International Journal of Comparative Psychology

Thirteen naïve capuchin monkeys ( Cebus [Sapajus] apella ) were manually tested with the Transfer Index procedure, a species-fair paradigm for assessing the capacity to learn and to transfer learning. The animals were then trained to manipulate a joystick to control a cursor and to respond to stimuli on a computer screen. After the animals had mastered the remote cause-effect relations required by the computerized test system, they were returned to manual Transfer Index testing to determine whether the joystick-training intervention had affected the monkeys’ capacity for efficient and relational learning.  Transfer Index scores and overall accuracy was higher following the joystick intervention, but these differences were not statistically significant. Two-choice discrimination learning and reversal appeared to be associative in nature, and there was no evidence that joystick training made the monkeys more rule-like or relational in their learning. Despite the absence of significant differences, the patterns of results encourage further study of the ways that changes in the cognitive competencies of nonhuman animals might be catalyzed by significant learning experiences.