Abstract

Electrophysiological and anatomical evidence from monkeys indicates that the striate cortex is broken up into some 1500 modules, each containing cells which process information from a limited part of the visual field which overlaps to a varying extent (depending on the cell’s peak spatial frequency) with the cells in neighboring modules. Within each module is a systematic columnar arrangement of cells tuned to various 2-D spatial frequency regions (orientation and spatial frequency). The various cells within a foveally related module cover at least a 5-octave spatial frequency range. With increasing eccentricity, the center of the band shifts to lower spatial frequencies, and the octave range may also narrow. The narrowly tuned simple cells within each module have multiple, mutually antagonistic subregions within their receptive fields and an overall rf shape which approximates a 2-D Gabor (a sinusoid tapered in x and y by a Gaussian). Each narrowly tuned simple and complex cell is optimally activated by patterns containing power within its particular 2-D spatial frequency region in its particular limited part of the visual field; the simple cells are also selective for the phase of the pattern, but the complex cells are not.

© 1985 Optical Society of America