Neural Mechanisms of Cutaneous Spatial Integration

描述（由申请人提供）：本项目分析了在熟练的手工任务的性能在顶叶的体感神经元的作用。我们使用一个任务，其中的手掌握和操纵对象，作为一个模型系统来研究如何使用感官线索和以前的经验来计划和实施熟练的手部动作。它旨在了解有关物体的信息是如何通过触觉，本体感觉和视觉的手获得的。我们建议，感觉反应的任务目标的背景下被认为是。后顶叶皮层（PPC）的神经活动被假设为反映任务规划需要有效地抓住物体，并确保他们的操作。初级躯体感觉（S-I）皮层中的神经反应确认或反驳受试者对物体特征的期望，并提供纠错所需的反馈。我们将使用多个电极阵列和手部运动学的数字视频测量记录PPC和S-I中神经群体的尖峰序列和局部场电位。目的1分析行为线索提供的感觉信息在调节神经元对刺激反应中的作用。我们研究如何在PPC中表示的对象的形状和位置时，它是掌握不同的指令和期望。这些研究验证了以下假设：对象特征的行为相关性修改了任务规划期间开发的运动程序，以及任务执行期间从手部反馈到皮层的体感信息。目标2解决了当双手一起执行相同动作时双侧手部动作的神经控制。我们将量化每个半球中双侧神经元的流行率，这些神经元对每只手执行的类似动作的反应相当，或者专门用于双手动作，通过比较由左手和右手分别执行的时间上解耦的抓握动作，与需要双手协调和协同动作的类似双手动作。我们还研究了双手行为是否是通过使用左右顶叶皮层的同时记录来实现两个半球的同步双侧激活的。目的3探索当线索模糊时，PPC在决策中的作用。我们评估了利手偏好，奖励概率和短期记忆在每次试验中使用的手和物体的选择中的作用。这项研究提供了基本的见解，皮质电路的动态组织，预测在正常的手的使用，和整合所需的精细运动控制的手半球之间的体感信息的作用。了解这些皮质过程可能对神经系统疾病（如中风或周围神经损伤）的康复具有临床重要意义。从这项研究中得出的感觉运动整合的原则可能被证明是有用的开发更好的感觉假肢或机器人操作手的生物模型的基础上。这个项目分析了在熟练的手工任务的表现过程中，大脑皮层顶叶神经元的作用。它的目的是了解有关物体的信息是如何通过触觉和本体感觉的手获得的，并由大脑使用时，物体被巧妙地抓住和操纵。这些脑机制的理解可能具有临床意义的手功能的神经系统疾病，如中风或周围神经损伤后的康复，并为开发更好的感觉假体或机器人操作手功能的生物模型的基础上。

DESCRIPTION (provided by applicant): This project analyzes the role of somatosensory neurons in the parietal lobe during performance of skilled manual tasks. We use a prehension task, in which the hand grasps and manipulates objects, as a model system to examine how sensory cues and previous experience are used to plan and implement skilled hand movements. It aims to understand how information about objects is acquired by the hand through the senses of touch, proprioception, and vision. We propose that sensory responses are perceived in the context of task goals. Neural activity in the posterior parietal cortex (PPC) is hypothesized to reflect task planning needed to grasp objects efficiently and to secure them for manipulation. Neural responses in the primary somatosensory (S-I) cortex confirms or rebuts the subject's expectation of object features, and provides feedback needed for error correction. We will record spike trains and local field potentials of neural populations in PPC and S-I during performance of the task using multiple electrode arrays and digital video measurements of hand kinematics. Aim 1 analyzes the role of sensory information provided by the behavioral cue in modulating neural responses to prehension. We examine how the shape and location of an object are represented in PPC when it is grasped with different instructions and expectations. The studies test hypotheses that the behavioral relevance of object features modifies the motor program developed during task planning, and somatosensory information fed back to the cortex from the hand during task performance. Aim 2 addresses the neural control of bilateral hand movements when both hands perform the same movements together. We will quantify the prevalence of bilateral neurons in each hemisphere that respond equivalently to similar actions performed by each hand, or are specialized for bimanual actions, by comparing temporally uncoupled grasping movements performed separately by the left and right hands, with similar bimanual movements that require coordinated and synergistic actions of the two hands. We also examine whether bimanual behaviors are implemented by synchronous bilateral activation of the two hemispheres using simultaneous recordings from the left and right parietal cortex. Aim 3 explores the role of PPC in decision making when cues are ambiguous. We assess the role of handedness preferences, reward probability and short-term memory in choice of the hand used and object grasped in each trial. This research provides basic insights into the dynamic organization of cortical circuits, the role of prediction in normal hand use, and integration of somatosensory information between hemispheres needed for fine motor control of the hand. An understanding of these cortical processes may have clinical importance for rehabilitation following neurological disorders such as stroke or peripheral nerve injury. Principles of sensorimotor integration derived from this research may prove useful for developing better sensory prostheses or robotic manipulators based on biological models of hand function. This project analyzes the role of neurons in the parietal lobe of the cerebral cortex during performance of skilled manual tasks. It aims to understand how information about objects is acquired by the hand through the senses of touch and proprioception, and is used by the brain when objects are grasped and manipulated skillfully. An understanding of these brain mechanisms may have clinical importance for rehabilitation of hand function following neurological disorders such as stroke or peripheral nerve injury, and for development of better sensory prostheses or robotic manipulators based on biological models of hand function.