Neural Mechanisms of Cutaneous Spatial Integration

本项目分析了顶叶体感神经元在熟练操作中的作用。 手动任务。它的目的是了解手如何通过感官获得关于物体的信息 触觉和本体感觉，并用它来抓住和操纵它们。我们使用理解任务，在这个任务中， 手抓住和操纵物体，作为一个模型系统来检查感官提示和之前的 经验被用来计划和实施熟练的手部行为。我们假设在主动触摸过程中， 感觉流入的内部表征是通过运动系统的必然放电来实现的 这样受试者就可以预测预期行为的感官后果。中环和中环的汇流 外周信号允许后顶叶皮质(PPC)的神经元比较预测和现实。这个 感觉反应是在任务目标的背景下被感知的。多电极记录的棘波序列和 S-I和PPC的局部场势以及手部运动学的测量，评估时间关系 代表手指的神经群体之间。我们认为PPC中的预见性接触前活动 反映了有效地抓取物体并确保它们可供操纵所需的任务规划。联系后 S-I的活动证实或反驳了受试者S对触觉特征的期望，并提供了所需的反馈 纠错。目标1通过改变信息来分析感觉反馈的自上而下的认知控制 由球杆提供。我们检查对象的形状和位置在PPC中是如何表示的 掌握了不同的指示和期望。目的2研究双侧手的神经控制 通过比较左手和右手执行的时间上不耦合的抓取动作和 类似的动作需要手的协调和协同动作。同时使用双侧 从左半球和右半球的记录来看，我们检查这种行为是否涉及每个半球的神经元 专门用于双手动作的半球，或通过同时激活两者来实现的 半个半球。目标3探讨了当线索不明确时，PPC在决策中的作用。我们评估 利手偏好、奖赏概率和短期记忆在用手选择中的作用 在每一次审判中抓住的对象。这项研究为大脑皮层的动态组织提供了基本见解 电路，预测在正常手部使用中的作用，以及体感信息在 手指精细运动控制所需的大脑半球。对这些皮质突起的了解可能 对中风或周围神经疾病后的康复具有临床重要性 受伤。从这项研究中得出的感觉运动集成原理可能被证明对更好地开发有用 基于手功能的生物模型的感官假体或机器人操作器。

This project analyzes the role of somatosensory neurons in the parietal lobe during performance of skilled manual tasks. It aims to understand how the hand acquires information about objects through the senses of touch and proprioception, and uses it to grasp and manipulate them. 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 behaviors. We hypothesize that during active touch, internal representations of the sensory inflow are implemented by corollary discharge from the motor system so that the subject can predict the sensory consequences of intended actions. Convergence of central and peripheral signals allows neurons in posterior parietal cortex (PPC) to compare predictions and reality. The sensory responses are perceived in the context of task goals. Multiple electrode recordings of spike trains and local field potentials in S-I and PPC, and measurements of hand kinematics, assess temporal relations between neural populations representing the fingers. We propose that anticipatory precontact activity in PPC reflects task planning needed to grasp objects efficiently and to secure them for manipulation. Post-contact activity in S-I confirms or rebuts the subject¿s expectation of haptic features, and provides feedback needed for error correction. Aim 1 analyzes top-down cognitive control of sensory feedback by varying information provided by the cue. We examine how the shape and location of an object are represented in PPC when it is grasped with different instructions and expectations. Aim 2 examines the neural control of bilateral hand movements by comparing temporally uncoupled grasping actions performed by the left and right hands, with similar movements that require coordinated, and synergistic actions of the hands. Using simultaneous bilateral recordings from left and right hemispheres, we examine whether such behaviors involve neurons in each hemisphere specialized for bimanual actions, or are implemented by synchronous activation of the two hemispheres. 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 fingers. 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.