Operant responding by bonnet macaques for color videotape recordings of social stimuli

Abstract

Socially reared juvenile bonnet macaques responded at high sustained levels in an operant task for presentation of color videotaped television images of social stimuli. Absolute levels of response depended upon the nature of the stimulus. In two experiments, subjects responded at 60.8% and 74.6% of the 1-h experimental sessions for presentation of a color videotape of a conspecific adult female moving freely in an enclosed stimulus chamber. In a later experiment, subjects maintained high levels of response during 15-min sessions for presentations of the conspecific image, but responded with significantly shorter duration responses for similar presentation of a videotape of an adult female of another macaque species, a still picture of a conspecific adult female, and a videotape of the empty stimulus chamber. With longer, 1-h, stimulus presentation, the three social stimuli sustained high levels of response while responses for presentation of the empty stimulus chamber waned significantly over the experimental session. The sustained high levels of response obtained over several hours of stimulus presentation suggest the value of color videotape stimuli in the experimental study of social perception in nonhuman primates.