Abstract
Research suggests that deficient multisensory integration (MSI) may partially underlie sensory-seeking or sensory-aversion behaviors in Autism Spectrum Disorders (ASD) (Iarocci & McDonald, 2006). Most of the evidence supporting this hypothesis comes from studies that use socio-communicative stimuli (i.e., speech, faces) or complex cognitive tasks. This study’s goal was to investigate MSI abilities in ASD using low-level stimuli that are void of social content to disentangle multisensory integration from the confounding role of a possible social deficit. To do so, 20 adolescents / adults with and without ASD completed 2 low-level MSI tasks. For the flash-beep illusion task (Shams et al. 2000), participants responded whether they saw 1 or 2 flashes (F) while simultaneously hearing 0, 1, or 2 beeps (B). They were exposed to four non-illusion trials (i.e., 2F2B, 2F0B, 1F1B, 1F0B) and two illusion trials (i.e., fission/fusion illusions), whereby a discordant number of flashes and beeps were presented. Illusion susceptibility (i.e., accuracy) was measured. For the target detection task, participants were asked to respond as quickly and accurately as possible (using a button press) to either visual (flash), auditory (beep) or audiovisual stimuli (flash and beep presented together) (Williams et al., 2010). RTs were measured for all conditions. For the flash-beep illusion task, the ASD group was equally susceptible to the fission illusion, and significantly more susceptible to the fusion illusion. This indicates no evidence of impaired MSI in ASD, and may even speak to a more automatic and less selective MSI process. For the target detection task, no between-group differences in RT were found across conditions; both groups demonstrated multisensory facilitation on audiovisual trials. Results suggest that MSI for simple, non-social information is an intact ability in ASD. Since the same participants completed both tasks, we are assessing whether MSI abilities are consistent across tasks for each participant.
Meeting abstract presented at VSS 2014