Immediate Social Context in Face Processing: An ERP Study of Autism

Background: Previous research has shown that individuals with autism fail to attribute social meaning to ambiguous visual stimuli, resulting in maladaptive mental representations of the social environment. In contrast, typical individuals, but not individuals with autism, show enhanced face-related electrophysiological brain activity (N170) when viewing ambiguous stimuli subsequent to viewing face-relevant contextual cues. In typical viewers, face-sensitive areas of the fusiform gyrus also activate in the absence of intrinsic facial features when a face is implied by the context of a human form. Previous research has not yet addressed whether individuals with autism imbue ambiguous stimuli with social meaning in this type of immediate social context.

Objectives: To investigate the N170 as an electrophysiological index of imputation of social meaning in autism.

Methods: Continuous ERP data were recorded while adolescents with autism (n=15) and typical controls (n=15) viewed images of degraded faces with a human body, degraded faces alone, bodies alone, clear faces alone, and clear faces on bodies.

Results: Analyses replicated findings of increased N170 amplitude to ambiguous stimuli subsequent to viewing face-related contextual cues in typical individuals but not in individuals with autism. Analyses in progress will examine between-group differences in enhanced N170 to ambiguous stimuli presented within an immediate social context.

Conclusions: Determining whether face-specific N170 responses can be elicited by immediate contextual cues will provide insight into the clinical problem in autism of failing to interpret ambiguous stimuli in socially meaningful ways, a critical ability for optimizing adaptive responses to the surrounding social environment. Investigating this failure will offer insight into the mechanisms of social brain dysfunction in autism, an objective critical for effective intervention and early detection.