d'Avella Andrea, Saltiel Philippe, Bizzi Emilio
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology, 45 Carleton St., Cambridge, Massachusetts 02139, USA.
Nat Neurosci. 2003 Mar;6(3):300-8. doi: 10.1038/nn1010.
A central issue in motor control is how the central nervous system generates the muscle activity patterns necessary to achieve a variety of behavioral goals. The many degrees of freedom of the musculoskeletal apparatus provide great flexibility but make the control problem extremely complex. Muscle synergies--coherent activations, in space or time, of a group of muscles--have been proposed as building blocks that could simplify the construction of motor behaviors. To evaluate this hypothesis, we developed a new method to extract invariant spatiotemporal components from the simultaneous recordings of the activity of many muscles. We used this technique to analyze the muscle patterns of intact and unrestrained frogs during kicking, a natural defensive behavior. Here we show that combinations of three time-varying muscle synergies underlie the variety of muscle patterns required to kick in different directions, that the recruitment of these synergies is related to movement kinematics, and that there are similarities among the synergies extracted from different behaviors.
运动控制中的一个核心问题是中枢神经系统如何产生实现各种行为目标所需的肌肉活动模式。肌肉骨骼系统的多个自由度提供了极大的灵活性，但也使控制问题极其复杂。肌肉协同作用——一组肌肉在空间或时间上的连贯激活——被认为是可以简化运动行为构建的基本要素。为了评估这一假设，我们开发了一种新方法，用于从许多肌肉活动的同步记录中提取不变的时空成分。我们使用这项技术分析了完整且不受约束的青蛙在踢腿（一种自然防御行为）过程中的肌肉模式。我们在此表明，三种随时间变化的肌肉协同作用的组合构成了向不同方向踢腿所需的各种肌肉模式的基础，这些协同作用的募集与运动运动学相关，并且从不同行为中提取的协同作用之间存在相似性。
