(1) The colour perception process

Abstract

Though colour vision is generally accepted to operate with three types of receptor comparatively little is understood of the way the responses of these receptors are transmitted to and interpreted by the brain. Prof Wright opened the meeting by describing current theories of colour perception and particularly possible methods of coding receptor signals for transmission to the brain. Jennifer Birch remained on the much firmer ground of colour defects. She described the types of colour deficiency that occur and the tests that are used to determine types and degrees of deficiency. D. A. Palmer then discussed the relationship between colour vision and illuminance. At low illuminances colour vision may sometimes be sacrificed in favour of mere visibility by pooling of the cone responses.