Red-green vs. blue-yellow spatio-temporal contrast sensitivity across the visual field

We measured contrast sensitivity (CS) to sinusoidal spatio-temporal patterns isolating the red-green and blue-yellow mechanisms, at 21 locations in the visual field (including the fovea). These measurements complete the available data for the red-green mechanism at fovea and for both mechanisms outside fovea with non-stationary patterns. Chromatic detection surfaces are low-pass at fovea and CS decreases with eccentricity at a rate that depends on the spatial and temporal frequencies. Our results confirm that, in general, sensitivities decrease with eccentricity at different rates for stationary red-green and blue-yellow patterns at each point of the spatio-temporal domain and that the chromatic detection surfaces are still low-pass at each spatial location. The results suggest some superiority of the temporal visual field for both mechanisms. Surprisingly the spatial region with maximum sensitivity for blue-yellow patterns for stimuli in the low-spatial–high temporal corner of the spatio-temporal domain ...