The new DSM-5 diagnostic criteria for autism spectrum disorders (ASDs) include sensory disturbances in addition to the well-established language, communication, and social deficits. One sensory disturbance seen in ASD is an impaired ability to integrate multisensory information into a unified percept. This may arise from an underlying impairment in which individuals with ASD have difficulty perceiving the temporal relationship between cross-modal inputs, an important cue for multisensory integration. Such impairments in multisensory processing may cascade into higher-level deficits, impairing day-to-day functioning on tasks, such as speech perception.
To investigate multisensory temporal processing deficits in ASD and their links to speech processing, the current study mapped performance on a number of multisensory temporal tasks (with both simple and complex stimuli) onto the ability of individuals with ASD to perceptually bind audiovisual speech signals. High-functioning children with ASD were compared with a group of typically developing children. Performance on the multisensory temporal tasks varied with stimulus complexity for both groups; less precise temporal processing was observed with increasing stimulus complexity. Notably, individuals with ASD showed a speech-specific deficit in multisensory temporal processing. Most importantly, the strength of perceptual binding of audiovisual speech observed in individuals with ASD was strongly related to their low-level multisensory temporal processing abilities. Collectively, the results represent the first to illustrate links between multisensory temporal function and speech processing in ASD, strongly suggesting that deficits in low-level sensory processing may cascade into higher-order domains, such as language and communication.
Ryan A. Stevenson, Justin K. Siemann, Brittany C. Schneider, Haley E. Eberly, Tiffany G. Woynaroski, Stephen M. Camarata, and Mark T. Wallace
Author contributions: R.A.S., S.M.C., and M.T.W. designed research; R.A.S., J.K.S., B.C.S., and H.E.E. performed research; R.A.S., J.K.S., T.G.W., S.M.C., and M.T.W. contributed unpublished reagents/analytic tools; R.A.S. and J.K.S. analyzed data; R.A.S., J.K.S., T.G.W., and M.T.W. wrote the paper.The Journal of Neuroscience, 15 January 2014, 34(3): 691-697; doi: 10.1523/JNEUROSCI.3615-13.2014
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