Central neural mechanisms of prehension.

The digital dexterity seen in man and macaque monkeys but not present in other primates, such as the squirrel monkey, occurs without anatomical specialization of the hand. The central nervous system apparatus essential to such dexterity resides in the motor cortex and its outflow to lower centres. Areas other than the motor cortex are involved in the initiation and execution of complex sequential movements, including those of the fingers and hand. These include the supplementary motor and premotor areas of the cerebral cortex and the lateral parts of the cortex and the deep nuclei of the cerebellum.