Chromatic adaptation in red-green cone-opponent retinal ganglion cells of the macaque.
The degree of chromatic adaptation of midget ganglion cells of the parvocellular (PC) pathway was studied by measuring long-(L) to middle-wavelength (M) cone weighting at different mean chromaticities in the mid-photopic range. Cone weighting was measured using a protocol involving changing the relative phase of modulated lights, which provided an estimate independent of the level of maintained activity. The degree of adaptation at 2500 td was found to be less than complete (i.e., sub-Weberian), with the M- and L-cone contributions having slopes averaging 0.89 rather than 1.0. This is broadly consistent with the degree of light adaptation present in this cell class. The changes in maintained activity following a step change in chromaticity took tens of seconds to return toward a baseline level, but changes in cone weighting appeared much faster.
Lee
Barry B
BB
State University of New York, State College of Optometry, 33 W42nd Street, New York, NY, USA. blee@sunyopt.edu
Smith
Vivianne C
VC
Pokorny
Joel
J
Sun
Hao
H
D000221:Adaptation, Ocular / Q000502:physiology*; D000818:Animals; D003118:Color Perception / Q000502:physiology*; D008252:Macaca fascicularis; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*