The effects of photopigment depletion on brightness and threshold

Abstract Viewing an intense light depletes the store of regenerated photopigment within the receptors, thereby reducing the proportion of quanta in a subsequent stimulus that can be absorbed by the regenerated photopigment. This effect of photopigment depletion is often thought to play an insignificant role in the adaptation process. Although this appears to be true in the scotopic system, Rushton's densitometry measurements of the bleaching and regeneration of cone pigments are used here to show that in the photopic system photopigment depletion plays a substantial role in determining (a) darkadaptation thresholds, (b) the brightness of steady lights, (c) increment thresholds obtained against continuous backgrounds, and (d) simultaneous brightness contrast at high test- and inducing-field intensities. The effects of photopigment depletion on brightness were examined using a modified version of Craik's (1940) experiment.

[1]  S. Hecht,et al.  RODS, CONES, AND THE CHEMICAL BASIS OF VISION , 1937 .

[2]  W A RUSHTON,et al.  Cone pigment kinetics in the protanope , 1963, The Journal of physiology.

[3]  W. Geisler.  Adaptation, afterimages and cone saturation , 1978, Vision Research.

[4]  E. G. Heinemann,et al.  The relation of apparent brightness to the theshold for differences in luminance. , 1961, Journal of experimental psychology.

[5]  B. H. Crawford.  Visual adaptation in relation to brief conditioning stimuli , 1947, Proceedings of the Royal Society of London. Series B - Biological Sciences.

[6]  E N Pugh,et al.  The density and photosensitivity of human rhodopsin in the living retina , 1974, The Journal of physiology.

[7]  W. Stiles,et al.  The colour change of monochromatic light with retinal angle of incidence. , 1961, The Optometric weekly.

[8]  R. Weale.  Photo-chemical changes in the dark-adapting human retina , 1962 .

[9]  W A RUSHTON,et al.  Cone pigment kinetics in the deuteranope , 1965, The Journal of physiology.

[10]  H. Barlow.  Temporal and spatial summation in human vision at different background intensities , 1958, The Journal of physiology.

[11]  P E King-Smith,et al.  The optical density of erythrolabe determined by retinal densitometry using the self‐screening method , 1973, The Journal of physiology.

[12]  W. Rushton.  Rhodopsin measurement and dark‐adaptation in a subject deficient in cone vision , 1961, The Journal of physiology.

[13]  R M BOYNTON,et al.  Visual responses to equally bright stimuli of unequal luminance. , 1962, Journal of the Optical Society of America.

[14]  Eric G. Heinemann,et al.  Simultaneous Brightness Induction , 1972 .

[15]  D. D. Michaels.  The nature of the photoreceptor process. , 1956, American journal of optometry and archives of American Academy of Optometry.

[16]  K. J. W. Craik,et al.  The effect of adaptation on subjective brightness , 1940, Proceedings of the Royal Society of London. Series B - Biological Sciences.

[17]  W A Rushton,et al.  Signals from cones , 1970, The Journal of physiology.

[18]  T. Cornsweet.  Changes in the appearance of stimuli of very high luminance. , 1962, Psychological review.

[19]  Michaels Dd,et al.  The nature of the photoreceptor process. , 1956 .

[20]  W. A. H. Rushton,et al.  FLASH PHOTOLYSIS IN HUMAN CONES * , 1964 .

[21]  London,et al.  Light, Colour and Vision , 1969 .

[22]  W. Rushton,et al.  Bleaching and regeneration of cone pigments in man. , 1968, Vision research.

[23]  H B Barlow,et al.  Dark-adaptation: a new hypothesis. , 1964, Vision research.

[24]  M. Hollins,et al.  Dark Adaptation and Visual Pigment Regeneration in Human Cones , 1973, The Journal of general physiology.

[25]  R. M. Boynton,et al.  Visual Adaptation in Monkey Cones: Recordings of Late Receptor Potentials , 1970, Science.

[26]  W A RUSHTON,et al.  Measurement of the scotopic pigment in the living human eye , 1955, The Journal of physiology.

[27]  E. G. Heinemann,et al.  Simultaneous brightness induction as a function of inducing and test-field luminances. , 1955, Journal of experimental psychology.

[28]  W A RUSHTON,et al.  The density of chlorolabe in the foveal cones of the protanope , 1963, The Journal of physiology.

[29]  G. Brindley.  A Photochemical Reaction in the Human Retina , 1955 .