Date of Award

Winter 1993

Project Type

Dissertation

Program or Major

Psychology

Degree Name

Doctor of Philosophy

First Advisor

Kenneth Fuld

Abstract

The Jameson and Hurvich opponent colors model of hue and saturation was tested for spectral and non-spectral lights. Four observers scaled, using standard color naming techniques, the hue and saturation of both spectral and non-spectral lights. These lights consisted of 11 wavelengths from 440 to 640nm in steps of 20nm and consisted of 5 purities, 1.0, 0.80, 0.60, 0.40 and 0.20. Admixtures of monochromatic light and a xenon-white desaturant yielded the different colorimetric purities. For each observer, chromatic response functions were measured by the method of hue cancellation for each purity, and an achromatic response function was measured by the method of heterochromatic flicker photometry for spectral lights. Chromatic response functions measured for a particular purity and the achromatic response function were used to predict hue and saturation for that purity. Hue varied with purity, the Abney effect, consistent with what would be expected due to additivity and opponent cancellation if the xenon-white desaturant were yellowish. The model made approximate predictions of hue for each purity, but failed to predict precisely the Abney effect. Previous results of a minimum forming on the saturation function at 480nm with decreasing purity were confirmed. This minimum was possibly due to opponent cancellation between the yellowish xenon-white and the predominately blue appearing 480nm light. An additional experiment demonstrated that the xenon-white appeared yellowish. The model made relatively poor predictions of saturation, tending to overestimate short-wave lights and underestimate long-wave lights. The possibility of the rods contributing to saturation was discussed. An additional experiment found that stimulus parameters that favor rod contribution weaken the model's predictions of saturation, while stimulus parameters that do not favor rod contribution improve the model's predictions of saturation.

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