Computational Neuroimaging: Cortical Color Responses in Human and Macaque

Brian A. Wandell
Psychology Department
Stanford University
Stanford, CA 94305

Abstract

Color has been an excellent model system for developing a quantitative understanding of visual perception. We understand a great deal about the physical signal that initiates color perception, and this knowledge has led to a precise understanding of the retinal encoding of the color signal. This understanding, in turn, is the basis of quantitative models of color matching (a key element of all color technologies), and the neural origins of several key properties of color appearance.

Our group is working to extend quantitative models of the retinal encoding of color information and to explain color responses in identified visual areas (V1, V2, V3, V3A and V4) in human and monkey visual cortex. Color in cortex has been a contentious area of research; in this talk I will review and evaluate competing claims about the organization of visual areas in a portion of human visual cortex that is essential for color vision. I will take a side.

Then, I will describe novel color measurements in human and macaque visual cortex. In both species, the color responses are widespread, but inhomogeneous. Within V1, V2 and V3, the position of the strongest color responses depends on the spatial structure of the stimulus. Across dorsal and ventral visual areas, color responses appear to follow different principles. These differences in ventral and dorsal cortex responses suggest some computational principles about the role of color in different cortical pathways.

Joint work with Alyssa Brewer, Junjie Liu, and Alex Wade.

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