在脑机接口研究中,针对运动想象脑电信号的特征提取,采用了一种优化的基于小波包的ICA(独立成分分析)法,用于提取大脑在想象动作时产生事件相关去同步/同步(Event Related Desynchronization or Event Related Synchronization ERD/ERS...在脑机接口研究中,针对运动想象脑电信号的特征提取,采用了一种优化的基于小波包的ICA(独立成分分析)法,用于提取大脑在想象动作时产生事件相关去同步/同步(Event Related Desynchronization or Event Related Synchronization ERD/ERS)信号。利用小波包对脑电信号进行分解去除不同脑电信号之间的统计相关性,抽取包含ERD/ERS现象的特征频带,对每个特征频带分别进行ICA分解,获取与ERD/ERS现象相关的μ节律和β节律。最后引入ERD/ERS系数作为量化指标进行想象动作的识别。分类仿真结果表明,上述方法能够显著增强运动想象脑电信号的ERD/ERS特征信息,对比与独立使用某一种方法,两种方法结合更能有效的提取脑电信号特征波。展开更多
The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. B...The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. By analyzing one group of BCI competition data, it was found that FSE within upper alpha band displays a pronounced increase and decrease over contralateral and ipsilateral brain areas respectively at the onset of hand motor imagery, which is corresponding to the antagonistic ERD/ERS patterns in previous studies. Different from the upper alpha activity pattern, FSE within lower alpha band displays a consistent increase over both two hemispheres hand representative areas. The preliminary results show that FSE could disclose the different behaviors of the upper and lower alpha band rhythms so that a new idea with the complexity measure is provided to characterize functional dissociation of lower and upper frequency alpha rhythms in relation to hand motor imagery.展开更多
目的:探究镜像诱导强化吞咽运动想象(motor imagery of swallowing,MIS)激活吞咽相关脑区的证据。方法:入组健康青年右利手受试者7例,使用青年男女吞咽视频作为刺激素材诱导吞咽运动想象,镜像诱导条件下的吞咽运动想象测次为试验组,无...目的:探究镜像诱导强化吞咽运动想象(motor imagery of swallowing,MIS)激活吞咽相关脑区的证据。方法:入组健康青年右利手受试者7例,使用青年男女吞咽视频作为刺激素材诱导吞咽运动想象,镜像诱导条件下的吞咽运动想象测次为试验组,无诱导的吞咽运动想象测次为对照组,每组各40个测次。应用脑磁图(MEG)检测不同条件下吞咽运动想象任务在全脑的事件相关同步/去同步(event-related synchronization/desynchronization,ERS/ERD)。结果:在0—10s的任务时间窗内,对照组和试验组在全脑水平均出现了大范围的ERS模式。相较于对照组,试验组吞咽相关部分脑区在α和β频带呈现更为显著的ERS模式。显著激活的脑区主要集中在双侧额叶和颞叶,少量出现于双侧枕叶和边缘叶、右侧顶叶及左侧岛叶。结论:与无诱导的吞咽运动想象训练相比,镜像刺激下的吞咽运动想象能够显著激活吞咽相关功能脑区,提示镜像诱导可能对吞咽运动想象具有启动效应,提升了训练的质量和效果,为吞咽运动想象在临床治疗中的应用和改进提供依据。展开更多
文摘在脑机接口研究中,针对运动想象脑电信号的特征提取,采用了一种优化的基于小波包的ICA(独立成分分析)法,用于提取大脑在想象动作时产生事件相关去同步/同步(Event Related Desynchronization or Event Related Synchronization ERD/ERS)信号。利用小波包对脑电信号进行分解去除不同脑电信号之间的统计相关性,抽取包含ERD/ERS现象的特征频带,对每个特征频带分别进行ICA分解,获取与ERD/ERS现象相关的μ节律和β节律。最后引入ERD/ERS系数作为量化指标进行想象动作的识别。分类仿真结果表明,上述方法能够显著增强运动想象脑电信号的ERD/ERS特征信息,对比与独立使用某一种方法,两种方法结合更能有效的提取脑电信号特征波。
基金National Natural Science Foundation of China (No.30370395and30670534)Chinese Post-doctoral Science Foundation (No.20070410380)
文摘The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. By analyzing one group of BCI competition data, it was found that FSE within upper alpha band displays a pronounced increase and decrease over contralateral and ipsilateral brain areas respectively at the onset of hand motor imagery, which is corresponding to the antagonistic ERD/ERS patterns in previous studies. Different from the upper alpha activity pattern, FSE within lower alpha band displays a consistent increase over both two hemispheres hand representative areas. The preliminary results show that FSE could disclose the different behaviors of the upper and lower alpha band rhythms so that a new idea with the complexity measure is provided to characterize functional dissociation of lower and upper frequency alpha rhythms in relation to hand motor imagery.
文摘目的:探究镜像诱导强化吞咽运动想象(motor imagery of swallowing,MIS)激活吞咽相关脑区的证据。方法:入组健康青年右利手受试者7例,使用青年男女吞咽视频作为刺激素材诱导吞咽运动想象,镜像诱导条件下的吞咽运动想象测次为试验组,无诱导的吞咽运动想象测次为对照组,每组各40个测次。应用脑磁图(MEG)检测不同条件下吞咽运动想象任务在全脑的事件相关同步/去同步(event-related synchronization/desynchronization,ERS/ERD)。结果:在0—10s的任务时间窗内,对照组和试验组在全脑水平均出现了大范围的ERS模式。相较于对照组,试验组吞咽相关部分脑区在α和β频带呈现更为显著的ERS模式。显著激活的脑区主要集中在双侧额叶和颞叶,少量出现于双侧枕叶和边缘叶、右侧顶叶及左侧岛叶。结论:与无诱导的吞咽运动想象训练相比,镜像刺激下的吞咽运动想象能够显著激活吞咽相关功能脑区,提示镜像诱导可能对吞咽运动想象具有启动效应,提升了训练的质量和效果,为吞咽运动想象在临床治疗中的应用和改进提供依据。
