Abstract # 2231 Poster # 144:

Scheduled for Friday, June 22, 2007 05:00 PM-07:00 PM: Session 14 (South Main Hall) Poster Presentation

Rhesus Macaques (Macaca mulatta) Process Gaze When Making Choices: Evidence of Seeing and Knowing

C. A. Major1 and M. A. Novak1,2
1University of Massachusetts Amherst, Tobin Hall, Neuroscience and Behavior Graduate Program, Amherst, MA 01003, USA, 2Psychology Department, University of Massachusetts Amherst, Tobin Hall, Amherst, MA, 01003, USA
     Attribution of knowledge refers to equating a shared visual perspective with shared information, a characteristic of human behavior. However, there is considerable debate as to whether nonhuman primates understand the significance of gaze and will select a treat from an experimenter that looks at them as opposed to one that does not. In previous studies, chimpanzees could not differentiate between looking and nonlooking experimenters. However, treats were held in the hands, a considerable distance from the face. We asked whether rhesus monkeys could discriminate lookers from nonlookers. We eliminated the problem of focusing on the hands by holding treats in close proximity to the experimenter's eyes. During familiarization, 5 monkeys were given 10 standard trials per day in which two experimenters looked in the direction of the monkey, one holding a treat and the other holding chow. During testing, 4 standard trials were replaced with probes in which both experimenters held a treat. One experimenter either turned his head away from the monkey or covered his eyes. Position, experimenter, probe trial, and reward type (on standard trials) were block randomized. Data were analyzed using binomial probabilities with a=0.05. Two of the monkeys requested food from the experimenter looking at them significantly more than would be expected by chance, but performance differed depending on probe trial. These data suggest that some rhesus macaques have the ability to understand the connection between seeing and knowing.