Abstract
Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity and communication, as well as by repetitive behaviors and restricted interests. Unusual responses to sensory input and disruptions in the processing of both unisensory and multisensory stimuli also have been reported frequently. However, the specific aspects of sensory processing that are disrupted in ASD have yet to be fully elucidated. Recent published work has shown that children with ASD can integrate low-level audiovisual stimuli, but do so over an extended range of time when compared with typically developing (TD) children. However, the possible contributions of altered unisensory temporal processes to the demonstrated changes in multisensory function are yet unknown. In the current study, unisensory temporal acuity was measured by determining individual thresholds on visual and auditory temporal order judgment (TOJ) tasks, and multisensory temporal function was assessed through a cross-modal version of the TOJ task. Whereas no differences in thresholds for the visual TOJ task were seen between children with ASD and TD, thresholds were higher in ASD on the auditory TOJ task, providing preliminary evidence for impairment in auditory temporal processing. On the multisensory TOJ task, children with ASD showed performance improvements over a wider range of temporal intervals than TD children, reinforcing prior work showing an extended temporal window of multisensory integration in ASD. These findings contribute to a better understanding of basic sensory processing differences, which may be critical for understanding more complex social and cognitive deficits in ASD, and ultimately may contribute to more effective diagnostic and interventional strategies.
Highlights
Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity, communication, and behavioral flexibility that emerge in the first few years of life (American Psychiatric Association, 2000)
Performance on the Unisensory temporal order judgment (TOJ) Tasks To determine whether visual and auditory temporal processing differ in children with ASD as compared to children with typically developing (TD), we determined the threshold stimulus onset asynchronies (SOAs) values at which participants could report which of two stimuli occurred first at approximately 75% accuracy
For the auditory TOJ task, data from 15 children with ASD were excluded from analyses due to non-compliance, inattention, or inability to comprehend the task (n = 4), or inability to verify the auditory threshold from the confirmation procedure
Summary
Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity, communication, and behavioral flexibility that emerge in the first few years of life (American Psychiatric Association, 2000). Reports of abnormal sensory function that span the visual, auditory, gustatory, and tactile domains reinforce the “multisensory” nature of sensory processing alterations in ASD (for review, see Rogers and Ozonoff, 2005), and emerging evidence suggests that abnormalities extend to the selective integration of information across the different sensory modalities (i.e., multisensory integration – see Iarocci and McDonald, 2006). Evidence for deficits in sensory (and multisensory) processing is abundant in the ASD literature, there are a number of reports detailing enhanced perceptual capabilities in response to specific sensory stimuli. In an effort to reconcile these findings showing both impaired and enhanced sensory function in ASD, it has been suggested that perceptual abilities may depend on the nature and complexity of the sensory stimuli, with impairments characterizing responses to more complex stimuli and enhancements seen more often with simple stimuli (Samson et al, 2006; Mongillo et al, 2008). In the same study, adolescents and adults with autism were found to show superior orientation discrimination of Frontiers in Integrative Neuroscience www.frontiersin.org
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
