Spatially and Temporally Distinct Encoding of Muscle and Kinematic Information in Rostral and Caudal Primary Motor Cortex.
Spatially and Temporally Distinct Encoding of Muscle and Kinematic Information in Rostral and Caudal Primary Motor Cortex.
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DOI：
10.1093/texcom/tgaa009
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发表时间：
2020-01-01
影响因子：
--
通讯作者：
Rossiter, Holly E
中科院分区：
文献类型：
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作者：
Kolasinski, James;Dima, Diana C;Rossiter, Holly E
人类运动皮层的组织原理并不遵循人体解剖图，而是遵循分布式表征结构，其中运动原语组合起来产生运动输出。灵长类动物的电生理记录和人类成像数据表明，M1 编码运动的运动学特征，例如关节位置和速度。然而，M1 对皮肤和本体感觉刺激表现出有据可查的感觉反应，引发了关于运动学运动表征起源的问题：它们是否与自上而下的运动控制相关，或者它们是运动过程中自下而上的感觉反馈的附带现象？在这里，我们提供了人类 M1 在产生各种自然手部动作期间运动学和肌肉信息在空间和时间上不同的编码的证据。利用高场功能磁共振成像和脑磁图的强大组合，空间和时间多元代表性相似性分析揭示了运动开始前 200 毫秒以上 M1 尾部区域的运动信息编码。相比之下，肌肉活动模式在运动开始后很久才被编码到更多的吻侧运动区域。我们提供了令人信服的证据，表明在运动产生之前，灵巧运动的自上而下控制涉及 M1 尾部区域的运动学表征。
The organizing principle of human motor cortex does not follow an anatomical body map, but rather a distributed representational structure in which motor primitives are combined to produce motor outputs. Electrophysiological recordings in primates and human imaging data suggest that M1 encodes kinematic features of movements, such as joint position and velocity. However, M1 exhibits well-documented sensory responses to cutaneous and proprioceptive stimuli, raising questions regarding the origins of kinematic motor representations: are they relevant in top-down motor control, or are they an epiphenomenon of bottom-up sensory feedback during movement? Here we provide evidence for spatially and temporally distinct encoding of kinematic and muscle information in human M1 during the production of a wide variety of naturalistic hand movements. Using a powerful combination of high-field functional magnetic resonance imaging and magnetoencephalography, a spatial and temporal multivariate representational similarity analysis revealed encoding of kinematic information in more caudal regions of M1, over 200ms before movement onset. In contrast, patterns of muscle activity were encoded in more rostral motor regions much later after movements began. We provide compelling evidence that top-down control of dexterous movement engages kinematic representations in caudal regions of M1 prior to movement production.