Abstract
It is generally accepted that as stimulus size increases outside the fovea, color perception becomes more fovea-like. The underlying assumption is that foveal color perception is more saturated than peripheral color perception possibly due likely due to the influence of rods in the periphery. We created Uniform Appearance Diagrams (UADs) from color naming data (440-660 nm) obtained in the fovea with a 1° stimulus and in the peripheral retina (10° retinal eccentricity) under bleach (minimal rod input) and no-bleach (maximal rod input) conditions. The stimulus size in the peripheral retina varied from 1° to 5° contingent on the experimental condition (i.e., bleach condition, retinal location, and retinal illuminance). When the foveal UAD was compared to the peripheral UADs, it was found that under some conditions, contrary to generally held assumptions, stimuli at the middle- and longer-wavelengths appeared more saturated in the peripheral retina, under both bleach and no-bleach conditions, than in the fovea. This result is surprising given that rods are known to desaturate stimuli, especially in the middle wavelengths. In addition to well documented rod input differences, perhaps these results demonstrate cone input into the chromatic and achromatic pathways also differs between the fovea and the peripheral retina.
Meeting abstract presented at OSA Fall Vision 2012