ADVERTISEMENT
See Inside June 2005

New View on Autism



“Look me straight in the eye” is not something autistic children find easy to do. Avoiding eye contact is a hallmark of this developmental disorder, and researchers have looked for the cause in the brain's fusiform gyrus region, active in face recognition. But instead of an underactive fusiform, says Kim Dalton, an assistant scientist at the University of Wisconsin–Madison, an overactive amygdala may be at fault.

Autism greatly weakens an individual's capacity to socialize and communicate. Avoiding eye contact is a problem because it is a crucial source of “subtle cues that are critical for normal social and emotional development,” Dalton says. Working with Richard Davidson, a professor of psychiatry and psychology at the university, Dalton compared autistic teenagers with average teens. She observed their brains with magnetic resonance imaging as they looked at pictures of familiar faces and other faces that showed various emotions. The autistic teens took longer to recognize familiar faces and made more mistakes in identifying the emotions of others.

By tracking the subjects’ eye movements and brains, Dalton and Davidson found that the autistic children spent less time fixing their gaze on the eyes in the photographs. Yet the autistic group “showed greater activation of the amygdala and orbitofrontal gyrus”—areas associated with emotional response, Dalton says. These results suggest that in autistics, viewing faces causes overarousal of emotional centers, resulting in avoidance. The quieter fusiform response is a result, not a cause. Understanding this link may help scientists devise ways of training autistic children to look at faces, helping them form stronger social bonds.

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Holiday Sale

Give a Gift &
Get a Gift - Free!

Give a 1 year subscription as low as $9.99

Subscribe Now! >

X

Email this Article

X