It is known that the adult visual memory system is fractionable into functionally independent cognitive subsystems, selectively susceptible to brain damage. In addition, there have been hints from studies with individuals with autism that these cognitive subsystems can fractionate developmentally. However, there has been a paucity of systematic investigations. The present study involves the analysis of visual memory of a population of individuals with autism and age- and VIQ-matched comparison individuals. The individuals with autism presented selective impairments in face recognition in comparison to both the age- and VIQ-matched comparison populations. In addition, they were impaired relative to the age-matched comparison group on recognition memory for potential agents (i.e. objects capable of self-propelled motion) whether they were living (cats and horses) or non-living (motorbikes). In contrast, they were selectively superior relative to the VIQ-matched comparison group on recognition memory for such objects as topographical stimuli (buildings) and leaves that clearly do not have agency. The data is interpreted in terms of reduced sensitivity to agency cues in individuals with autism and general information processing capacity.

Computer-presented animations were used to elicit attributions of actions, interactions and mental states. Two triangles moved around the screen according to one of three conditions. Descriptions of the animations were rated according to accuracy and type of description. Adults predominantly used action descriptions for Random animations (e.g. bouncing), interaction descriptions for Goal-directed (G-D) sequences (fighting), and mentalising descriptions for Theory of Mind (ToM) sequences (tricking). High-functioning children with autism used mentalising descriptions less often than normally developing 8-year-olds, but as often as did children with general intellectual impairment. However, the autism group frequently referred to mental states that were inappropriate to the animation. Even those children with autism who passed standard false belief tasks showed inappropriate descriptions of ToM animations, revealing continuing impairments in mentalising on-line.

Autism is a biological disorder which affects social cognition, and understanding brain abnormalities of the former will elucidate the brain basis of the latter. We report structural MRI data on 15 high-functioning individuals with autistic disorder. A voxel-based whole brain analysis identified grey matter differences in an amygdala centered system relative to 15 age- and IQ-matched controls. Decreases of grey matter were found in anterior parts of this system (right paracingulate sulcus, left inferior frontal gyrus). Increases were found in posterior parts (amygdala/peri-amygdaloid cortex, middle temporal gyrus, inferior temporal gyrus), and in regions of the cerebellum. These structures are implicated in social cognition by animal, imaging and histopathological studies. This study therefore provides converging evidence of the physiological basis of social cognition.