Effect of microgravity on the implementation of conditioned reflex skills of rhesus monkeys.

The success of two monkeys in performing an eye-head-hand coordination task was investigated during the Bion 11 flight. In comparison to the ground controls, it took the flight monkeys more time to reach the light stimuli located at 40 degrees to the left or right from the center of the panel in front of them. During flight days (FD) 5-6, the precision of hand movements deteriorated, and during FD 7-14, it improved, although the performance time increased.