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Contrast (vision)

About: Contrast (vision) is a research topic. Over the lifetime, 10379 publications have been published within this topic receiving 221480 citations.


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Journal ArticleDOI
TL;DR: The significant decline in sensitivity for low contrast, high temporal events in AD patients is consistent with reports of cell loss at the retinal and cortical levels of the magnocellular (M) channel in AD.
Abstract: Spatial contrast sensitivity was evaluated in normal elderly adults and a group with probable Alzheimer's disease (AD) in three sessions over a 1-year period. There was evidence of a reduction over 1 year in contrast sensitivity for static, high spatial frequencies in both groups of subjects. A striking difference between the subject groups was observed in their response to flickered stimuli. Although normal elderly adults yielded good stability in sensitivity for both static and flickered spatial frequencies over the 1 year, AD patients experienced a significant decline in response to flickered (7.5 Hz) stimuli. The significant decline in sensitivity for low contrast, high temporal events in AD patients is consistent with reports of cell loss at the retinal and cortical levels of the magnocellular (M) channel in AD. Thus, the spatial contrast sensitivity change in AD may reflect a more rapid loss of cells specifically in the M channel over a 1-year period.

74 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the neural basis of these two complementary behavioural effects using functional magnetic resonance imaging to measure how voluntary blinking affected cortical responses to visual stimulation, and found that both suppression in lateral occipital and activation in medial parieto-occipital cortex were greater during blinks than during matched external darkenings of the visual scene, suggesting that they result from an extra retinal signal associated with the blink motor command.

74 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the influence of interocular sensitivity difference on binocular contrast sensitivity in amblyopia and found that the interocular difference produced binocular summation, the magnitude of which decreased as the difference between the two eyes increased.
Abstract: The monocular contrast sensitivity loss in amblyopia is well documented. We investigated the influence of interocular sensitivity difference on binocular contrast sensitivity in amblyopia. Monocular and binocular contrast sensitivity functions of six amblyopes (three strabismic and three anisometropic) were measured. The monocular contrast sensitivity loss depended on the type of amblyope. Anisometropic amblyopes generally showed high frequency losses. Strabismic amblyopes showed losses at both low and high spatial frequencies. Binocular performance was assessed in terms of binocular ratios (binocular/non-amblyopic). A binocular ratio greater than 1 indicates binocular summation (binocular > monocular) while a ratio less than 1 shows binocular inhibition (binocular < monocular). In all subjects, the binocular ratio depended on the difference between the amblyopic and the non-amblyopic eye. Minimal interocular difference produced binocular summation, the magnitude of which decreased as the difference between the two eyes increased. Further increases in the monocular difference produced binocular inhibition. Anisometropic amblyopes showed a greater degree of binocular summation at low spatial frequencies compared to strabismic amblyopes. Both types of amblyopes showed binocular inhibition at high spatial frequencies. Clinical implications of binocular summation and inhibition in amblyopia are discussed.

74 citations

Journal ArticleDOI
TL;DR: The results suggest that the relatively slow development of the chromatic tCSF in infants may reflect immature chromatic responses in the P pathway and/or reliance on Chromatic responses originating in the M pathway.

73 citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20231,864
20223,760
2021413
2020329
2019354