Shedding light on shyness
A small part of the brain is providing new clues to social anxiety disorders. Researchers at the Harvard Medical School studying images of brain activity found that adults who were timid as children display very different brain signal patterns from those who were bold and outgoing when younger.
The findings come from a 2-decade-old research project that has followed a group of more than 100 people from age 2 to adulthood, monitoring their behavior and psychiatric changes over time.
Most of the participants are now age 21 or 22. At age 2, they were classified as either inhibited (extremely shy) or uninhibited (bold and outgoing). Researchers found that being inhibited at age 2 was a powerful risk factor for developing social anxiety disorders, such as panic disorder and social phobia, in late childhood and early adolescence.
Most recently, researchers used a new technology called functional magnetic resonance imaging to monitor brain activity in the two groups while they looked at pictures of familiar and unfamiliar faces. Brain signals in the amygdala, an almond-shaped part of the brain involved in processing emotional stimuli, intensified when people in the inhibited group came across faces they didn’t recognize.
Study author Dr. Carl E. Schwartz, of Massachusetts General Hospital and Harvard Medical School, said the findings suggest the amygdala may play a second, subtler role in helping people detect novelty and change in their surroundings.
More important, the research reveals something that Schwartz calls “a footprint of early differences in temperament.” That is, people who were bashful infants continue to show physiological evidence of timidity later in life, even if they’ve outgrown their shyness.
If the same signal patterns could be detected in young children, brain imaging may come to play a role in the early identification of those at risk of developing anxiety disorders. Such disorders affect some 19 million U.S. adults, according to the National Institutes of Health.
A more immediate use of neural imaging may be to help doctors better diagnose psychiatric illness, said Schwartz. “Currently, we depend too much on verbal reports because we’re still struggling to find other tools to look at the brain.”
The study, published in the June 20 issue of the journal Science, examined 22 adults who were participants in the original study.
Schwartz says he and his colleagues hope to perform a larger study in the future. They also plan additional brain-imaging studies of infants if they can overcome some of the obvious challenges. “There are practical difficulties,” said Schwartz. “Kids like to wiggle and move.”
