Preparatory activity in motor cortex reflects learning of local visuomotor skills
Nat Neurosci. 2003-07-20; 6(8): 882-890
DOI: 10.1038/nn1097
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Paz R(1), Boraud T, Natan C, Bergman H, Vaadia E.
Author information:
(1)Department of Physiology, Hadassah Medical School, The Hebrew University, Box
12272, Jerusalem 91120, Israel.
In humans, learning to produce correct visually guided movements to adapt to new
sensorimotor conditions requires the formation of an internal model that
represents the new transformation between visual input and the required motor
command. When the new environment requires adaptation to directional errors,
learning generalizes poorly to untrained locations and directions, indicating
that such learning is local. Here we replicated these behavioral findings in
rhesus monkeys using a visuomotor rotation task and simultaneously recorded
neuronal activity. Specific changes in activity were observed only in a
subpopulation of cells in the motor cortex with directional properties
corresponding to the locally learned rotation. These changes adhered to the
dynamics of behavior during learning and persisted between learning and
relearning of the same rotation. These findings suggest a neural mechanism for
the locality of newly acquired sensorimotor tasks and provide
electrophysiological evidence for their retention in working memory.