Manual and hemispheric specialization in the manipulation of a joystick by baboons (Papio papio).

Manual performance asymmetries were examined in 8 baboons (Papio papio). Using a joystick, monkeys had to track and hit with a cursor a randomly moving target on a monitor. The left or right hand was tested first, depending on group assignment, followed by a transfer to the other hand. A transfer effect is reported for the total number of trials to criterion and total number of successful trials. No effect was found for response time. However, for both test and transfer, the group initially tested with the left hand exhibited more controlled movements as demonstrated by shorter cursor's paths. Overall, it appears that the spatial components of the task are more sensitive to laterality effects than response times or learning scores.