Frequency diversity of posterior oscillatory activity in human revealed by spatial filtered MEG.
Frequency diversity of posterior oscillatory activity in human revealed by spatial filtered MEG.
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空间滤波 MEG 显示人类后振荡活动的频率多样性。
DOI：
10.1142/s0219635213500209
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Takeda M.
中科院分区：
文献类型：
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作者：
Ishii R;Canuet L;Aoki Y;Ikeda S;Hata M;Takahashi H;Nakahachi T;Gunji A;Iwase M;Takeda M.
后部EEG α节律是清醒状态下正常大脑的独特特征，由后部皮质区域上的8-15 Hz频率范围内的振荡组成。这种活动出现在休息、闭眼的状态下，通常会被睁眼抑制。其他生理节奏的α带，特别是罗兰的μ节奏，提出了包括一个快速组件的β范围。在这项研究中，我们使用空间滤波技术和排列分析，探讨皮质源功率的变化相关的脑磁图（MEG）对应的后α节律。我们的目的还在于确定可能的影响成分以外的α频率范围内的后节律反应闭眼。我们使用全脑脑磁图系统记录了15名正常受试者的静息脑活动。我们采用了睁眼/闭眼模式。闭眼后，在双侧枕叶和顶叶皮质（包括距状裂和顶枕沟）中观察到α振荡显着增加，代表后部α节律。我们还发现β（15-30 Hz）和低γ（30-60 Hz）振荡显著增加。这种快成分与经典α节律在大脑后部区域的地形分布相似，但强度和空间范围不同。这些特征对于α同步振荡是最高的，对于β是中间的，并且对于γ活动是最低的。这些结果表明，像Rolandic μ节律，MEG后优势节律可能是不纯的，主要的α振荡和高频成分的混合物。
The posterior EEG alpha rhythm is a distinctive feature of the normal brain in the waking state, consisting of oscillations within the 8–15 Hz frequency range over posterior cortical regions. This activity appears in resting, eyes-closed condition and is typically suppressed by eyes-opening. Other physiological rhythms in the alpha band, in particular the Rolandic mu rhythm, are proposed to include a fast component in the beta range. In this study we used spatial filtering techniques and permutation analysis to explore cortical source-power changes related to the magnetoencephalography (MEG) counterpart of the posterior alpha rhythm. We also aimed at determining a possible implication of components outside the alpha frequency range in the posterior rhythm reactivity to eye closure. We recorded resting brain activity using a whole-head MEG system in fifteen normal subjects. We applied an eyes-open/eyes-closed paradigm. A significant increase in alpha oscillations after eyes closing, representing the posterior alpha rhythm, was observed bilaterally in the occipital and parietal cortex, including the calcarine fissure and the parieto-occipital sulcus. We also found significant increase in beta (15–30 Hz) and low gamma (30–60 Hz) oscillations. This fast components and the classical alpha rhythm had similar topographic distribution in posterior brain regions, although with different strength and spatial extension. These features were highest for alpha synchronized oscillations, intermediate for beta, and lowest for gamma activity. These results suggest that, like the Rolandic mu rhythm, the MEG posterior dominant rhythm may be impure, with a mixture of predominant alpha oscillations and high-frequency components.