This proposal is directed toward the study of normal color vision, and to the assessment of the color defects which occur in individuals with stationary, hereditary color defects and those which occur in various retinal and choroidal disease states. Psychophysical methods will be used to study heterochromatic sensitivity, color matching, and spectral sensitivity of the cone mechanisms. These studies are designed to reveal the nature of the retinal cone mosaic, including the numbers and types of photoreceptors in observers with normal and abnormal color vision. Psychophysical and electroretinographic techniques will allow basic studies of the short wavelength sensitive (SWS) cone mechanism in color normal individuals and in patients with retinal disease. Studies of temporal modulation sensitivity using heterochromatic modulation photometry will be performed with the aim of separating the effects of radiance, chromaticity and temporal frequency. Retinal densitometry will be used to study cone visual pigment kinetics in color normal and color defective observers and will evaluate the feasibility of studying cone visual pigment kinetics in patients with acquired macular disorders. The development and evaluation of protocols for testing patients with eye disease will be continued.
The aim i s to develop easily-performed and rapid tests which give specific information concerning visual function in eye disease. In addition to empirical studies, models of normal and abnormal color vision will continue to be developed. The theoretical approach is based in the question: to what extent can established biological or physical phenomena explain the data of color vision? This approach is one which allows us to examine the plausibility of various hypotheses which are not subject to direct experimental evaluation.
|Pokorny, Joel; Smith, Vivianne C; Xu, Jun (2012) Quantal and non-quantal color matches: failure of Grassmann's laws at short wavelengths. J Opt Soc Am A Opt Image Sci Vis 29:A324-36|
|Cao, Dingcai; Pokorny, Joel (2010) Rod and cone contrast gains derived from reaction time distribution modeling. J Vis 10:11.1-15|
|Cao, Dingcai; Zele, Andrew J; Smith, Vivianne C et al. (2008) S-cone discrimination for stimuli with spatial and temporal chromatic contrast. Vis Neurosci 25:349-54|
|Cao, Dingcai; Zele, Andrew J; Pokorny, Joel (2008) Chromatic discrimination in the presence of incremental and decremental rod pedestals. Vis Neurosci 25:399-404|
|Zele, Andrew J; Cao, Dingcai; Pokorny, Joel (2008) Rod-cone interactions and the temporal impulse response of the cone pathway. Vision Res 48:2593-8|
|Lee, Barry B; Smith, Vivianne C; Pokorny, Joel et al. (2008) Chromatic adaptation in red-green cone-opponent retinal ganglion cells of the macaque. Vision Res 48:2625-32|
|Smith, Vivianne C; Pokorny, Joel; Lee, Barry B et al. (2008) Sequential processing in vision: The interaction of sensitivity regulation and temporal dynamics. Vision Res 48:2649-56|
|Pokorny, Joel; Lutze, Margaret; Cao, Dingcai et al. (2008) The color of night: surface color categorization by color defective observers under dim illuminations. Vis Neurosci 25:475-80|
|Cao, Dingcai; Pokorny, Joel; Smith, Vivianne C et al. (2008) Rod contributions to color perception: linear with rod contrast. Vision Res 48:2586-92|
|Gamlin, Paul D R; McDougal, David H; Pokorny, Joel et al. (2007) Human and macaque pupil responses driven by melanopsin-containing retinal ganglion cells. Vision Res 47:946-54|
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