Document Detail

Variation in color matching and discrimination among deuteranomalous trichromats: theoretical implications of small differences in photopigments.
MedLine Citation:
PMID:  7483302     Owner:  NLM     Status:  MEDLINE    
Individual differences in abnormal color vision are well known. A fundamental unresolved problem is the great variation in color vision even among those classified as having the same color-vision defect. Several physiological hypotheses have been proposed to account for this variation but little consideration has been given to how (and how much) color matching and discrimination are affected by the posited physiological mechanisms. Advances in molecular genetics have renewed interest in this problem, which is at the foundation of the relation between genotype and phenotype. We report here theoretical Rayleigh ranges (chromatic discrimination) and quantal matches for deuteranomalous trichromats with photopigments in the red/green range that vary in their separation and optical density. The results show there is relatively little loss of discrimination with pigments of normal optical density separated by as little as 2-3 nm. With pigments separated by 4 nm or less, however, optical density can strongly influence discrimination when varied independently in the two types of cone. Moderately lower (or higher) optical density in only one cone-type affects discrimination by altering the shape of the cone's relative spectral sensitivity function. The lack of correlation between Rayleigh-match midpoint and range, which is reported in the literature, may be accounted for by independent variation in pigment separation and optical density.
J C He; S K Shevell
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Vision research     Volume:  35     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  1995 Sep 
Date Detail:
Created Date:  1995-12-12     Completed Date:  1995-12-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  2579-88     Citation Subset:  IM    
Department of Psychology, University of Chicago, IL 60637, USA.
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MeSH Terms
Color Perception / physiology*
Color Vision Defects / physiopathology*
Discrimination (Psychology) / physiology
Models, Biological
Retinal Pigments / physiology*
Grant Support
Reg. No./Substance:
0/Retinal Pigments

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