Background light and the contrast gain of primate P and M retinal ganglion cells

Rockefeller University, New York, NY 10021-6399.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 07/1988; 85(12):4534-7. DOI: 10.1073/pnas.85.12.4534
Source: PubMed


Retinal ganglion cells projecting to the monkey lateral geniculate nucleus fall into two classes: those projecting to the magnocellular layers of the nucleus (M cells) have a higher contrast gain to luminance patterns at photopic levels of retinal illumination than those projecting to the parvocellular layers (P cells). We report here that this difference in luminance contrast gain between M and P cells is maintained at low levels of mean retinal illumination. In fact, our results suggest that in the mesopic and scotopic ranges of mean illumination, the M-cell/magnocellular pathway is the predominant conveyor of information about spatial contrast to the visual cortex.

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Available from: Ehud Kaplan, Oct 06, 2015
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    • "It is thought the M pathway dominates detection of spatial patterns in the mesopic (rod-and cone-mediated) and scotopic (rod-dominated) ranges of retinal illumination. Purpura et al. (1988) used a primate model, to show that M cells, rather than P cells were sensitive to temporally modulated sine gratings at low spatial frequency (0.6e1.6 cpd) when the mean retinal illumination was lower than 0.43 td which is equivalent to the low mesopic range in humans. D'Zmura and Lennie (1986) using a technique to isolate rod and cone systems, found that over most of the mesopic range, the spatial contrast sensitivity of the cone system was lower than that of the rod system at low spatial frequencies (1e3 cpd). "
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    ABSTRACT: Poor vision in low light is a common complaint of elderly people. This poorly understood phenomenon is likely to involve both receptoral and post receptoral mechanisms. We investigated the recovery of contrast thresholds for sine-wave gratings of low spatial frequencies and low mean luminance as a function of time in darkness after photo pigment bleaching. Thirteen subjects aged 30.4 (±10.7) years took part in the study. Contrast thresholds were measured for 15 min following almost complete photo pigment bleaching. The stimuli were achromatic sinusoidal gratings of 0.5, 1 and 2 cycle per degree (cpd) generated on a CRT monitor. They had mean luminance 0.01 cd m−2 and subtended 10° in diameter. The dynamics of the recovery at each spatial frequency were modelled using monophasic and biphasic exponential decay functions. The data were best modelled by a bi-phasic decay with a distinct transition point around 7 min after the bleach. Both phases followed an exponential decay. The time constant (mean, standard error) for the first phase was 0.35 (0.04) min while for the second phase it was 5.15 (0.27) min. This difference was statistically significant (p < 0.001). A control experiment revealed the second, slower phase was mediated by rod photoreceptors. Maximum contrast sensitivity was reached 15 min after a photic bleach. The dynamics of contrast sensitivity recovery follow two phases and these may be attributed to the cone and rod systems.
    Experimental Eye Research 07/2014; 125. DOI:10.1016/j.exer.2014.06.021 · 2.71 Impact Factor
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    • "As stimuli appear farther away from the center of the visual field, the object details fade; however, the temporal resolution of object perception improves. The peripheral retina contains a high proportion of rod photoreceptors and appears to be mainly related to the magnocellular system, which rapidly conveys low-spatial frequency (LSF) information to the dorsal stream (Baizer et al., 1991; Dacey and Petersen, 1992; Lee et al., 1997; Purpura et al., 1988; Stephen et al., 2002). To deal with these spatiotemporal resolution differences between the central and the peripheral areas of the visual field, objects are sequentially selected by either overt or covert spatial attention, i.e., with or without foveal capture (Calvo et al., 2008). "
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    • "Yet we know that visual pathways transfer several kinds of information separately. Hue is separated from luminance [10] and local contrast from global illumination [9]. Even if only one component's reconstruction quality is increased, it benefits the overall perception. "
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    ABSTRACT: The HDR tone-mapping operators were evolved rapidly during the last years. Moreover, the physiology-influenced methods were lately researched as a separate branch. Our contribution to this field is the application of hue correction according to the subjective effect referred to as the Bezold-Brücke hue shift. We introduce mathematical approach for correction of this shift. The correction is performed in a colour space given by the gamut base colours R,G,B (primaries) and white point. This approach is applied to the traditional physiology-influenced operators.
    21st European Signal Processing Conference, Marrakech, Morocco; 09/2013
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