Poster F96, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Atypical multisensory temporal integration in posterior superior temporal cortex may underlie language, social, and perceptual deficits in autism spectrum disorders
Naail A. Khan1, Stephanie M. Lavoie1, Ryan A. Stevenson2, Morgan D. Barense3, Mark T. Wallace4, James M. Bebko1, W. Dale Stevens1; 1York University, Toronto, 2University of Western Ontario, 3University of Toronto, 4Vanderbilt University
Individuals with autism spectrum disorders (ASD) exhibit multisensory processing deficits (e.g., atypical temporal integration of auditory-visual information), which may underlie downstream deficits in language, social-cognitive, and perceptual processing. While some evidence suggests that multisensory processing deficits in ASD are language-specific, previous findings are equivocal. Posterior superior temporal cortex (pSTC), a brain region showing anatomical and functional differences in ASD, plays a critical role in auditory-visual temporal integration, as well as linguistic and social processing. However, few studies have directly investigated the neural correlates of multisensory integration in ASD. We recently proposed a novel “temporal synchrony method” for localizing multisensory regions in individual participants using fMRI. Here, we used this method to localize multisensory pSTC regions bilaterally in typically developing (TD: n=17) individuals and those with ASD (n=15). We compared activation in these regions to temporally synchronous vs. asynchronous auditory-visual stimuli (short video clips) with social linguistic (person talking), social non-linguistic (person making non-linguistic sounds), and non-social non-linguistic (marble course) content. The large majority of TD participants showed greater activation for synchronous than asynchronous stimuli in pSTC across hemispheres and content-domains, though most prominently so in the left hemisphere for linguistic content. Critically, individuals with ASD showed a complete reversal of this pattern, with the majority showing more activity for asynchronous than synchronous stimuli across hemispheres and content domains. Our results suggest that 1) atypical multisensory processing in ASD is not language-specific; 2) Multisensory pSTC may be a viable target for neurointervention strategies, such as neurofeedback training and noninvasive brain stimulation.
Topic Area: PERCEPTION & ACTION: Multisensory