Speech-and-gesture integration in high functioning autism

摘要

This study examined iconic gesture comprehension in autism, with the goal of assessingwhether cross-modal processing difficulties impede speech-and-gesture integration. Par-ticipants were 19 adolescents with high functioning autism (HFA) and 20 typical controlsmatched on age, gender, verbal IQ, and socio-economic status (SES). Gesture comprehen-sion was assessed via quantitative analyses of visual fixations during a video-based task,using the visual world paradigm. Participants' eye movements were recorded while theywatched videos of a person describing one of four shapes shown on a computer screen,using speech-and-gesture or speech-only descriptions. Participants clicked on the shapethat the speaker described. Since gesture naturally precedes speech, earlier visual fixationsto the target shape during speech-and-gesture compared to speech-only trials, would sug-gest immediate integration of auditory and visual information. Analyses of eye movementssupported this pattern in control participants but not in individuals with autism: iconicgestures facilitated comprehension in typical individuals, while it hindered comprehensionin those with autism. Cross-modal processing difficulties in autism were not accounted forby impaired unimodal speech or gesture processing. The results have important implica-tions for the treatment of children and adults with this disorder.