Cortical networks for control of voluntary arm movements under variable force conditions
Cortical networks for control of voluntary arm movements under variable force conditions
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DOI：
10.1093/cercor/8.1.48
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发表时间：
1998-01-01
期刊：
影响因子：
3.7
通讯作者：
Grossberg, S
中科院分区：
文献类型：
--
作者：
Bullock, D;Cisek, P;Grossberg, S
建立了一个自主运动和本体感觉的神经模型，为灵长类动物皮层运动相关区域中不同类型细胞的功能作用提供了一个综合解释。模型电路保持准确的本体感觉，同时控制自主到达空间目标，对障碍物施加力，在扰动下保持姿势，遵守强加的运动，以及静态和惯性负载补偿。计算机模拟表明，模式元素的属性与区域4和5中许多已知细胞类型的属性相对应。这些特性包括延迟期激活、运动时的反应曲线、运动学和动力学敏感性以及活动开始的潜伏期。特别是，第4区相性和强直性细胞分别计算能够激活α和γ运动神经元的速度和位置命令，从而改变机械平衡点。前5区细胞利用4区的必然放电和肌肉纺锤波的反馈来计算肢体的位置。后5区神经元使用位置感知信号和目标位置信号来计算期望的运动向量。皮层回路通过意志门控的运动向量投射到4区相细胞闭合。辅助电路允许4区的相位-张力细胞结合所需的力指挥组件来补偿静态和惯性负载。在报告了先前实验结果的模拟之后，在新的实验协议下对运动和顶叶细胞类型进行了预测。
A neural model of voluntary movement and proprioception is developed that offers an integrated interpretation of the functional roles of diverse cell types in movement-related areas of primate cortex. The model circuit maintains accurate proprioception while controlling voluntary reaches to spatial targets, exertion of force against obstacles, posture maintenance despite perturbations, compliance with an imposed movement, and static and inertial load compensations. Computer simulations show that properties of model elements correspond to the properties of many known cells types in areas 4 and 5. Among these properties are delay period activation, response profiles during movement, kinematic and kinetic sensitivities, and latency of activity onset. In particular, area 4 phasic and tonic cells, respectively, compute velocity and position commands that are capable of activating alpha and gamma motor neurons, thereby shifting the mechanical equilibrium point. Anterior area 5 cells compute the position of the limb using corollary discharges from area 4 and feedback from muscle spindles. Posterior area 5 neurons use the position perception signal and a target position signal to compute a desired movement vector. The cortical loop is closed by a volition-gated projection of this movement vector to the area 4 phasic cells. An auxiliary circuit allows phasic-tonic cells in area 4 to incorporate force command components needed to compensate for static and inertial loads. After reporting simulations of prior experimental results, predictions are made for both motor and parietal cell types under novel experimental protocols.