This research project consists of a series of electrophysiological and psychophysical studies of certain aspects of spatial vision. In studies of the striate cortex (cortical area V1), the investigators propose to examine the arrangement of cells tuned to various orientations and spatial frequencies in relation to the cytochrome oxidase blobs marking the cortical modules. The investigators also plan to examine how the spatial frequency tuning and phase-specificity of striate cells vary with eccentricity. In studies of cells in the second cortical visual area (V2), it will be determined how these cells respond to simple patterns which well characterize V1 units, and to somewhat more complex patterns, to explore possible transformations occurring in information processing at this level. In the psychophysical experiments, the investigators will examine certain aspects of human ability to localize patterns independent of the characteristics of the patterns, and to study some problems of pattern discrimination which depend on ratio judgments. Both of these problem areas were chosen to explore in perceptual experiments certain issues which have arisen in considering the possible roles of cells in cortical areas V1 and V2. The results of this research project will contribute important information to our knowledge of visual information processing by the brain.
