An emotion circuit is activated more in girls as they grow older, but not in boys as they size up their peers according to their own standards, a new study has revealed.
The study by Daniel Pine, M.D., of the National Institute of Mental Health (NIMH), part of National Institutes of Health, and colleagues, shows how emotion circuitry diverges in the male and female brain during a developmental stage in which girls are at increased risk for developing mood and anxiety disorders.
"During this time of heightened sensitivity to interpersonal stress and peers' perceptions, girls are becoming increasingly preoccupied with how individual peers view them, while boys tend to become more focused on their status within group pecking orders," explained Pine. "However, in the study, the prospect of interacting with peers activated brain circuitry involved in approaching others, rather than circuitry responsible for withdrawal and fear, which is associated with anxiety and depression."
Thirty-four psychiatrically healthy males and females, aged 9 to 17, were ostensibly participating in a study of teenagers' communications via Internet chat rooms. They were told that after an fMRI (functional magnetic resonance imaging) scan, which visualizes brain activity, they would chat online with another teen from a collaborating study site. Each participant was asked to rate his or her interest in communicating with each of 40 teens presented on a computer screen, so they could be matched with a high interest participant (see picture below).
Two weeks later, the teens viewed the same faces while in an fMRI scanner. But this time they were asked to instead rate how interested they surmised each of the other prospective chatters would be in interacting with them.