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Two experiments were conducted to examine the effectiveness of presenting brief video of conspecifics to socially housed bonnet macaques as a reward for performing a joystick task. Using a joystick, subjects tracked a moving target with the cursor on a computer monitor. In Exp. 1, subjects completed significantly more joystick trials for food reward than for video reward or no reward. Subjects also preferred viewing video of another group (Other Group Video) to receiving no reward or to viewing video of their own group (Own Group Video). In Exp. 2, subjects were given two reward conditions, video of a familiar social group or video of a new social group. Two monkeys contributed the vast majority of trials, and both responded more frequently when the reward was video of the new social group. Results of these two experiments suggest that viewing video of conspecifics may serve as an effective reward for at least some socially housed primates and suggests that novelty of the individuals depicted in the video is an important factor contributing to the reward value of video.

A number of studies have now indicated that monkeys of several species will perform hundreds of food-rewarded joystick tasks on a daily basis. Our goal in this study was to identify the level of joystick task performance that could be maintained by 10 sec. of live, color video of a conspecific social group contingent upon the completion of a joystick task. The subjects were five individually housed bonnet macaques that were highly experienced on joystick tasks. Performance with social-video reward was compared to that maintained by a 190-mg banana-flavored pellet reward and to a nonreward condition. Comparable levels of task activity were maintained by both video and pellet reward, whereas task activity nearly ceased in the absence of reward. Four of the five monkeys increased their levels of task activity between the first and second weeks of social-video reward.