PROJECT SUMMARY/ABSTRACT Autism spectrum disorder (ASD) is a complex disorder of brain development characterized by difficulties in social interaction and communication and the presence of restricted and repetitive behaviors and is often accompanied by disruptions of sensory and perceptual processing. Altered sensory and perceptual processing leads to a range of individual experiences including heightened and dampened sensory reactions that can profoundly affect quality of life. Despite the prominence of sensory and perceptual symptoms in ASD there is no unifying explanation for their etiology. The central premise of this proposal is that the sensory and perceptual processing differences that occur in ASD derive from differences in attention. Specifically, we will test the hypothesis that spatial- and feature-based attention is more narrowly focused and that rapid oscillations of attention occur at a slower rate in people with ASD. Our proposal employs computational models of visual cortical responses in combination with psychophysical and brain imaging measures of neural responses. Overall, our results will significantly advance understanding of the neural and computational basis of sensory and perceptual changes in ASD.