The multiple components of motor memory

运动记忆的多个组成部分

基本信息

批准号：
9888436
负责人：
REZA SHADMEHR
金额：
$ 35.92万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-15 至 2022-02-28
项目状态：
已结题

项目摘要

When we practice a motor task, we can do it better the next time we revisit it. How is this accomplished? The basic assumption in neuroscience has been that during practice, we learn an association between the stimulus and the appropriate motor commands. However, it has been difficult to reconcile this view with two basic behavioral results: (1) when learning is followed by a long period of washout (removal of the perturbation), the motor memory appears protected from erasure (termed “savings”). How is it that learning followed by washout does not erase the association between stimulus and motor commands? (2) When washout is following by learning of the opposite perturbation, subjects exhibit meta-learning, i.e., performance is better than naïve in a perturbation opposite to the one that they had initially learned. How could learning to associate a stimulus to one direction of motor commands followed by washout help in learning in the opposite direction? Here, we approach these problems from a new perspective: the neural architecture that supports motor learning in the cerebellum. We propose that in the cerebellum, micro-clusters of Purkinje cells (P-cells) are organized based on their preference for error. This preference is expressed in their complex-spike tuning (encoding of error), which in turn provides a coordinate system in which simple spikes can be understood. The P-cell’s error preference makes it so that when error changes, anatomically distinct P-cell micro-clusters are recruited. As a result, when a perturbation is followed by washout, error changes direction and engages new groups of P-cells, producing a new memory without erasing the old. The same hypothesized anatomy suggests that meta-learning arises not because of similarity of the motor commands, but because of the similarity of errors. Using this hypothesis we show that when simple spikes of P-cells are organized into micro-clusters, an exquisite encoding of motion emerges. We propose to test a host of predictions regarding both the neurophysiological correlates of error-dependent learning in the cerebellum, and its behavioral correlates of savings and meta-learning in healthy people. Finally, we use the theory to better understand a latent form of motor learning in people with damage to their cerebellum. From a clinical perspective, our work aims to understand how the brain stores motor memories, and how it up-regulates learning from error, questions that are relevant to motor rehabilitation following neuro- trauma and disease. Our theory provides a recipe to modulate error-sensitivity, which should produce faster motor learning, potentially affecting the duration of rehabilitation.

当我们练习电动机任务时，我们下次重新审视它时可以做得更好。这是如何完成的？这神经科学的基本假设是，在实践中，我们学习刺激之间的关联和适当的电动机命令。但是，很难将这种观点与两个基本观点调和行为结果：（1）在学习之后进行长时间的冲洗（去除扰动）时，电动机存储器似乎保护不受擦除（称为“储蓄”）。如何学习然后冲洗不删除刺激和电机命令之间的关联吗？（2）擦洗通过了解相反的扰动，受试者暴露了元学习，即表现更好比他们最初学到的那个相反的扰动中的天真。如何学习将刺激与电机命令的一个方向相关方向？在这里，我们从新的角度解决了这些问题：支持的神经体系结构小脑的运动学习。我们提出，在小脑中，Purkinje细胞的微簇（P细胞）根据他们对错误的偏爱而组织。这种偏好在其复杂的尖峰调整中表达（错误的编码），这又提供了一个坐标系，可以理解简单的尖峰。这 p-cell的错误偏好使得这是如此，因此当错误变化时，解剖学上不同的p细胞微群体是招募。结果，当扰动随后进行冲洗时，错误会改变方向并与新的联系一组P细胞，产生新的记忆，而无需擦除旧记录。相同的假设解剖结构表明元学习不是因为电机命令的相似性，而是因为错误。使用此假设，我们表明，当简单的P细胞尖峰被组织到微群体中时出现了精美的运动编码。我们建议测试有关两者的大量预测小脑中错误依赖性学习的神经生理学相关性，其行为相关性在健康的人中储蓄和元学习。最后，我们利用理论更好地理解对小脑受损的人的运动学习。从临床角度来看，我们的工作旨在了解大脑如何存储运动记忆，并且它如何上调从错误中学习，与Neuro-之后与运动康复相关的问题创伤和疾病。我们的理论提供了调节误差敏感性的配方，这应该更快地产生运动学习，可能影响康复的持续时间。