Source cancellation profiles of electroencephalography and magnetoencephalography.
Source cancellation profiles of electroencephalography and magnetoencephalography.
复制标题
脑电图和磁脑摄影的来源取消概况。
DOI：
10.1016/j.neuroimage.2011.08.104
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发表时间：
2012-02-01
期刊：
影响因子：
5.7
通讯作者：
Halgren, Eric
中科院分区：
文献类型：
--
作者：
Irimia, Andrei;Van Horn, John Darrell;Halgren, Eric
由于皮层电活动而记录的电势和磁场具有空间扩散，即使它们的潜在脑源是焦点。因此，作为源抵消的结果，当分布式源同时活动时，可以预期信号幅度的损失和有效信噪比的降低。在这里，我们调查的消除效果的EEG和MEG通过使用解剖学上正确的前向模型的基础上获得的结构MRI从7个健康成年人。生成了具有四个隔室（脑、脑脊液、颅骨和头皮）和高度精确的皮质网格（约300，000个顶点）的边界元模型（BEM）。分布式源激活模拟使用连续补丁的有源偶极子。为了研究EEG和MEG中的抵消效应，定义了定量指标（源增强，皮质方向差异），并计算了补丁半径的不同值以及自动包裹的脑回和脑沟。计算每个皮质位置的结果，使用概率图谱对所有受试者进行平均，并在MEG和EEG之间进行定量比较。正如预期的那样，MEG传感器被发现是最敏感的信号，由于源切向头皮，和最低限度的敏感径向源。然而，与EEG相比，MEG被发现对前内侧产生的信号更敏感，特别是在前扣带回。鉴于激活源根据皮层的方向差异相互抵消，本研究提供了有用的方法和结果，量化的源的方向差异后源取消的影响。
Recorded electric potentials and magnetic fields due to cortical electrical activity have spatial spread even if their underlying brain sources are focal. Consequently, as a result of source cancellation, loss in signal amplitude and reduction in the effective signal-to-noise ratio can be expected when distributed sources are active simultaneously. Here we investigate the cancellation effects of EEG and MEG through the use of an anatomically correct forward model based on structural MRI acquired from 7 healthy adults. A boundary element model (BEM) with four compartments (brain, cerebrospinal fluid, skull and scalp) and highly accurate cortical meshes (~300,000 vertices) were generated. Distributed source activations were simulated using contiguous patches of active dipoles. To investigate cancellation effects in both EEG and MEG, quantitative indices were defined (source enhancement, cortical orientation disparity) and computed for varying values of the patch radius as well as for automatically parcellated gyri and sulci. Results were calculated for each cortical location, averaged over all subjects using a probabilistic atlas, and quantitatively compared between MEG and EEG. As expected, MEG sensors were found to be maximally sensitive to signals due to sources tangential to the scalp, and minimally sensitive to radial sources. Compared to EEG, however, MEG was found to be much more sensitive to signals generated antero-medially, notably in the anterior cingulate gyrus. Given that sources of activation cancel each other according to the orientation disparity of the cortex, this study provides useful methods and results for quantifying the effect of source orientation disparity upon source cancellation.
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影响因子：
5.7
作者：
Fischl, B;Sereno, MI;Dale, AM
通讯作者：
Dale, AM
影响因子：
--
作者：
Lachaux, JP;Rudrauf, D;Kahane, P
通讯作者：
Kahane, P
DOI：
10.1016/s0013-4694(98)00057-1
发表时间：
1998-08-01
期刊：
ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY
影响因子：
--
作者：
Leahy, RM;Mosher, JC;Lewine, JD
通讯作者：
Lewine, JD
影响因子：
1.7
作者：
Chainay, H;Krainik, A;Lehéricy, S
通讯作者：
Lehéricy, S
影响因子：
5.7
作者：
Dale, AM;Fischl, B;Sereno, MI
通讯作者：
Sereno, MI