Lateral interactions in primary visual cortex: a model bridging physiology and psychophysics
Recent physiological studies show that the spatial context of visual stimuli enhances the response of cells in primary visual cortex to weak stimuli and suppresses the response to strong stimuli. A model of orientation-tuned neurons was constructed to explore the role of lateral cortical connections in this dual effect. The differential effect of excitatory and inhibitory current and noise conveyed by the lateral connections explains the physiological results as well as the psychophysics of pop-out and contour completion. Exploiting the model's property of stochastic resonance, the visual context changes the model's intrinsic input variability to enhance the detection of weak signals.
Received 3 April 1995 ; accepted 27 July 1995. Supported by the Howard Hughes Medical Institute, the National Institutes of Mental Health (grants MH47566 and MH45156), the Office of Naval Research, the Air Force Office of Scientific Research, the National Science Foundation, the Center for Neuromorphic Systems Engineering as a part of the National Science Foundation Engineering Research Center Program, and by the Office of Strategic Technology of the California Trade and Commerce Agency. We thank J. Knierim, K. Grieve, F. Worg6tter, and C. Koch for discussions; A. Zador, U. Polat, and M. Sur for access to unpublished data; G. Blasdel for providing the orientation map underlying Fig. 1; and C. Koch and J. McClelland for a stimulating work environment.