Abstract # 1946 Poster # 89:

Scheduled for Thursday, August 17, 2006 07:00 PM-09:00 PM: Session 8 (Regency West 1/3 ) Poster Presentation

Young rhesus monkeys (MACACA MULATTA) learn about cognitive tasks before they can perform them

M. L. Snyder1,2, C. I. Kenney1, M. K. Unkefer1,2, A. M. Ruggiero1, S. J. Suomi1 and M. S. Novak1
1NIH-NICHD-LCE NIH Animal Center, P.O. Box 529, Poolesville, MD 20837, USA, 2Northern Virginia Community College, Loudoun Campus
     In 1930, Tolman and Honzik published an essay on latent learning in which they demonstrated that rats were learning about maze running in the absence of reinforcement. In this study we were interested in determining the ideal start age for testing infant rhesus monkeys on discrimination learning tasks using a Wisconsin General Testing Apparatus (WGTA). We started infants (N=9) on the task at 2 (n=3), 3 (n=2), 3.5 (n=2) and 4 (n=2) months of age. All groups went through an initial adaptation phase to acclimate the animals to the testing environment, followed by a simple pattern discrimination and finally a reversal stage in which they learn the opposite pattern. Although not significant, the youngest group of infants took longer to complete the adaptation phase of testing (M=78 days, SD=12.5 versus M=40.3 days SD=23.6). This was true even in animals tested more often. Surprisingly, however, once adaptation was finished, the youngest group reached criterion on the first black/white task sooner than any of the older groups (M=6.3 days, SD=3.1 versus M=37 days, SD=31.2; ns). The results suggest that while starting infants at older ages cut down on the initial adaptation phase of the experiment, starting them younger they reached criterion faster once the adaptation phase was finished. It is possible that the younger animals were learning about the task even in the absence of the ability or willingness to perform the task. This research was supported by the intramural research program of the NICHD at the NIH.