Advances in Photoreception Proceedings of a Symposium on Frontiers of Visual Science (1990) / Chapter Skim
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Photosensitivity of Primate Photoreceptors
Photosensitivity of Primate Photoreceptors
Pages 31-38
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From page 31... ...
These spectral functions have been determined in rods and cones of macaque and human retinas by recording their photocurrents. The spectra obtained in these experiments provide the receptoral basis for human colormatching functions and luminosity functions.
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From page 32... ...
When plotted on a normalized wavenumber scale, where wavenumber is divided by the wavenumber of maximum absorption, the absorption spectra of the four macaque photoreceptors have a common shape. The action spectra shown here confirm this observation, although the normalized rod spectrum is slightly broader than that of the cones.
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From page 33... ...
, 20 green cones God, 16 red cones (o) , and 10 rods God, as a function of wavenumber.
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From page 34... ...
Specifically, the effects of light absorption by the human lens and macular pigment were taken into account as well as photopigment self-screening within the cone outer segments in the psychophysical experiment. The forms of the preretinal absorption spectra were taken from Wyszecki and Stiles (1982~; self-screening was assumed to follow Beer's Law.
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From page 35... ...
The smooth curves show the relative amount of light required of the three pnmanes to match a test light of unit intensity as a function of the wavelength of the test light (Stiles and Burch, 1955~. The points plot the predicted results based on the spectral sensitivity functions of the macaque cones in Figure 1 after co~Tectio~i for absorption by the lens and macular pigment and photopigment self-screening.
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From page 36... ...
were chosen to give the best fit between the points and the curve. A good match was obtained between the two luminosity functions and the corresponding physiological results, consistent with the idea that the scotopic function is set by the filtered rod spectrum and that the photopic function is determined by the summed activity of the red and green cones.
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From page 37... ...
The continuous curve is the photopic luminosity function of Vos (1978~; the dashed curve is the scotopic luminosity function of Crawford (1949~. The symbols plot the correlated spectral sensitivities of the macaque rods (~)
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From page 38... ...
Burch 1955 Interim report to the Commission Internationale de l'Eclairage, Zurich, 1955, on the National Physical Laborato~y's investigation of colour-matching (1955~. Optica Acta 2:168 181.
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