by a peer gets stronger as they progress through adolescence.
The current findings offer a hint about why girls' risk of depression and anxiety rises as they enter adolescence-and why these mental health issues are often centered on how others perceive them, according to Dr. Amanda E. Guyer, who led the study, and her colleagues.
In her research at the National Institute of Mental Health in Bethesda, Maryland, Guyer used a technique called functional magnetic resonance imaging (fMRI) to look at oxygen consumption within specific regions of the brain, with the goal of finding out how teens' brain activity corresponds to the dramatic changes that are happening in their social behavior.
In this study, she and her colleagues were looking at a group of structures deep within the brain -- including the nucleus accumbens, insula, hypothalamus, hippocampus, and amygdala -- that are involved in emotion and social interactions.
She and her colleagues hypothesized that these brain regions would be activated more strongly in response to being evaluated by one's peers as teens got older, and that this activation would be stronger in girls than in boys.
To investigate, she and her colleagues had 34 boys and girls ranging in age from 9 to 17 participate in a two-part "Chatroom Task." In the first phase, study participants, all of whom were in good mental health, were told they'd be participating in an investigation of how teens communicate in online chatrooms.
While in the fMRI scanner, they looked at 40 different photographs of teens and rated each from 0 to 100 based on how interested they were in interacting with that person.
Researchers told them that their pictures would also be evaluated by other teens as part of the study, and that they would be matched up with a "mutually high-interest 'participant'" later on. Two weeks later, the study participants looked at the photos again, but this time researchers asked them how interested they thought that the person in the photo would be in interacting with them.
Among the girls, the researchers found, the difference in activation of emotion-related brain areas between when they thought about a "high-interest" peer evaluating them and when they thought about a "low-interest" peer doing so increased as a girl got older.
While a younger girl's "socioeconomic calculus" might be directed toward avoiding low-interest peers, the researchers suggest, older girls may focus more on approaching high-interest peers.
While the findings suggest a maturation in social relationships that happens in the female brain in adolescence, the fact that these changes didn't happen in boys shouldn't be seen as meaning that males are socially immature, Guyer told Reuters Health.
An individual peer's perception "just might not hit home in the same way as it does for girls," added Guyer, who is now at the University of California at Davis. Boys "might just be focused on other aspects of social relationships."
SOURCE: Child Development, July/August 2009.