Chromatic adaptation in the honeybee: Successive color contrast and color constancy

Summary

Successive color contrast and color constancy were investigated with a behavioral training technique using pigment colors. In both experiments, single, freely flying bees were trained to land on one out of 9 differently colored test fields presented on a grey background.

• 1. To investigate successive color contrast bees were exposed to a yellow or a blue adaptation color for several minutes and their choice behavior was tested immediately thereafter. Test fields less blue than the original training test field were chosen after adaptation to yellow, test fields of stronger blue after adaptation to blue (Fig. 2). This indicated that the ‘bee-subjective’ blue-green test fields must have appeared more blue after adaptation to yellow, and less blue after adaptation to blue. The effect lasted for about 2–3 min after adaptation durations of 1 and 2 min, and even longer after adaptation of 5 min measured for the yellow adaptation color (Fig. 3).

• 2. To investigate color constancy bees were trained under a ‘white’ illumination, and tested under various yellow and blue illuminations. The choice behavior revealed (Fig. 4) that under almost all conditions, the training test field was clearly preferred. This indicated that the test fields appeared in almost unchanged hues, despite the fact that the light reflected by a given test field stimulated the three receptor types in very different ratios (Fig. 5). The mean choice behavior did not change significantly during the course of a test period under colored illumination (Fig. 6). In the following test period under ‘white’ illumination, aftereffects of chromatic adaptation were observed (Fig. 7).