Abstract
It is known that Autistic Spectrum Conditions (ASCs) are associated with perceptual difficulties, and it has been suggested that the perception of motion may be affected. Since human bodies in motion provide a source of information about instrumental and social aspects of behaviour, we examined the perception of human activity from minimal displays of recorded actions with ASC and neuro-typical adults. We developed several tests to compare the perceptual performance of both groups using displays that spanned a range of visual information processing requirements. Task 1 (detection) compared low level processing of visual motion information, and measured participants thresholds for the detection of point light displays (PLDs) of human movement in noise. Task 2 (action recognition) tested differences in the ability to discriminate between PLDs of action blends constructed from knocking and lifting movements, and tapped the ability of both groups to process instrumental human actions. Task 3 (emotional style recognition) tested differences in the ability to recognise the affect of actors performing throwing actions in an angry, happy, neutral and sad manner, from PLDs of human arm movements. Preliminary results suggest atypical processing on all tasks for the ASC group. Motion-processing deficits were apparent in that participants in the ASC group required more signal information than the neuro-typical group to accurately detect human movement. Differences between the groups were clearer on the emotion task than on the action task, consistent with the findings of dissociable neural pathways for perception of expressive and instrumental gestures.