In intraparietal sulcus, conversely, in this particular task we see supranormal attentional activation in autism. Activation scores in left intraparietal sulcus are significantly greater than normal, and in those subjects in our sample who have the most severe symptoms we also see a this effect in right parietal sulcus. We conceptualise this heightened response in intraparietal sulcus as a reflection of a compensatory effort to suppress the irrelevant signal that has made it through because of dysfunctional early filtering.

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`fMRI Evidence for Generalised Arousal as a Substitute for Early Selection in Autism during Conditions of Shifting Visual Spatial Attention', Matthew Belmonte, 10 November 2001