Shared and specific muscle synergies in natural motor behaviors
Shared and specific muscle synergies in natural motor behaviors
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DOI：
10.1073/pnas.0500199102
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发表时间：
2005-02-22
影响因子：
11.1
通讯作者：
Bizzi, E
中科院分区：
文献类型：
--
作者：
d'Avella, A;Bizzi, E
由于搜索空间的维数以及肌肉活动和运动之间转换的非线性和动态性，选择合适的肌肉模式来实现给定的目标是一项极其复杂的任务。为了研究中枢神经系统是否使用模块化结构来实现运动协调，我们对大量运动的运动输出进行了表征。我们记录了在自然条件下正常自由活动的青蛙在跳跃、游泳和行走过程中后肢13块肌肉的肌电图活动。我们使用多维因子分解技术来提取肌肉激活之间的不变振幅和时间关系。将瞬时肌肉激活分解为非负矢量的组合，同步肌肉协同作用，揭示了肌肉模式的空间组织。将相同的激活分解为非负矢量的时间序列组合，时变肌肉协同作用，进一步揭示了肌肉激活波形的特定特征。跨行为共享的协同作用和特定行为的协同作用的混合捕获了整个数据集的不变性。这些结果支持了电机控制器具有模块化组织的假设。
Selecting the appropriate muscle pattern to achieve a given goal is an extremely complex task because of the dimensionality of the search space and because of the nonlinear and dynamical nature of the transformation between muscle activity and movement. To investigate whether the central nervous system uses a modular architecture to achieve motor coordination we characterized the motor output over a large set of movements. We recorded electromyographic activity from 13 muscles of the hind limb of intact and freely moving frogs during jumping, swimming, and walking in naturalistic conditions. We used multidimensional factorization techniques to extract invariant amplitude and timing relationships among the muscle activations. A decomposition of the instantaneous muscle activations as combinations of nonnegative vectors, synchronous muscle synergies, revealed a spatial organization in the muscle patterns. A decomposition of the same activations as a combination of temporal sequences of nonnegative vectors, time-varying muscle synergies, further uncovered specific characteristics in the muscle activation waveforms. A mixture of synergies shared across behaviors and synergies for specific behaviors captured the invariances across the entire dataset. These results support the hypothesis that the motor controller has a modular organization.