Cortical preparatory activity indexes learned motor memories

Article

关键词: BRAIN-COMPUTER INTERFACE;    DYNAMICS;    CORTEX;    ADAPTATION;    MOVEMENT;    REPRESENTATION;    COMPUTATION;    SYSTEMS;   

DOI  :  10.1038/s41586-021-04329-x

来源: SCIE

【 摘 要 】

The brain's remarkable ability to learn and execute various motor behaviours harnesses the capacity of neural populations to generate a variety of activity patterns. Here we explore systematic changes in preparatory activity in motor cortex that accompany motor learning. We trained rhesus monkeys to learn an arm-reaching task(1) in a curl force field that elicited new muscle forces for some, but not all, movement directions(2,3). We found that in a neural subspace predictive of hand forces, changes in preparatory activity tracked the learned behavioural modifications and reassociated(4 )existing activity patterns with updated movements. Along a neural population dimension orthogonal to the force-predictive subspace, we discovered that preparatory activity shifted uniformly for all movement directions, including those unaltered by learning. During a washout period when the curl field was removed, preparatory activity gradually reverted in the force-predictive subspace, but the uniform shift persisted. These persistent preparatory activity patterns may retain a motor memory of the learned field(5,6) and support accelerated relearning of the same curl field. When a set of distinct curl fields was learned in sequence, we observed a corresponding set of field-specific uniform shifts which separated the associated motor memories in the neural state space(7-9). The precise geometry of these uniform shifts in preparatory activity could serve to index motor memories, facilitating the acquisition, retention and retrieval of a broad motor repertoire.

【 授权许可】

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