Cat color vision: the effect of stimulus size

Science  17 Mar 1978:
Vol. 199, Issue 4334, pp. 1221-1222
DOI: 10.1126/science.628838


Adult cats were trained to discriminate blue from green and gray. Although the cats could discriminate the intensity of stimuli whose areas ranged from 33 to 0.36 square centimeters they could not discriminate color when the stimulus was 0.36 square centimeter (less than 20 degrees visual angle). This influence of stimulus size may account for both positive and negative results of previous studies.