SIMULTANEOUS COLOR CONTRAST IN GOLDFISH - A QUANTITATIVE STUDY

A set of 9-15 colored test fields was presented to goldfish. In Experi ment 1, test field hues ranged from green through yellow to red; in Ex periment 2, the hues varied from blue through gray to yellow. In the t raining conditions, the test fields were presented with a gray or blac k surround. The fish learned to choose one intermediate test field hue by rewarding them with food. In the test conditions, the color of the surround was changed from gray to green, or red (Experiment 1), and f rom black to blue, or yellow (Experiment 2). The choice behavior of th e goldfish changed substantially: one of the test fields other than th e training test field was preferred. Direction and strength of simulta neous color contrast was quantified in goldfish color space. The effec t of spatial stimulus configuration was investigated by changing test held size and using narrow annular surrounds. With test held radii ran ging between 2 and 7.5 mm simultaneous color contrast was optimal when ever the ratio between surround width and test held radius had a value of about 1:1. (C) 1997 Elsevier Science Ltd.