Colloquium: Heterogeneity in autism: Insights from studies of face processing

Autism is a heterogeneous disorder defined purely in terms of observable behaviour. Yet the overwhelming majority of studies of cognition in autism are concerned only with group averages, determining whether or not there is a statistically significant difference between autistic and non-autistic participants on a given measure. An alternative approach is to focus more on individual differences within autism. The advantages of this approach are illustrated by our own research on face processing in autism. Previous autism group studies are equally divided among those finding evidence for impaired or unimpaired facial identity recognition. Our data demonstrate similarly wide variation in face recognition skills at the individual level, perhaps explaining the inconsistency of earlier findings. Further studies have shown that, within our autism group, face recognition difficulties are associated with differences in social attention and specific aspects of face scanning patterns. Moreover, autistic children's face recognition skills are associated with their parents' performance on a similar task. These findings point towards possible mechanisms of face recognition impairment and, ultimately, may lead to the identification of meaningful cognitive subgroups within autism. In ongoing work, we are extending this approach to other aspects of autism, including language impairment and motor coordination.