MADISON, Wis., Dec. 5 -- Severe social deficits in males with autism has been traced by investigators here to shrinkage of the amygdala, the component of the limbic system that governs non-verbal responses to threats.
In a small study of eye-tracking and facial recognition in teens and young men with autism, those who were slowest at distinguishing emotional expressions had amygdalae that were smaller than normal in volume, reported Richard J. Davidson. Ph.D., of the University of Wisconsin.
The study participants who did worst at differentiating expressions turned out to have had the greatest degree of social impairment in childhood, the investigators reported in the December issue of the Archives of General Psychiatry.
"These results provide the first evidence for a link between objective measures of social impairment and amygdala structure in autism," the authors wrote.
