Neural Mechanisms for Sensory Features in Autism

Caregivers, educators and practitioners have long taken note of prevalent sensory features, such as hyper- and hyporesponsiveness to sensory stimuli and highly focused perceptual processing styles, that are shared by many people with autism. While the vast majority of autism research has proceeded using a “top-down” strategy (beginning with hypotheses related to the complex social-communication behaviors that define the disorder), a growing contingent of researchers have begun to address autism from the “bottom-up.” A bottom-up approach starts with the premise that social-communication behaviors depend on complex and highly specialized sensory and perceptual functions that may also be compromised at lower levels of processing in persons with autism. Investigation of simple sensation and perception is a natural fit for neurophysiology and functional brain imaging techniques, which have already uncovered important clues to the disorder. This presentation will describe plausible neural mechanisms underlying myriad sensory features in autism and their relationship to core features. Recent findings from neurophysiological and fMRI methods will be discussed to highlight emergent themes such as: enhanced processing of simple auditory, tactile, and visual stimuli; specific deficits in processing complex non-social sensory stimuli; and aberrant connectivity within and between brain regions as potential neural substrates of sensory features seen in autism. The convergence of these findings with fMRI studies of more complex social stimuli such as speech and faces will help to characterize various strengths and deficits along the continuum of sensory and perceptual processing complexity. Future directions for translational research that connects our understanding of neural mechanisms to clinical assessment and intervention for sensory features in autism will be discussed.