CONSOLIDATION IN HUMAN MOTOR MEMORY

LEARNING a motor skill sets in motion neural processes that continue t o evolve after practice has ended, a phenomenon known as consolidation (1-4). Here we present psychophysical evidence for this, and show that consolidation of a motor skill was disrupted when a second motor task was learned immediately after the first. There was no disruption if f our hours elapsed between learning the two motor skills, with consolid ation occuring gradually over this period. Previous studies in humans and other primates have found this time-dependent disruption of consol idation only in explicit memory tasks(5-12), which rely on brain struc tures in the medial temporal lobe(9,13,14). Our results indicate that motor memories, which do not depend on the medial temporal lobe(8,15), can be transformed by a similar process of consolidation. By extendin g the phenomenon of consolidation to motor memory, our results indicat e that distinct neural systems share similar characteristics when enco ding and storing new information.