An event related potentials method for assessing audiovisual speech integration: Implications for children with autism spectrum disorders

Abstract

Perceptual studies of children with autism spectrum disorders (ASD) strongly implicate deficits in processing of audiovisual (AV) speech. Previous research with AV stimuli has typically been conducted in the context of auditory noise or with mismatched auditory and visual (“McGurk”) stimuli. Although both types of stimuli are well-established methods for testing typically developing (TD) participants, they may create additional processing problems for children with ASD. To more precisely examine audiovisual (AV) speech perception in children with ASD, we developed a novel measure of AV processing that involves neither noise nor AV cross-category conflict. The speech stimuli include clear exemplars of the syllable /ba/ and a modified version of /ba/ in which the consonant is substantially weakened so that the syllable is heard as “/a/ ”. These are dubbed with a video of the speaker saying /ba/. Audiovisual integration should result in the visual information effectively “restoring” the weakened auditory “/a/ ” cues so that the stimulus is perceived as /ba/. Using event related potentials (ERP), we will present evidence from typically developing adults and preliminary results from children with ASD and TD to examine whether children with ASD are weaker in AV speech integration.