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Friday, September 12, 2014 - 12:00pm

IRCS Conference Room

Since Fall 2009, IRCS has collaborated with Penn's Computational Neuroscience program to present a series of lectures during the academic year.

Duje Tadin
Brain and Cognitive Science
Center for Visual Science
Department of Opthalmology
University of Rochester

Suppressive neural mechanisms: from perception to intelligence

Perception operates on an immense amount of incoming information that greatly exceeds brain's processing capacity. Because of this fundamental limitation, our perceptual efficiency is constrained by the ability to suppress irrelevant information. Here, I will present a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. We find that these suppressive mechanisms are adaptive, operating only when the sensory input is sufficiently strong to guarantee visibility. Utilizing a range of methods, we link these behavioral results with inhibitory center-surround receptive fields, such as those in cortical area MT.

What are functional roles of spatial suppression? Spatial suppression is weaker in old age and schizophrenia—as evident by paradoxically better-than-normal performance in some conditions. Moreover, these subjects also exhibit deficits in figure-ground segregation, suggesting a functional connection. In recent studies, we report direct experimental evidence for a functional link between spatial suppression and figure-ground segregation.

Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, we find that individual differences in spatial suppression of motion signals strongly predict individual variations in WAIS IQ scores (r = 0.71).