Background. Motor imagery engages much of the same neural circuits as an overt movement. Therefore, the mental rehearsal of movements is often used to supplement physical training and might aid motor neurorehabilitation after stroke. One attempt to capture the brain’s involvement in imagery involves the use, as a marker, of the depression or event-related desynchronization (ERD) of thalamocortical sensorimotor rhythms found in a human electroencephalogram (EEG). Using fast real-time processing, it is possible to make the subject aware of their own brain reactions or—even better—to turn them into actions through a technology called the brain–computer interface (BCI). However, it remains unclear whether BCI-enabled imagery facilitates a stronger or qualitatively different brain response compared to the open-loop training. Methods. Seven healthy volunteers who were experienced in both closed and open-loop motor imagery took part in six experimental sessions over a period of 4.5 months, in which they performed kinesthetic imagery of a previously known set of finger and arm movements with simultaneous 30-channel EEG acquisition. The first and the last session mostly consisted of feedback trials in which the subjects were presented with the classification results of the EEG patterns in real time; during the other sessions, no feedback was provided. Spatiotemporal and amplitude features of the ERD patterns concomitant with imagery were compared across experimental days and between feedback conditions using linear mixed-effects modeling. Results. The main spatial sources of ERD appeared to be highly stable across the six experimental days, remaining nearly identical in five of seven subjects (Pearson’s ρ > 0.94). Only in one subject did the spatial pattern of activation statistically significantly differ (p = 0.009) between the feedback and no-feedback conditions. Real-time visual feedback delivered through the BCI did not significantly increase the ERD strength. Conclusion. The results imply that the potential benefits of MI could be yielded by well-habituated subjects with a simplified open-loop setup, e.g., through at-home self-practice.

中文翻译：

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实时反馈是否会影响常规运动想象练习中的感觉运动脑电图模式？

背景。运动意象与明显的运动有许多相同的神经回路。因此，运动的心理排练通常用于补充体能训练，并可能有助于中风后的运动神经康复。捕捉大脑参与图像的一种尝试涉及使用人类脑电图 (EEG) 中发现的丘脑皮层感觉运动节律的抑郁或事件相关不同步 (ERD) 作为标记。使用快速实时处理，可以让受试者意识到他们自己的大脑反应，或者——甚至更好——通过一种称为脑机接口 (BCI) 的技术将它们转化为行动。然而，与开环训练相比，启用 BCI 的图像是否会促进更强或质量上不同的大脑反应仍不清楚。方法。七名在闭环和开环运动意象方面都有经验的健康志愿者参加了为期 4.5 个月的六次实验，他们对一组先前已知的手指和手臂运动进行了动觉意象，同时进行了 30 通道 EEG获得。第一节和最后一节主要由反馈试验组成，其中实时向受试者呈现脑电图模式的分类结果；在其他会议期间，没有提供任何反馈。与图像相伴的 ERD 模式的时空和幅度特征在实验日之间和使用线性混合效应建模的反馈条件之间进行了比较。结果。ERD 的主要空间来源在六个实验日内似乎高度稳定，在七个科目中的五个科目中保持几乎相同（Pearson 的 ρ > 0.94）。只有在一个受试者中，激活的空间模式在统计学上有显着差异（p = 0.009) 在反馈和无反馈条件之间。通过 BCI 提供的实时视觉反馈并没有显着增加 ERD 强度。结论。结果表明，习惯良好的受试者可以通过简化的开环设置获得 MI 的潜在益处，例如，通过在家自我练习。