Nonlinear features of surface EEG showing systematic brain signal adaptations with muscle force and fatigue.
Nonlinear features of surface EEG showing systematic brain signal adaptations with muscle force and fatigue.
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DOI：
10.1016/j.brainres.2009.03.042
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发表时间：
2009-05-26
期刊：
影响因子：
2.9
通讯作者：
Yue GH
中科院分区：
文献类型：
--
作者：
Yao B;Liu JZ;Brown RW;Sahgal V;Yue GH
非线性动力学已经被引入到生物数据的分析中，并且越来越多地被认为是功能相关的。本研究的目的是研究人类头皮脑电信号的混沌特性与自愿运动任务使用的最大李雅普诺夫指数（L1）。64-记录了8名健康受试者在两个任务中的20、40、60和80%的最大随意收缩（MVC）的间歇性握力收缩，每个水平20次试验。未诱导显著疲劳;（2）导致显著疲劳的间歇性手柄MVC（100次试验）。首先在每次试验中计算所有EEG通道的L1值，然后在获得组平均值之前，在每个力水平下（任务1）或在5个试验区组中的每个区组（任务2）上对20次试验取平均值。使用多变量统计模型来检查力和疲劳对L1的影响。L1值随力的增大而增大（任务1），随疲劳而显著降低（任务2）。EEG信号的L1发生系统性变化，并与肌肉力量和疲劳显著相关。结果表明，非线性混沌指数L1可以作为运动控制相关的皮层信号适应的定量测量。
Nonlinear dynamics has been introduced to the analysis of biological data and increasingly recognized to be functionally relevant. The purpose of this study was to examine chaotic properties of human scalp EEG signals associated with voluntary motor tasks using the largest Lyapunov exponent (L1). 64-channel scalp EEG data were recorded from eight healthy subjects in two tasks: (1) Intermittent handgrip contractions at 20, 40, 60, and 80% of maximal voluntary contraction (MVC) with 20 trials at each level. No significant fatigue were induced; (2) intermittent handgrip MVCs (100 trials) that resulted in significant fatigue. The L1 values of all EEG channels were calculated in each trial first then averaged across the 20 trials at each force level (Task 1) or over each of the 5-trial blocks (Task 2) before the group means were obtained. A multivariate statistical model was used to examine the effect of force and fatigue on L1. L1 values were greater with higher force (Task 1), and decreased significantly with fatigue (Task 2). The L1 of the EEG signals changes systematically and correlates significantly with muscle force and fatigue. The results suggest that nonlinear chaotic index L1 may serve as a quantitative measure for motor control-related cortical signal adaptations.
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DOI：
10.1016/s0013-4694(97)00079-5
发表时间：
1998-03-01
期刊：
ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY
影响因子：
--
作者：
Jeong, J;Kim, SY;Han, SH
通讯作者：
Han, SH
影响因子：
2.7
作者：
Kotini, A;Anninos, P
通讯作者：
Anninos, P
影响因子：
2.5
作者：
DETTMERS, C;FINK, GR;FRACKOWIAK, RSJ
通讯作者：
FRACKOWIAK, RSJ
影响因子：
2.4
作者：
Andrzejak, RG;Lehnertz, K;Elger, CE
通讯作者：
Elger, CE
影响因子：
2.5
作者：
Ehrsson, HH;Fagergren, A;Forssberg, H
通讯作者：
Forssberg, H