| The amygdala theory of autism proposes that the hallmark symptoms of social impairment arise because of an inability to process the emotional relevance of social information, especially from faces. This hypothesis has garnered substantial support, but studies in humans have focused almost exclusively on measures of face processing. We investigated emotion processing abilities for nonface stimuli with lower social relevance, in a sample of 37 adolescents and adults with high-functioning Autistic Disorder (the AD group) and a control group of 38 age- and IQ-matched 38 Typically Developing individuals (the TD group). Group differences in patterns of response to emotionally relevant versus emotionally neutral stimuli were examined. The AD group demonstrated the same facilitation of response (greater accuracy and faster reaction time) when processing emotion stimuli as the controls. The AD group also showed no difference from controls in performance on emotional decision-making tasks. In contrast, the AD group was impaired on a socially relevant task of assigning emotion descriptors to photographs of eyes. The AD group also demonstrated significantly more anxiety, particularly social anxiety, on a self-report measure. Implications of these results for the amygdala theory of autism are discussed. |
