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.
nafziger@neuroengineering.upenn.edu
syen@neuroengineering.upenn.edu
leif@neuroengineering.upenn.edu
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.
Keywords: contour; horizontal connection; psychophysics; salience