Audiovisual processing differences in autism spectrum disorder revealed by a model-based analysis of simultaneity and temporal order judgments

摘要

The ability to integrate auditory and visual information is crucial to everyday life and there are mixed results regarding how Autism Spectrum Disorder (ASD) influences audiovisual integration. The audiovisual Temporal Integration Window (TIW) indicates how precisely sight and sound need to be temporally aligned to perceive a unitary audiovisual event. We used a model-based approach (Garcia-Perez & Alcala-Quintana, 2012) to compare the TIW of 26 adult males with ASD to age and IQ-matched typically developed (TD) males. The stimuli included the following audiovisual pairings with varying degrees of asynchrony: 1) a beep with a flashing circle (BF), 2) a point-light drummer with a drumbeat (PLD), 3) a face moving to say a single word and the voice saying the word (FV). In separate blocks participants were asked to make either simultaneity judgments (SJ) or temporal order judgments (TOJ) when presented with these stimuli. The model-based approach provides estimates of the TIW width as well as model parameters related to sensory and decisional factors of audiovisual processing. Analysis of the TIW width showed main effects of stimulus and group on SJ (wider TIW in the ASD group), whereas for TOJ no main effects were found. The combined model using both SJ and TOJ reported a main effect of stimulus and a marginal effect of group. Analysis of the model parameters showed group differences in both sensory and decisional factors. A decisional factor difference was found only for SJ, suggesting less temporal resolution in the ASD group. A sensory factor difference was found in the auditory but not the visual domain. This suggests that SJ is more sensitive to reveal TIW differences in ASD and that these differences appear to arise from processing differences in the auditory domain of audiovisual processing.