Scott Murray, PhD
Professor, Department of Psychology, University of Washington
Monday, April 19, 2021
11:10 am - 12:30 pm
Using the visual system to study autism spectrum disorder
Autism is defined by difficulties in social interactions and repetitive behaviors and restricted interests – behavioral dimensions that would appear to be unrelated to vision. However, changes in visual perception in individuals with autism are well-known and can be substantial. We hypothesized that visual perception changes may reflect alterations in canonical cortical computations such as divisive normalization and basic neural circuit properties such as excitation/inhibition balance. Using a multi-method approach including fMRI, magnetic resonance spectroscopy, psychophysics, pharmacology, and computational modeling, we leveraged well-characterized properties of the human visual system – such as surround suppression and adaptation – to identify how cortical neural processing is altered in autism. Our experiments found no evidence in favor of a prominent hypothesis that autism is associated with an increase in cortical excitation-inhibition balance. Instead, our results suggest that autism is associated with a spatially narrower ‘window of attention’. This spatially narrower top-down gain can potentially explain the often inconsistent and divergent findings observed in autism perception research.