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Human vision starts with the activation of rod photoreceptors in dim light and short (S)-, medium (M)-, and long (L)- wavelength-sensitive cone photoreceptors in daylight. Recently a parallel, non-rod, non-cone photoreceptive pathway, arising from a population of retinal ganglion cells, was discovered in nocturnal rodents. These ganglion cells express the(More)
We measured the sensitivity of macaque ganglion cells to luminance and chromatic sinusoidal modulation. Phasic ganglion cells of the magnocellular pathway (M-pathway) were the more sensitive to luminance modulation, and tonic ganglion cells of the parvocellular pathway (P-pathway) were more sensitive to chromatic modulation. With decreasing retinal(More)
Melanopsin, a novel photopigment, has recently been localized to a population of retinal ganglion cells that display inherent photosensitivity. During continuous light and following light offset, primates are known to exhibit sustained pupilloconstriction responses that resemble closely the photoresponses of intrinsically-photoreceptive ganglion cells. We(More)
Physiological data have revealed characteristic contrast gain and temporal integration signatures of the magnocellular (MC) and the parvocellular (PC) pathways. The goal in this study was to find psychophysical correlates of these signatures. Psychophysical forced-choice, luminance pedestal discrimination data were collected with a stimulus-surround(More)
The chromatic dimensions of human color vision have a neural basis in the retina. Ganglion cells, the output neurons of the retina, exhibit spectral opponency; they are excited by some wavelengths and inhibited by others. The hypothesis that the opponent circuitry emerges from selective connections between horizontal cell interneurons and cone(More)
1. We measured the response of macaque ganglion cells to sinusoidally modulated red and green lights as the relative phase, theta, of the lights was varied. 2. At low frequencies, red-green ganglion cells of the parvocellular (PC-) pathway with opponent inputs from middle-wavelength sensitive (M-) and long-wavelength sensitive (L-) cones were minimally(More)
We studied temporal processing of chromatic and luminance perturbations of a 600-nm field, measuring both modulation sensitivity (sinusoidal frequencies from 0.25 to 40 Hz) and pulse-detection thresholds (pulse durations from 5 to 2560 msec) for mean luminances of 0.9 to 900 Td and field sizes of 0.5 degrees to 8 degrees. Chromatic stimuli were produced by(More)
We measured responses of macaque retinal ganglion cells to different periodic waveforms (sinusoidal, square, rapid-on and rapid-off sawtooth waveforms) for both luminance and equiluminant chromatic modulation. We analyzed the responses with a peak-to-trough detector. At low frequencies, on-center and off-center magnocellular (MC-) pathway cells showed a(More)
The strength of rod inputs to ganglion cells was assessed in the macaque retina at retinal positions within 3-15 deg eccentricity. The experimental paradigm used temporally modulated heterochromatic lights whose relative phase was varied. This paradigm provided a sensitive test to detect rod input. In parvocellular (PC) pathway cells, the gain of the(More)