P2-27: Electrophysiological Correlates of Conscious and Unconscious Processing of Emotional Faces in Individuals with High and Low Autistic Traits

Abstract

LeDoux (1996 The Emotional Brain) has suggested that subconsciouss presentation of fearful emotional information is relayed to the amygdala along a rapid subcortical route. Rapid emotion processing is important because it alerts other parts of brain to emotionally salient information. It also produces immediate reflexive responses to threating stimuli in comparison to slower conscious appraisal, which is of important adaptive survival value. Current theoretical models of autism spectrum disorders (ASD) have linked impairments in the processing of emotional information to amygdala dysfunction. It can be suggested that impairment in face processing found in autism may be the result of impaired rapid subconscious processing of emotional information which does not make faces socially salient. Previous studies examined subconscious processing of emotional stimuli with backward masking paradigms by using very brief presentation of emotional face stimuli proceeded by a mask. We used an event-related potential (ERP) study within a backward masking paradigm with subjects with low and high autistic tendencies as measured by the Autism Spectrum Quotient (AQ) questionnaire. The time course of processing of fearful and happy facial expressions and an emotionally neutral face was investigated during subliminal (16 ms) and supraliminal (166 ms) stimuli presentation. The task consisted of an explicit categorization of emotional and neutral faces. We looked at ERP components N2, P3a, and also N170 for differences between subjects with low (< 12) and high (> 19) AQ.