Psychophysical Determination of the Spatial Connectivity Function in a Model of Contour Salience

John S. Nafziger, Shih-Cheng Yen, and Leif H. Finkel

Institute of Neurological Sciences
Department of Bioengineering
3320 Smith Walk, 301 Hayden Hall
University of Pennsylvania
Philadelphia, PA 19104, U. S. A.

Abstract

Recently, we proposed a cortical-based model that accounts for a range of psychophysical results on contour salience [10]. In this model, cortical units are interconnected by long-range horizontal connections where the connection strength between units is defined by an inter-element spatial connectivity function. In the present work, we determine the spatial connectivity function psychophysically and compare the result to the function implemented in the original computational model. The results suggest the original product of gaussian spatial weighting function does not completely describe the psychophysical data. Rather, we find that the connectivity function is "tapered" suggesting a lack of separability between position and orientation in cortical connectivity.

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