Planning and Updating in Frontoparietal Networks for Grasping

描述（由申请人提供）：脑损伤（如中风或创伤性损伤）后发生的许多行为后遗症可以通过感觉信息和运动指令整合的异常来解释。该项目使用脑成像和非侵入性脑刺激，结合机器人和虚拟环境中抓取运动的新扰动，研究额顶叶脑区在感觉运动整合的不同阶段所扮演的角色，并确定大脑网络的具体贡献，以帮助目标导向的抓取。该项目的总体目标是使用健康的人类病变模型，对额顶皮层在感觉运动整合的两个主要阶段中所扮演的角色进行因果推断：在运动规划期间当目标的视觉信息和手的触觉信息被转换成运动命令时，以及在运动更新期间，当运动命令的感觉结果的估计发生时（生成前向模型）。我们利用了久经考验的方法，涉及扰动的目标和手臂电机厂（扰动的外在和内在的空间），已被用来研究感觉运动的整合达到系统，并应用它们来研究掌握电路，这是由一个独特的和隔离的神经网络，是比较欠研究。这是第一个系统的研究，在人类中测试的独特贡献额顶叶皮层的规划和前向建模的手形抓，以及这些过程如何相互作用的背景下，内在与外在的参考框架。目标1的中心目标是使用功能性磁共振成像（fMRI）来识别外部与内部空间中运动规划的神经基础，并相应地测试这些区域与经颅磁刺激引起的fMRI神经导航短暂病变的因果关系。目的2补充了先前的目的，通过测试的因果关系参与抓相关的额顶叶区在线更新的把握。在这里，我们利用多变量分析的运动学反应的新扰动的手的配置和运动目标，在把握解离参与这些领域的手形与集成到运动计划的前向模型的生成。

DESCRIPTION (provided by applicant): A number of the behavioral sequelae that occur after damage to the brain, such as stroke or traumatic injury, can be explained by abnormalities in the integration of sensory information and motor commands. This project uses brain imaging and non-invasive brain stimulation, combined with novel perturbations of grasping movements with robotics and virtual environments to study the roles played by frontoparietal brain areas in different stages of sensorimotor integration and to identify specific contributions of brain networks subserving goal-directed grasping. The overarching goal of this project is use a healthy-human lesion model to make causal inferences regarding the roles played by frontoparietal cortices in two major stages of sensorimotor integration: during motor planning when visual information of the target goal and haptic information of the hand is transformed into motor commands, and during movement updating when estimates of the sensory consequences of motor commands occur (generation of a forward model). We leverage the time-tested approaches involving perturbations to the target goal and the arm motor plant (perturbations of extrinsic and intrinsic space) that have been used to study sensorimotor integration in the reach system, and apply them to study the grasp circuit, which is controlled by a unique and segregated neural network that is comparatively understudied. This is the first systematic study in humans to test the unique contributions of frontoparietal cortices in planning and forward modeling of hand shape for grasping, and how these processes interact in the context of intrinsic versus extrinsic reference frames. The central goal of Aim 1 is to use functional magnetic resonance imaging (fMRI) to identify the neural bases of motor planning in external vs. internal space and accordingly test the causal involvement of these regions with fMRI-neuronavigated transient lesions elicited with transcranial magnetic stimulation. Aim 2 complements the previous aim by testing the causal involvement of grasp-related frontoparietal areas in online updating of grasp. Here, we leverage multivariate analyses of kinematic responses to novel perturbations of hand configuration and movement goals during grasping to dissociate the involvement of these areas in generation of forward models for hand shape versus integrating sensory information into the motor plan.