Perceptual considerations in the use of colored photographic and video stimuli to study nonhuman primate behavior

The use of photographs, slides, computerized images, and video to study behavior is increasingly being employed in nonhuman primates. However, since these mediums have been designed to simulate natural coloration for normal trichromatic human vision, they can fail to reproduce color in meaningful and accurate ways for viewers with different visual systems. Given the range of color perception that exists both across and within different species, it is necessary to consider this variation in order to discern the suitability of these mediums for experimental use. Because of the high degree of visual similarity among humans, Old World monkeys, and apes, the use of photographic and video stimuli should be acceptable in terms of replicating naturalistic coloration and making noticeable color manipulations. However, among New World primates and prosimians, there exists a considerable degree of variation in color perceptual abilities depending on the species, sex, and allelic combination of the animals involved. Therefore, the use of these mediums to study behavior is problematic for these species, and should be done with caution.