Motor Cortical Function During Motor Learning with a Brain-Machine Interface

 描述（由申请人提供）：脑机接口（BMI）承诺通过使用瘫痪个体自己的神经活动来控制计算机光标、机器人手臂甚至他们自己的肢体的运动，来恢复瘫痪个体的自主运动。一类“仿生”BMI研究渴望让患者通过想象自然的肢体运动来控制BMI。然而，当实验猴子从正常运动过渡到控制BMI时，控制神经元以指示运动学习的方式改变其放电模式。当猴子达到最佳表现时，这些变化会发生在几个阶段，这表明仍然需要学习神经活动和所需运动之间的新映射。我的建议的目标是通过更好地理解在正常运动任务和BMI范例的运动学习过程中皮层神经元的活动如何以及为什么会发生变化来改善BMI控制。我将研究两个功能不同的运动皮层区域，初级运动皮层（M1）和背侧运动前皮层（PMD），如何协同工作，以协调运动。更好地了解这些区域在正常运动中的作用将使我们能够设计更多的仿生BMI。 由于适应BMI使用和传统的运动学习之间的明显相似性，我建议首先研究运动皮层神经元的运动相关活动在两个常见的运动学习任务中的变化。已知M1和PMd在到达中具有不同的作用，其中M1活动与肢体动力学和肌肉激活密切相关，而PMd编码运动目标和规划。这些区域中神经元的不同功能行为表明它们在BMI控制方面的效用可能不同。我首先建议研究如何M1和PMd改变他们的dischage猴子达到运动中存在的两个扰动：一个速度依赖的力场（“旋度场”）和静态visuality旋转。我将研究如何使用神经空间调谐分析方法，以及通过推断神经元之间的功能连接的变化，两个神经种群的变化，以调解适应。 在第二个目标中，我将扩展我的实验，包括BMI任务，以更好地理解BMI使用期间观察到的皮质变化。猴子将使用M1或PMd神经元在多个会话中控制光标。随着猴子的适应，我将描述BMI技能获得背后的空间调谐或功能连接的变化。此外，我将测试M1对照品和PMd对照品之间存在的差异（如果有的话）。这两个目标的结果将有助于理解运动学习的神经基础，M1和PMd如何协同工作以协调运动，以及M1和PMd如何用于创建更仿生的BMI。

 DESCRIPTION (provided by applicant): Brain-machine interfaces (BMIs) promise to restore voluntary movement to paralyzed individuals by using their own neural activity to control movement of computer cursors, robotic arms, or even their own limbs. A class of "biomimetic" BMI research aspires to allow patients to control the BMI by imagining natural limb movements. However, as experimental monkeys transition from normal movements to controlling a BMI, the control neurons alter their discharge patterns in a manner indicative of motor learning. These changes, which occur over several sessions as the monkeys achieve peak performance, suggest there is nonetheless, a need to learn a new mapping between neural activity and the desired movements. The goal of my proposal is to improve BMI control through a better understanding of how and why the activity of cortical neurons changes during motor learning during both normal motor tasks and a BMI paradigm. I will investigate how two functionally distinct motor cortical areas, primary motor cortex (M1) and dorsal premotor cortex (PMd), work together to coordinate movements. A better understanding of the role of these areas in normal movements will allow us to design more biomimetic BMIs. Due to the apparent similarity between adapting to BMI use and traditional motor learning, I propose first to study how movement-related activity of motor cortical neurons changes during two common motor learning tasks. M1 and PMd are known to have different roles in reaching, with M1 activity that is closely related to limb dynamics and muscle activation and PMd encoding movement goals and planning. The different functional behavior of neurons in these areas suggests that they may differ in their utility for BMI control. I first propose to study how M1 and PMd alter their dischage as monkeys make reaching movements in the presence of two perturbations: a velocity-dependent force field ("curl field") and a static visuomotor rotation. I will study how the two neural populations change to mediate adaptation using neural spatial tuning analysis methods as well as by inferring changes in functional connectivity between neurons. In the second aim, I will extend my experiments to include a BMI task to better understand the cortical changes observed during BMI use. Monkeys will use either M1 or PMd neurons to control a cursor over multiple sessions. As the monkeys adapt, I will characterize the changes in spatial tuning or functional connectivity underlying BMI skill acquisition. Additionally, I will test for what differences, if any, exist between M1 control and PMd control. The results of these two aims will help to understand the neural basis of motor learning, how M1 and PMd work together to coordinate movements, and how M1 and PMd might be used to create a more biomimetic BMI.