Representation of facial identity and expression in Persons with Autism Spectrum Disorder; Identity- and Expression- contingent aftereffect








Persons with Autism Spectrum Disorder(ASD) have impairments in face processing. Recent studies examined an underlying mechanism of the deficit by using an “face adaptation paradigm”, which is an experimental method developed for testing the norm-based coding model. In this paradigm, temporary perceptual change can be observed in response to prolonged exposure to a face (‘adaptation’). The change caused by adaptation is called ‘aftereffect‘, which is considered as evidence of norm-based representation of face. Several studies revealed that persons with ASD showed reduced aftereffects in both facial identity and expression compared to typically developing (TD) people. These results suggested that the representation of face is atypical in ASD group, in an aspect of facial identity and expression in isolation. However, no previous study has examined the integrative representation of these two elements in persons with ASD. The purpose of the study was to test the ‘expression-contingent identity aftereffect’ (exp.1) and ‘identity-contingent expression aftereffects’ (exp.2). By measuring effect of identity change on expression aftereffect or vice versa, integrative representation patterns of identity and expression in two groups were compared.