Individuals with Autism can Categorize Facial Expressions

The ability of high-functioning individuals with autism to perceive facial expressions categorically was studied using eight facial expression continua created via morphing software. Participants completed a delayed matching task and an identification task. Like undergraduate male participants (N = 12), performance on the identification task for participants with autism (N = 15) was predicted by performance on the delayed matching task for the angry-afraid, happy-sad, and happy-surprised continua. This result indicates a clear category boundary and suggests that individuals with autism do perceive at least some facial expressions categorically. As this result is inconsistent with findings from other studies of categorical perception in individuals with autism, possible explanations for these findings are discussed.