Revisiting spatial vision: toward a unifying model

We report contrast detection, contrast increment, contrast masking, orienta tion discrimination, and spatial frequency discrimination thresholds for sp atially localized stimuli at 4 degrees of eccentricity. Our stimulus geomet ry emphasizes interactions among overlapping visual filters and differs fro m that used in previous threshold measurements, which also admits interacti ons among distant filters. We quantitatively account for all measurements b y simulating a small population of overlapping visual filters interacting t hrough divisive inhibition. We depart from previous models of this kind in the parameters of divisive inhibition and in using a statistically efficien t decision stage based on Fisher information. The success of this unified a ccount suggests that, contrary to Bowne [Vision Res.30, 449 (1990)], spatia l vision thresholds reflect a single level of processing, perhaps as early as primary visual cortex. (C) 2000 Optical Society of America [S0740-3232(0 0)02311-5].