The multiple components of motor memory

运动记忆的多个组成部分

基本信息

批准号：
8683267
负责人：
REZA SHADMEHR
金额：
$ 36.99万
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 2017-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Our ability to adapt to systematic perturbations makes it possible to maintain a lifetime of calibrated movements. Our focus here is on the neural basis of this motor memory. The current view is that adaptation depends critically on the cerebellum. However, over the last two years we, and others, have made a series of observations that challenge this view of adaptation. Here we suggest a different view of the problem of motor adaptation based on the core hypothesis that the cerebellum is embedded in a larger network that includes motor cortical areas, and that more than one mechanism is involved in forming a motor memory. Specifically, we suggest that motor memory is a result of interaction of distinct components: one component associates motor commands with sensory consequences, resulting in a forward model; one component searches the motor space for output that can produce a rewarding outcome, resulting in exploration; a third component relies on repetition to associate the sensory feedback with the motor commands, resulting in a feedback- dependent controller. In Aim 1, we will test that idea that the function of M1 during adaptation is to encode a component of motor memory that depends on reinforced repetition of motor commands. In Aim 2, we will test the hypothesis that damage to the cerebellum affects only one component of motor memory, the ability to form memories that depend on sensory prediction errors (forward models), but spares the ability to learn from repetition of motor commands. Our projects are clinically important because if we are right in that there are multiple neural pathways to formation of motor memory, then damage to one component may benefit from rehabilitation procedures that focus on remaining healthy neural structures. Our projects are important from a basic science standpoint because: (1) our experiments can connect the cerebellar-centric field of adaptation which has focused on error-dependent learning, with cerebral cortex-centric field of motor learning which has focused on repetition-dependent processes; (2) our experiments have the power to explain what is being 'prepared' by the brain during the preparatory period before movement onset; and finally (3) our experiments have the potential to actually test computational ideas that are very much in fashion in the field of optima control, and ask whether they have any relevance to the neural basis of motor control.

描述（由申请人提供）：我们适应系统的扰动的能力使得可以保持一生的校准运动。我们这里的重点是这种运动记忆的神经基础。当前的观点是，适应取决于小脑。但是，在过去的两年中，我们和其他人进行了一系列观察，挑战了这种适应观点。在这里，我们建议基于核心假设，即小脑被嵌入在包括运动皮质区域的较大网络中，并且有多种机制参与形成运动记忆的较大网络。具体而言，我们建议电动机存储器是不同组件相互作用的结果：一个组件将电动机命令与感官后果相关联，从而导致了正向模型。一个组件搜索电动机空间以产生有意义的结果，从而导致探索。第三个组件依靠重复来将感觉反馈与电动机命令相关联，从而导致反馈依赖的控制器。在AIM 1中，我们将测试该想法，即M1在适应过程中的功能是编码运动记忆的组件，该组件取决于马达命令的加强重复。在AIM 2中，我们将检验以下假设：小脑损害仅影响电动机记忆的一个组成部分，即形成依赖感觉预测错误（正向模型）的记忆的能力，但避免了从重复运动命令中学习的能力。我们的项目在临床上很重要，因为如果我们是正确的，因为有多种神经途径来形成运动记忆，那么对一个组件的损害可能会受益于康复程序，而康复程序则侧重于保持健康的神经结构。从基本科学的角度来看，我们的项目很重要，因为：（1）我们的实验可以连接以小脑为中心的适应性领域，该领域的重点是依赖错误的学习，并以大脑皮层为中心的运动学习领域的运动领域，该领域的重点是重复依赖性过程；（2）我们的实验有能力解释在运动开始前的准备期间，大脑正在“准备”什么；最后（3）我们的实验有可能实际测试在Optima控制领域非常流行的计算思想，并询问它们是否与运动控制的神经基础有任何相关性。