THE GOLDFISH - A COLOR-CONSTANT ANIMAL

A series of either thirteen or fifteen coloured test fields with hues from blue through grey to yellow were presented on a black background. Goldfish were trained on a bluish-grey test field by food reward. In the training situation, the setup with the coloured papers was illumin ated with white light. In the test situation, the colour of the illumi nation was changed to blue or yellow. In both test illuminations the g oldfish preferred the training field in the same way as under white il lumination despite the fact that this test field stimulated the cone t ypes very differently from the training situation. As test fields were present that excited the cones in exactly the same way as under white light, but were not chosen, colour constancy can be concluded. By mea ns of colour metrics, it was possible to quantify direction and streng th of colour constancy.