Do common mechanisms of adaptation mediate color discrimination and appearance? Uniform backgrounds

Hillis, J.M. and Brainard, D.H. (2005) Do common mechanisms of adaptation mediate color discrimination and appearance? Uniform backgrounds. Journal of the Optical Society of America A: Optics Image Science and Vision(22), pp. 2090-2104. (doi: 10.1364/JOSAA.22.002090)

Abstract

Color vision is useful for detecting surface boundaries and identifying objects. Are the signals used to perform these two functions processed by common mechanisms, or has the visual system optimized its processing separately for each task? We measured the effect of mean chromaticity and luminance on color discriminability and on color appearance under well-matched stimulus conditions. In the discrimination experiments, a pedestal spot was presented in one interval and a pedestal + test in a second. Observers indicated which interval contained the test. In the appearance experiments, observers matched the appearance of test spots across a change in background. We analyzed the data using a variant of Fechner's proposal, that the rate of apparent stimulus change is proportional to visual sensitivity. We found that saturating visual response functions together with a model of adaptation that included multiplicative gain control and a subtractive term accounted for data from both tasks. This result suggests that effects of the contexts we studied on color appearance and discriminability are controlled by the same underlying mechanism.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hillis, Dr James
• Authors: Hillis, J.M., and Brainard, D.H.
• College/School: College of Science and Engineering > School of Psychology; College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Journal of the Optical Society of America A: Optics Image Science and Vision
• Publisher: Optical Society of America
• ISSN: 1084-7529
• ISSN (Online): 1520-8532