Joint cross-correlation analysis reveals complex, time-dependent functional relationship between cortical neurons and arm electromyograms.
Joint cross-correlation analysis reveals complex, time-dependent functional relationship between cortical neurons and arm electromyograms.
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DOI：
10.1152/jn.00031.2013
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发表时间：
2014-12
影响因子：
2.5
通讯作者：
K. Zhuang;M. Lebedev;M. Nicolelis
中科院分区：
文献类型：
--
作者：
K. Zhuang;M. Lebedev;M. Nicolelis
皮质活动与肢体肌肉肌电图（EMG）活动之间的相关性长期以来一直是神经生理学研究的主题，特别是在皮质脊髓连接方面。由于具有模仿肌肉力量的输出信号的脑机接口的发展，人们对这个问题的兴趣最近有所增加。在这项研究中，三只猴子的多个皮质区域被植入了多电极阵列。一只猴子执行自动定时触摸板按压操作，而另外两只则执行手臂伸展动作。我们使用联合互相关（JCC）分析来分析皮质神经元活动和手臂肌电图之间的动态关系，该分析将逐个试验的相关性评估为试验内时间间隔的函数。 JCC 揭示了多块肌肉的肌电图与运动、前运动和体感皮质区域的神经活动之间的短暂相关性。匹配结果是通过减去试验改组数据而校正的尖峰触发平均值获得的。与尖峰触发平均值相比，JCC 更容易揭示皮质-肌电图相关性的动态变化。 JCC 表明，相关峰值通常在运动时间附近变尖，并在延迟间隔期间变宽。此外，JCC 模式对于手臂伸展任务是有方向选择性的。我们建议，未来生成类似肌电图信号的脑机接口应该考虑皮质活动和肌电图之间这种高度动态、任务依赖和分布式的关系。
Correlation between cortical activity and electromyographic (EMG) activity of limb muscles has long been a subject of neurophysiological studies, especially in terms of corticospinal connectivity. Interest in this issue has recently increased due to the development of brain-machine interfaces with output signals that mimic muscle force. For this study, three monkeys were implanted with multielectrode arrays in multiple cortical areas. One monkey performed self-timed touch pad presses, whereas the other two executed arm reaching movements. We analyzed the dynamic relationship between cortical neuronal activity and arm EMGs using a joint cross-correlation (JCC) analysis that evaluated trial-by-trial correlation as a function of time intervals within a trial. JCCs revealed transient correlations between the EMGs of multiple muscles and neural activity in motor, premotor and somatosensory cortical areas. Matching results were obtained using spike-triggered averages corrected by subtracting trial-shuffled data. Compared with spike-triggered averages, JCCs more readily revealed dynamic changes in cortico-EMG correlations. JCCs showed that correlation peaks often sharpened around movement times and broadened during delay intervals. Furthermore, JCC patterns were directionally selective for the arm-reaching task. We propose that such highly dynamic, task-dependent and distributed relationships between cortical activity and EMGs should be taken into consideration for future brain-machine interfaces that generate EMG-like signals.