EEG default mode network in the human brain: Spectral regional field powers
EEG default mode network in the human brain: Spectral regional field powers
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DOI：
10.1016/j.neuroimage.2007.12.064
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发表时间：
2008-06-01
期刊：
影响因子：
5.7
通讯作者：
Wang, Peipei
中科院分区：
文献类型：
--
作者：
Chen, Andrew C. N.;Feng, Weijia;Wang, Peipei
闭眼（EC）和睁眼（EO）是人类的基本行为，在静息EC-EO状态下，fMRI研究发现脑活动处于无任务需求的默认模式。然而，尽管EEG在人类中被记录了近80年，但相应的综合电生理条件却知之甚少。在这项研究中，我们研究了EEG场功率谱分布的空间特征，即，对15名右利手健康女大学生进行了安静静坐、EC和EO各3 min的静息状态下的高密度128-chEEG记录和FFT信号分析。感兴趣区域被设置在光谱有效值的90%处的阈值处，以界定大脑活动中有效能量的主导空间场功率。低频δ（0.5- 3.5Hz）脑电场功率主要分布在额前区，从EC状态到EO状态，空间场扩大，场功率增强（t =-2.72，p < 0.02）。Theta（4-7 Hz）脑电场功率分布于额中央区，从EC到EO状态前倾，但场功率急剧降低（t = 4.04，p < 0.01）。中频α-1（7.5-9.5 Hz）和α-2（10-12 Hz）EEG功率在较低α-1的后部区域上表现出双侧分布。两者均显示从EC到EO状态的场功率显著降低（分别为，W = 120，α-1，p < 0.001; t = 4.12，α-2，p < 0.001）。β-1（13-23 Hz）在后部区域上显示出与α-2相似的空间区域，并显示出从EC到EO状态的场功率降低（t = 4.42，p < 0.001）。相比之下，高频β-2和γ波段表现出相似的，主要是在场功率的前额分布，并表现出从EC到EO状态没有变化。相应的相关分析表明，EC和EO仅在δ（r = 0.95，p < 0.001）和θ（r = 0.77，p < 0.001）波段的场功率上存在显著的组关联。此外，在受试者中，EC状态（10倍）下观察到局部场功率的个体间变异性（α-1的90倍，α-2的62倍）大于EO状态。总之，我们的研究描绘了一个网络的频谱EEG活动，同时在EC状态下定义明确的区域字段，具体EC和EO状态之间的变化。与瞬态脑电频谱节律动力学相反，目前对长持续（e。G. 3 min）谱场功率可以表征脑电的状态特征。脑电默认模式网络（EEG-DMN）的频谱场功率在休息时在各自的EC或EO状态的价值，作为在人脑中的基础电生理条件。在健康方面，该EEG-DMN被认为对于在没有性别差异、年龄跨度的发育变化和大脑对任务激活的反应的任务需求的情况下评估大脑功能是必不可少的。预期它将定义静息状态下疾病中的脑功能障碍，并对人脑中的感觉、情感和认知改变产生影响。(C)2008年由Elsevier Inc.出版
Eyes-closed (EC) and eyes-open (EO) are essential behaviors in mammalians, including man. At resting EC-EO state, brain activity in the default mode devoid of task-demand has recently been established in fMRI. However, the corresponding comprehensive electrophysiological conditions are little known even though EEG has been recorded in humans for nearly 80 years. In this study, we examined the spatial characteristics of spectral distribution in EEG field powers, i.e., sitting quietly with an EC and EO resting state of 3 min each, measured with high-density 128-ch EEG recording and FFT signal analyses in 15 right-handed healthy college females. Region of interest was set at a threshold at 90% of the spectral effective value to delimit the dominant spatial field power of effective energy in brain activity. Low-frequency delta (0.5-3.5 Hz) EEG field power was distributed at the prefrontal area with great expansion of spatial field and enhancement of field power (t = -2.72, p < 0.02) from the EC to the EO state. Theta (4-7 Hz) EEG field power was distributed over the fronto-central area and leaned forward from EC to the EO state but with drastic reduction in field power (t = 4.04, p < 0.01). The middle-frequency alpha-1 (7.5-9.5 Hz) and alpha-2 (10-12 Hz) EEG powers exhibited bilateral distribution over the posterior areas with an anterior field in lower alpha-1. Both showed significantly reduction of field powers (respectively, W = 120, p < 0.001 for alpha-1; t = 4.12, p < 0.001 for alpha-2) from EC to the EO state. Beta-1 (13-23 Hz) exhibited a similar spatial region over the posterior area as in alpha-2 and showed reduction of field power (t = 4.42, p < 0.001) from EC to the EO state. In contrast, high-frequency beta-2 and gamma band exhibited similar, mainly prefrontal distribution in field power, and exhibited no change from EC to the EO state. Corresponding correlation analyses indicated significant group association between EC and EO only in the field powers of delta (r = 0.95, p < 0.001) and theta (r = 0.77, p < 0.001) band. In addition, the great inter-individual variability (90 folds in alpha-1, 62 folds in alpha-2) in regional field power was largely observed in the EC state (10 folds) than the EO state in subjects. To summarize, our study depicts a network of spectral EEG activities simultaneously operative at well defined regional fields in the EC state, varying specifically between EC and EO states. In contrast to transient EEG spectral rhythmic dynamics, current study of long-lasting (e. g. 3 min) spectral field powers can characterize state features in EEG. The EEG default mode network (EEG-DMN) of spectral field powers at rest in the respective EC or EO state is valued to serve as the basal electrophysiological condition in human brain. In health, this EEG-DMN is deemed essential for evaluation of brain functions without task demands for gender difference, developmental change in age span, and brain response to task activation. It is expected to define brain dysfunction in disease at resting state and with consequences for sensory, affective and cognitive alteration in the human brain. (C) 2008 Published by Elsevier Inc.