小柯机器人

皮层准备活动是学习运动记忆的指标
2022-01-30 23:38

美国斯坦福大学Krishna V. Shenoy、Xulu Sun等研究人员合作发现,皮层准备活动是学习运动记忆的指标。相关论文于2022年1月26日在线发表在《自然》杂志上。

研究人员探讨了伴随运动学习的运动皮层中准备活动的系统变化。研究人员训练了恒河猴在一个卷曲力场中学习手臂伸展的任务,该力场对一些,但不是所有的运动方向引起新的肌肉力量。研究人员发现,在预测手部力量的神经子空间中,准备活动的变化跟踪了学习的行为修改,并将现有的活动模式与更新的运动重新联系起来。沿着与预测力的子空间正交的神经群体维度,研究人员发现准备活动对所有运动方向都有统一的转变,包括那些未被学习改变的运动方向。在去除卷曲场的清除期,准备活动在力预测子空间中逐渐恢复,但均匀的转移仍然存在。这些持续的准备活动模式可能保留了对所学领域的运动记忆,并支持加速对同一卷曲领域的再学习。
 
当一组不同的卷曲领域被依次学习时,研究人员观察到一组相应的特定领域的均匀移动,它将神经状态空间中的相关运动记忆分开。准备活动中这些均匀移动的精确几何形状可以作为运动记忆的索引,从而促进广泛运动行为的获得、保留和检索。
 
据介绍,大脑学习和执行各种运动行为的非凡能力利用了神经群体产生各种活动模式的能力。
 
附:英文原文
 
Title: Cortical preparatory activity indexes learned motor memories

Author: Sun, Xulu, OShea, Daniel J., Golub, Matthew D., Trautmann, Eric M., Vyas, Saurabh, Ryu, Stephen I., Shenoy, Krishna V.

Issue&Volume: 2022-01-26

Abstract: 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 task1 in a curl force field that elicited new muscle forces for some, but not all, movement directions2,3. We found that in a neural subspace predictive of hand forces, changes in preparatory activity tracked the learned behavioural modifications and reassociated4 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 field5,6 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 space7,8,9. 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.

DOI: 10.1038/s41586-021-04329-x

Source: https://www.nature.com/articles/s41586-021-04329-x

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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