基于下肢运动想象的脑电节律研究

关键词：脑电图  运动想象  事件相关电位  事件相关去同步化与同步化

Keywords:electroencephalogram  motor imagery  event-related potentials  event-related desynchronization and synchronization

摘要：

      摘要 目的：通过脑电节律探究健康人下肢运动想象机制。 方法：选择20例健康被试完成下肢运动想象任务，对采集的脑电数据选择C3、C4、Cz通道分析其事件相关电位(event related potential， ERP)和事件相关去同步化与同步化(event-related desynchronization and synchronization， ERD/ERS)。 结果：①左右下肢运动想象在C3、Cz、C4产生几乎相同的ERP模式，左右下肢Cz通道波峰潜伏期为230ms，C3通道潜伏期为250ms，C4通道潜伏期为260ms，两侧下肢运动想象均能诱发P300；②左侧下肢ERP均值在C3通道高于C4通道，右侧下肢ERP均值在C4通道高于C3通道；③无论是C3通道还是C4通道，单侧通道左右下肢运动想象均表现为ERD，两侧下肢想象运动ERDα频段较β频段明显。 结论：左右下肢运动想象在两侧半球产生几乎相同的ERP模式和ERD，但下肢运动想象ERP均值出现同侧化。下肢运动想象诱发的P300可能和运动想象的注意和意图相关。本文研究成果可为下肢运动想象的脑机接口(brain-computer interface， BCI)设计开发提供有价值信息。

Abstract:

      Abstract Objective： To explore the lower limbs motor imagination mechanism in healthy people by EEG rhythms. Method： Twenty healthy subjects were selected to complete the lower limbs motor imaging tasks. EEG and ERP from C3， C4， Cz were picked and their ERP and event-related desynchronization and synchronization (ERD/ERS) were analyzed. Result： ①Both lower limbs motor imagination evoked almost the same ERP patterns in C3，Cz，and C4 channels.The Cz channel peak latency of lower limbs motor imagination is 230ms，the C3 channel peak latency is 250ms and the C4 channel peak latency is 260ms；②The ERP of the left lower limb motor imaging in the C3 channel is higher than the C4 channel， and the ERP of the right lower limb in the C4 channel is higher than in the C3 channel；③No matter in the C3 channel or the C4 channel，the lower limbs motor imagination presents ERD，and the lower limbs motor imagination ERD inαfrequency band is more obvious than in β frequency band. Conclusion： The lower limbs motor imagination presented almost the same ERP pattern and ERD in both hemispheres， However， the mean ERP of lower limbs motor imaging appears ipsilateral. P300 of lower limbs motor imagination may be related to the attention and intention. The research results can provide valuable information for the design and development of brain-computer interface for lower limb motor imagery.