Plasticity of cortical function related to voluntary movement motor learning and compensation following brain dysfunction

Processes of motor learning and of compensation after localized brain dysfunction were studied in the monkey tasked with conditioned (visually-initiated, reaction-time) hand movements. Field potentials in various cortical areas of the cerebral hemisphere were recorded successively for many months with electrodes implanted on the surface and in the depth of the cortex. The potentials associated with the conditioned movement were found to change during processes of learning the movement and during courses of degradation as well as recovery after the brain dysfunction.