IntroductionBrain computer interface-based action observation (BCI-AO) is a promising technique in detecting the user's cortical state of visual attention and providing feedback to assist rehabilitation. Peripheral nerve electrical stimulation (PES) is a conventional method used to enhance outcomes in upper extremity function by increasing activation in the motor cortex. In this study, we examined the effects of different pairings of peripheral nerve electrical stimulation (PES) during BCI-AO tasks and their impact on corticospinal plasticity.Materials and methodsOur innovative BCI-AO interventions decoded user's attentive watching during task completion. This process involved providing rewarding visual cues while simultaneously activating afferent pathways through PES. Fifteen stroke patients were included in the analysis. All patients underwent a 15 min BCI-AO program under four different experimental conditions: BCI-AO without PES, BCI-AO with continuous PES, BCI-AO with triggered PES, and BCI-AO with reverse PES application. PES was applied at the ulnar nerve of the wrist at an intensity equivalent to 120% of the sensory threshold and a frequency of 50 Hz. The experiment was conducted randomly at least 3 days apart. To assess corticospinal and peripheral nerve excitability, we compared pre and post-task (post 0, post 20 min) parameters of motor evoked potential and F waves under the four conditions in the muscle of the affected hand.ResultsThe findings indicated that corticospinal excitability in the affected hemisphere was higher when PES was synchronously applied with AO training, using BCI during a state of attentive watching. In contrast, there was no effect on corticospinal activation when PES was applied continuously or in the reverse manner. This paradigm promoted corticospinal plasticity for up to 20 min after task completion. Importantly, the effect was more evident in patients over 65 years of age.ConclusionThe results showed that task-driven corticospinal plasticity was higher when PES was applied synchronously with a highly attentive brain state during the action observation task, compared to continuous or asynchronous application. This study provides insight into how optimized BCI technologies dependent on brain state used in conjunction with other rehabilitation training could enhance treatment-induced neural plasticity.

中文翻译：

---

动作观察过程中注意状态同步外周电刺激引起中风后皮质脊髓可塑性的明显调节

简介基于脑机接口的动作观察（BCI-AO）是一种很有前途的技术，可以检测用户视觉注意力的皮层状态并提供反馈以协助康复。周围神经电刺激 (PES) 是一种传统方法，用于通过增加运动皮层的激活来增强上肢功能的结果。在这项研究中，我们研究了 BCI-AO 任务​​期间不同配对的周围神经电刺激 (PES) 的效果及其对皮质脊髓可塑性的影响。材料和方法我们创新的 BCI-AO 干预措施解码了用户在任务完成过程中的注意力观察。这个过程涉及提供有益的视觉线索，同时通过 PES 激活传入通路。分析中包括 15 名中风患者。所有患者在四种不同的实验条件下接受了 15 分钟的 BCI-AO 程序：无 PES 的 BCI-AO、连续 PES 的 BCI-AO、触发 PES 的 BCI-AO 以及应用反向 PES 的 BCI-AO。 PES 以相当于感觉阈值 120% 的强度和 50 Hz 的频率应用于腕部尺神经。该实验是随机进行的，间隔至少三天。为了评估皮质脊髓和周围神经的兴奋性，我们比较了四种条件下受影响手部肌肉的运动诱发电位和 F 波的任务前和任务后（0 后、20 分钟后）参数。当PES与AO训练同步应用时，在注意力集中的状态下使用BCI时，受影响的半球更高。相比之下，连续或反向应用PES对皮质脊髓激活没有影响。这种范例在任务完成后长达 20 分钟内促进皮质脊髓可塑性。重要的是，这种效果在65岁以上的患者中更为明显。结论结果表明，与连续或异步应用相比，在动作观察任务期间与高度专注的大脑状态同步应用PES时，任务驱动的皮质脊髓可塑性更高。这项研究深入了解了依赖于大脑状态的优化脑机接口技术与其他康复训练结合使用如何增强治疗引起的神经可塑性。