title: Small field tritanopia in the peripheral retina.
abstract: If stimuli are made sufficiently small, color-normal individuals report a loss in hue perception, in particular a decrease in the perception of green, in both the fovea and peripheral retina. This effect is referred to as small field tritanopia. It is not clear, however, how rod input may alter the dynamics of small field tritanopia in the peripheral retina. This paper looks at peripheral hue-naming data obtained for small stimuli at mesopic and photopic retinal illuminances under conditions that minimize (bleach) and maximize (no bleach) rod contribution. The data show that attenuation in the perception of green occurs with larger stimuli in the no-bleach condition than in the bleach condition. As retinal illuminance increases, the stimulus size that elicits small field tritanopia decreases, but the stimulus size is still larger under the no-bleach condition. Small field tritanopia in both the bleach and no-bleach conditions may be related to short-wavelength-sensitive (S) cone activity and its potential role in the mediation of the perception of green. The differences in stimulus size for small field tritanopia may be explained by rod input into the magnocellular and koniocellular pathways, which compromises the strength of the chromatic signals and creates a differential loss in the perception of green as compared to the other elemental hues.
authors.forename: Vicki J
authors.initials: VJ
authors.lastname: Volbrecht
mesh_terms: D000328:Adult; D003118:Color Perception; D003117:Color Vision Defects / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D055255:Mesopic Vision; D008875:Middle Aged; D012160:Retina / Q000503:physiopathology*; D014794:Visual Fields