Effects of Memory Colour on Colour Constancy for Unknown Coloured Objects

Abstract

The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

Quantitative studies of animal colour constancy: using the chicken as model

“…In experiment 3, chickens did not remain colour-constant in as large colour shifts of the illumination as in experiment 2. Learning of the unrewarded colours in the discrimination task seems to facilitate correct choices in changed illuminations and thus colour constancy, a phenomenon that is also known in humans [44].…”

How Reliable is Perception?

“…Learning that an especially delicious berry has a particular color as observed at noon, would be all the more useful if the knowledge could be generalized to seeing the berry at twilight. Color constancy mechanisms-partly evolved, partly learned (Delahunt & Brainard, 2004;Granzier & Gegenfurtner, 2012)-are a solution to this problem. But that we perceive something as 'red' across a range of contexts does not mean that there is some invariantly "red" thing out there.…”

Cross-cultural variation of memory colors of familiar objects

“…They have been investigated as a possible mechanism to improve the color constancy of other objects, as they provide cues to the visual system to help estimate the illumination. Although, Granzier and Gegenfurtner [14] reported a small improvement, neither Ling [15], nor Kanematsu and Brainard [16] identified such effect. Ling [17], as well as others [18][19][20] did however report an influence of the memory color on the perceived color of the familiar object itself, consistent with Hering's statement that "All objects that are already known to us from experience, or that we regard as familiar by their color, we see through the spectacles of memory color."…”