a1 NASA-Ames Research Center, Moffett Field, California and Department of Psychology, Stanford University, Stanford, California
Simple cells in the striate cortex have been depicted as half-wave-rectified linear operators. Complex cells have been depicted as energy mechanisms, constructed from the squared sum of the outputs of quadrature pairs of linear operators. However, the linear/energy model falls short of a complete explanation of striate cell responses. In this paper, a modified version of the linear/energy model is presented in which striate cells mutually inhibit one another, effectively normalizing their responses with respect to stimulus contrast. This paper reviews experimental measurements of striate cell responses, and shows that the new model explains a significantly larger body of physiological data.
(Received April 03 1991)
(Accepted December 31 1991)
Reprint requests to: David J. Heeger, Department of Psychology, Building 420, Stanford University, Stanford, California 94305, USA.