Principal Investigator Emilio Bizzi
Investigations from several laboratories have shown that motor learning involves processes parallel to those involved in learning episodic information. For instance, learning a specific motor task is impaired if a second motor task is attempted shortly thereafter (retrograde interference) but not if the second motor task is learned four hours after the first task (motor memory consolidation). While the neuroanatomical basis for episodic memory has been well-delineated, the regions that support motor learning are less clearly defined.
Single cell studies in nonhuman primates adapting to a novel dynamical environment have been performed in our laboratory. These experiments have shown substantial plastic changes in motor and premotor cortex as the monkeys learn a reaching task. While such studies provide a great deal of knowledge concerning the areas involved in motor learning and the neural mechanisms of adaptation, they in general fail to prove the causal relationship of these areas with motor learning. An active role, for instance of M1, would instead be shown by studies using reversible focal modulation. In that respect, the technique of transcranial magnetic stimulation (TMS), allowing for the temporary and non-invasive stimulation of specific regions of the cortex, offers a unique opportunity to address these issues in humans.