Background: Studies in our lab indicate that individuals with Autism Spectrum Disorder (ASD) show equivalent visual sensitivity to human and object movement, while typical controls demonstrate heightened visual sensitivity to human movement. These findings suggest that perceptual processes may contribute to social deficits in ASD. Notably, autistic traits are not limited to clinical populations.  The Autism-Spectrum Quotient (AQ) measures autistic traits in adults with normal IQ.
Objectives: Our goal is to understand how individuals with ASD perceive their social worlds.  We begin by identifying the relationship between the magnitude of autistic traits and visual sensitivity to social (i.e., human) and non-social (i.e., object) movement. 
Methods: Participants completed the AQ and a classic psychophysical motion detection task. Point-light displays of a walking person and moving tractor were constructed from motion capture data. In a blocked design, the points depicting the person or tractor were presented coherently or scrambled. Displays were embedded in point-light masks that limited the utility of local motion processes. Participants reported whether or not they detected the presence of the person or tractor.
Results: Observers with low AQ score (i.e., less autistic traits) showed greater visual sensitivity to human movement than object movement. Observers with high AQ scores (i.e., more autistic traits) showed equivalent visual sensitivity to human and object motion. This group had patterns of perceptual performance that resembled that of observers with ASD in our previous studies.
Conclusions: These results indicate that typical individuals with more autistic traits may perceive human and object motion similarly to individuals with a diagnosis of ASD. Assessing neurotypical participants’ AQ scores is a useful way of studying the broader autism phenotype while avoiding the difficulties, such as co-morbid diagnoses, associated with testing clinical populations.