Cortical mechanisms underlying predictive motor planning

眼睛和手臂的协调运动是大多数日常活动中使用的。这样的运动需要一系列的感觉运动转换，利用视觉、本体感觉以及眼睛和手臂位置信号来计划和执行通常观察到的协调反应。人类能够轻而易举地产生和控制这种反应，掩盖了规划过程中固有的潜在复杂性。这一点在脑损伤患者中变得明显，他们通常难以产生协调的眼睛和手的运动，因此导致更多地依赖照顾者和家庭成员的支持。在我的实验室进行的这项研究旨在更好地了解与眼手协调相关的感觉运动转换背后的神经机制。我的研究团队使用行为操作和经颅磁刺激(TMS)诱导的皮质处理扰动相结合的方法对此进行了研究。眼手协调的一个鲜为人知的组成部分是基于运动输出的预期感觉结果来指导运动的预测性信号。特别是，目前还不清楚这些信号如何以及何时对运动规划起作用，以及大脑中的哪些结构负责这样做。因此，当前提案的目标是1)使用行为操纵的组合来直接探索预测性计划过程的性质和时间；以及2)使用TMS来直接评估几种不同的大脑结构在这一过程中的贡献。综上所述，本申请中提出的实验将使我们能够更好地理解预测运动规划的时间动力学，以及不同的大脑区域如何对此规划做出贡献。这些信息可以用来更好地为当前的肢体运动控制理论提供信息。

Coordinated movements of the eyes and arm are used for most everyday activities. Such movements require a series of sensorimotor transformations that make use of visual, proprioceptive, and eye and arm position signals to plan and execute the coordinated responses that are typically observed. The ease with which humans are able to generate and control such responses belies the underlying complexity that is inherent in the planning process. This becomes apparent in patients with brain damage who typically have difficulty generating coordinated eye and hand movements, thus, leading to much greater dependence on caregivers and family members for support. The research taking place in my lab is designed to gain a better understanding of the neural mechanisms underlying the sensorimotor transformations associated with eye-hand coordination. My research team has investigated this using a combination of behavioural manipulations and perturbations to cortical processing induced with transcranial magnetic stimulation (TMS). A poorly understood component of eye-hand coordination is the predictive signals that guide the movements based on the anticipated sensory consequences of the motor output. In particular, it is unclear how and when these signals contribute to motor planning and which structures in the brain are responsible for doing so. Thus, the goals of the current proposal are to 1) directly probe the nature and timing of the predictive planning process using a combination of behavioural manipulations; and 2) use TMS to directly assess the contribution of several different brain structures in this process. Taken together, the experiments proposed in this application will allow us to better understand the temporal dynamics of predictive motor planning and how different brain regions contribute to this planning. This information can be used to better inform current theories of limb motor control.