Norma Graham
Columbia University
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Primary Section: 52, Psychological and Cognitive Sciences Secondary Section: 28, Systems Neuroscience Membership Type:
Member
(elected 1998)
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Research Interests
My research is on visual perception, more specifically, on low-level processes involved in pattern and form vision. My early work helped develop the concept of multiple channels where different channels are sensitive to different ranges of spatial frequency. (A pattern of narrow stripes or fine-grained texture contains predominantly high spatial frequencies. A pattern of large-sized elements contains predominantly low spatial frequencies. The physiological substrate for these spatial-frequency channels may be neurons in the lowest levels of visual cortex.) My recent research is on the effortless perceptual segregation of different visual textures. Differences in visual texture distinguish meaningful regions in most natural scenes. Laboratory studies of texture segregation may provide insight into an important process in everyday perception-a process that segments a visual scene into regions allowing other processes to do more efficient computations within regions. Explaining perceived texture segregation requires not only the linear transformations done by ordinary spatial-frequency channels but also nonlinear processes such as complex (non-Fourier) channels and interchannel inhibition or normalization.
