Looking you in the mouth: abnormal gaze in autism resulting from impaired top-down modulation of visual attention

People with autism are impaired in their social behavior, includingtheir eye contact with others, but the processes that underliethis impairment remain elusive. We combined high-resolutioneye tracking with computational modeling in a group of 10 high-functioningindividuals with autism to address this issue. The group fixatedthe location of the mouth in facial expressions more than didmatched controls, even when the mouth was not shown, even infaces that were inverted and most noticeably at latencies of200–400 ms. Comparisons with a computational model ofvisual saliency argue that the abnormal bias for fixating themouth in autism is not driven by an exaggerated sensitivityto the bottom-up saliency of the features, but rather by anabnormal top-down strategy for allocating visual attention.