Increment threshold and purity discrimination spectral sensitivities of X-chromosome-linked color-defective observers


The goal of the study was to evaluate spectral opponency in nine X-chromosome-linked color-defective observers. The tasks included increment threshold spectral sensitivity on an achromatic background, heterochromatic flicker photometry, and colorimetric purity discrimination. With a task of heterochromatic flicker photometry, the anomalous trichromatic observers showed spectral sensitivity of the corresponding dichromat. The increment threshold spectral sensitivity and colorimetric purity discrimination data were analyzed using the concept of standard cone photopigment spectral sensitivities for normal and defective vision, and a model that postulates one cone-additive and two cone-antagonistic systems. The model incorporated a shift of the peak spectral sensitivity of the long-wavelength-sensitive (LWS) pigment (for protan observers) or of the middle-wavelength-sensitive (MWS) pigment (for deutan observers). Two dichromats and two anomalous trichromats did not show clear evidence of LWS vs MWS cone antagonism. Five anomalous trichromats showed such cone antagonism. Molecular genetic analysis of the opsin genes is presented for eight of the observers.

DOI: 10.1016/0042-6989(95)00215-4

Extracted Key Phrases

15 Figures and Tables


Citations per Year

124 Citations

Semantic Scholar estimates that this publication has 124 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Miyahara1996IncrementTA, title={Increment threshold and purity discrimination spectral sensitivities of X-chromosome-linked color-defective observers}, author={Eriko Miyahara and Joel Pokorny and Vivianne C. Smith}, journal={Vision Research}, year={1996}, volume={36}, pages={1597-1613} }