On the derivation of the foveal receptor primaries

Vos, Judith de; Walraven, P.L.

doi:10.1016/0042-6989(71)90003-4

Cited by 288 publications

(90 citation statements)

References 23 publications

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“…These estimates ranged between a factor of 1.46 to 2.36 more L as compared to AI cones in human fovea centralis. The range of values we obtained overlaps the range of earlier estimates based on modeling procedures designed to make various psychophysical data sets consistent one to another (Vos and Walraven, 1971;Walraven, 1974;Smith and Pokomy, 1975), and our mean value is virtually identical to the ratio proposed by Vos and Walraven (1971) and Walraven (1974). We have sought to verify our estimates by comparing the total numbers of L and M cones we obtained to anatomical estimates of the total numbers and densities of the cones in human fovea (Fig.…”

Section: Discussionsupporting

confidence: 48%

“…Another approach has been based on estimates deriving from curve fits required to make various sets of psychophysical data consistent one to another. Examples of this kind of analysis include Walraven's (1974) and Smith and Pokorny's (1975) estimates based on fits of the cone primaries to the luminosity function; Vos and Walraven's (1971) estimate based on compa~sons of Weber fractions for the different Stiles n mechanisms; and Walraven's (1974) estimate based on the relative heights of the spectral sensitivity functions of the cone primaries. These methods yield estimates of the relative numbers of L to J# cones which vary between 1.6 and 2.0.…”

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confidence: 99%

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The relative numbers of long-wavelength-sensitive to middle-wavelength-sensitive cones in the human fovea centralis

1989

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Abstrset-The determination of the relative numbers of different cone types in the human retina is fundamental to our understanding of visual sensitivity and color vision; yet direct measurements which provide this basic information have not previously been made for ail cone types. Here we present a model which links the detection of a test light of small dimension to the number of cones contributing to detecfon of the light. We selectively isolated either the long-wavelength-sensitive (L) or the middle-wavelengthsensitive (M) cones, by choosing combinations of wavelengths of adapting backgrounds and tests to favor detection by the cone class of interest. Our model was applied to the detection functions measured for six color normal observers to obtain estimates of the relative numbers of L to M cones. Our estimates ranged between 1.46 and 2.36 for our observers with a mean value near two L cones for every M cone in human fovea centralis. ConesHuman fovea centralis Relative numbers of L to M cones ~RODU~ONThe determination of the relative numbers of different cone types in the retina is fundamental to our understanding of human visual sensitivity and color vision, and this information would be required for any quantitative models of human vision. Direct measurements which provide this basic information have not been previously made for all cone types. There continues to be a gratifying convergence of psychophysically derived evidence from humans ~Williams et al., 1981) and anatomically derived evidence from baboon (Marc and Sperling, 1977), macaque (deMonasterio et al., 1985), and human (Ahnelt et al., 1987) on the numerosity and distribution of the shortwavelength-sensitive (S) cones in the primate retina.In the cases of the long-wavelength-sensitive (L) and middle-wavelength-sensitive (M) cones, there are no previous direct psychophysical measurements from which the relative numbers of L and M cones can be derived, and estimates based on various indirect means vary widely. To our knowledge, DeVries (1946DeVries ( , 1948 was the first to suggest that the individual variability in luminosity functions could be related to individual variability in the relative numbers of different cone types. Rushton and Baker (1964) subsequently reported that retinal densitometric measurements yielding the density of M and L cone pigments could be correlated to the flicker photometric matches between red and green lights made by their observers. Rushton and Baker's estimates, based on densitometric measurements, of the relative numbers of L to M cones in normal trichromatic observers spanned a wide range of three times more L as compared to M cones to one third as many L as compared to h4 cones. Another approach has been based on estimates deriving from curve fits required to make various sets of psychophysical data consistent one to another. Examples of this kind of analysis include Walraven's (1974) and Smith and Pokorny's (1975) estimates based on fits of the cone primaries to the luminosity function; Vos and Walraven's (1971)...

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Section: Discussionsupporting

confidence: 48%

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confidence: 99%

The relative numbers of long-wavelength-sensitive to middle-wavelength-sensitive cones in the human fovea centralis

1989

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“…Finally, (iii) the empty cones model suggests that a given class of cones contains no photopigment. While the work of Vos and Walraven [29] may support models (i) or (iii), evidence supporting the replacement model can be found in the results of several researchers [2,6,31]. This makes the photopigment substitution the most accepted model for explaining dichromacy, with genetic arguments for protanopia and deuteranopia.…”

Section: Simulating Dichromacymentioning

confidence: 93%

A Physiologically-based Model for Simulation of Color Vision Deficiency

Machado

Oliveira

Fernandes

2009

IEEE Trans. Visual. Comput. Graphics

154

126

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ReferenceProtanomaly (6 nm) Protanomaly (14 nm) Protanopia We present a physiologically-based model for simulating color perception. Our model is based on the stage theory of human color vision and is derived from data reported in electrophysiological studies. It is the first model to consistently handle normal color vision, anomalous trichromacy, and dichromacy in a unified way. We have validated the proposed model through an experimental evaluation involving groups of color vision deficient individuals and normal color vision ones. Our model can provide insights and feedback on how to improve visualization experiences for individuals with CVD. It also provides a framework for testing hypotheses about some aspects of the retinal photoreceptors in color vision deficient individuals.

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“…Since the energy per quanta is inversely proportional to wavelength (Wyszecki & Stiles, 1982), the radiant power of a light stimulus P(h) (i.e., power per unit wavelength: watts/nanometer) is proportional to N(h)/h, and so an "energy-based" sensitivity S;(h) is proportional to Q;(h)h. Given that most spectral power measurements are in "energy units," as are most tabulated cone fundamentals (Smith & Pokorny, 1975;Vos et al, 1990;Vos & Walraven, 1971), it is more convenient to compute cone excitations by using the following version of Equation 1: Normally, measurements are available only at a series of discrete wavelengths, and hence the integrations are approximated in the usual way by finite sums. Note that all published human cone sensitivities are only relative and have different scalings, independent of their specific shapes (Wyszecki & Stiles, 1982).…”

Section: D>mentioning

confidence: 99%