Face composite effects reveal abnormal face processing in Autism spectrum disorders

Although it has been suggested that individuals with an Autism spectrum disorder (ASD) process faces less holistically than typically developing controls, there are few direct investigations of this hypothesis. This question was addressed before using the composite paradigm (Teunisse, J. P., & de Gelder, B. (2003). Face processing in adolescents with autistic disorder: The inversion and composite effects. Brain Cognition, 52(3), 285-294.). The results had revealed that adolescents with ASDs were less sensitive than controls to the misalignment of face parts and it was concluded their face processing was less holistic. However, because of shortcomings of the design, it was not possible to distinguish whether individuals with Autism processed both aligned and misaligned composites in a part-based fashion, or both in a holistic fashion. We compared adolescents with ASDs to controls matched on sex, age and IQ on a more complete version of the composite paradigm. The results indicate that individuals with ASDs, like controls, experience interference from facial features that they are told to ignore. However, while such interference is released for controls if parts of face composites are misaligned, individuals with ASDs show comparable interference from irrelevant parts regardless of alignment. Two different interpretations are discussed, both compatible with the idea that perceptual and or attentional abnormalities in ASDs result in a diminished level of expertise for faces.