Abstract
Multisensory processing is often impaired in children with autism spectrum disorders (ASD) which may contribute to the social and communicative deficits that are prevalent in this population. Amelioration of multisensory deficits in adolescence has been observed for ecologically-relevant stimuli such as speech; however, this developmental recovery does not appear to generalize to the case of simple beeps and flashes, typically used in cognitive neuroscience research. Engagement of different neural processes and reduced environmental exposure to such nonsocial stimuli may lead to protracted multisensory development in neurotypical (NT) individuals, thus delaying the age at which individuals with ASD “catch up”. To determine whether recovery of multisensory deficits in ASD occurs later for ecologically-rare stimuli, we measured response times to randomly presented auditory, visual and audiovisual stimuli in over 350 participants between the ages of 6 to 40 years. By measuring the behavioral gain afforded by multisensory processing, we showed that individuals with ASD catch up to their NT peers by the mid-twenties. Computational modelling indicated that multisensory processing transitions from a default state of competition in early childhood, to one of facilitation in adulthood. This analysis also revealed developmental changes in sensory dominance that differed in individuals with ASD. Interestingly, we report that children and adolescents with ASD incurred less of a behavioral cost to switching sensory modality than their NT peers. This set of findings indicates that there is a complex interplay among the sensory systems that changes over the course of childhood, and differs in individuals with ASD.