Neural and electromyographic correlates of wrist posture control.
Neural and electromyographic correlates of wrist posture control.
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手腕姿势控制的神经和肌电图相关性。
DOI：
10.1152/jn.01160.2006
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发表时间：
2007
影响因子：
2.5
通讯作者：
Scheidt,RobertA
中科院分区：
文献类型：
--
作者：
Suminski,AaronJ;Rao,StephenM;Mosier,KristineM;Scheidt,RobertA
在相同的实验和MR扫描仪，我们记录了功能磁共振成像和肌电图相关的手腕稳定对恒定和随时间变化的机械扰动。定位误差最大，而稳定的随机扭矩。腕部肌肉活动滞后于关节角速度的变化，在lasting-trans-cortex反射作用。漂移稳定的手的位置引起了频繁的，准确地定向，纠正运动，这表明大脑保持所需的手腕角度的反馈控制的姿势和离散校正的产生单独的表示。两种模式的神经活动是明显的血氧水平依赖（BOLD）的时间序列稳定期间获得的。一个小脑丘脑皮层网络表现出显着的活动，只要位置错误。在这里，激活的变化与位置误差（而不是力）的每时每刻的变化相关，暗示这个网络在手位置的反馈控制中。第二个网络，显示升高的活动在稳定的错误是否存在，包括前额叶皮层，喙背运动前区和辅助运动区皮层，以及顶叶皮层的下方面。在这些区域中的一些区域中的BOLD激活与在较长时间范围内整合的定位误差相关，这与通过调整行为目标（反馈设定点）以及规划和执行内部生成的运动动作来优化反馈性能一致。非重叠网络在不同的时间尺度上表现出对运动学性能误差的不同敏感性的发现支持了这样一个假设，即在稳定手的过程中，大脑招募不同的神经系统来反馈控制肢体位置和评估/调整控制器参数以应对持续的误差。
In identical experiments in and out of a MR scanner, we recorded functional magnetic resonance imaging and electromyographic correlates of wrist stabilization against constant and time-varying mechanical perturbations. Positioning errors were greatest while stabilizing random torques. Wrist muscle activity lagged changes in joint angular velocity at latencies suggestingtrans-cortical reflex action. Drift in stabilized hand positions gave rise to frequent, accurately directed, corrective movements, suggesting that the brain maintains separate representations of desired wrist angle for feedback control of posture and the generation of discrete corrections. Two patterns of neural activity were evident in the blood-oxygenation-level-dependent (BOLD) time series obtained during stabilization. A cerebello-thalamo-cortical network showed significant activity whenever position errors were present. Here, changes in activation correlated with moment-by-moment changes in position errors (not force), implicating this network in the feedback control of hand position. A second network, showing elevated activity during stabilization whether errors were present or not, included prefrontal cortex, rostral dorsal premotor and supplementary motor area cortices, and inferior aspects of parietal cortex. BOLD activation in some of these regions correlated with positioning errors integrated over a longer time-frame consistent with optimization of feedback performance via adjustment of the behavioral goal (feedback setpoint) and the planning and execution of internally generated motor actions. The finding that nonoverlapping networks demonstrate differential sensitivity to kinematic performance errors over different time scales supports the hypothesis that in stabilizing the hand, the brain recruits distinct neural systems for feedback control of limb position and for evaluation/adjustment of controller parameters in response to persistent errors.