Residual coherence and residual envelope correlation in MEG/EEG source-space connectivity analysis.
Residual coherence and residual envelope correlation in MEG/EEG source-space connectivity analysis.
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DOI：
10.1109/embc.2013.6610525
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Nagarajan SS
中科院分区：
文献类型：
--
作者：
Sekihara K;Nagarajan SS
源空间相干性分析已成为基于 MEG/EEG 估计功能连接的流行方法。一个严重的问题是源空间相干性分析可能会因所采用的逆算法的泄漏特性而引起的杂散相干性被混淆。在生成的相干图像中，这种虚假相干性通常表现为种子体素周围的人为大峰值，称为种子模糊。这种种子模糊常常掩盖了大脑相互作用的重要细节。首次提出了一种计算相干性的新方法，称为残余相干性，以消除由成像算法泄漏引起的杂散相干性。然后，我们提出了理论分析，表明所提出的残余相干性与其他人提出的校正虚相干性之间的等价性。接下来，我们扩展了残余相干性的概念，并提出了残余包络相关性，它适用于估计高频大脑活动的连接性。计算机模拟的结果证明了残余相干性和残余包络相关性的有效性。
Source-space coherence analysis has become a popular method to estimate functional connectivity based on MEG/EEG. One serious problem is that source-space coherence analysis can be confounded by spurious coherence caused due to the leakage properties of the inverse algorithm employed. Such spurious coherence is typically manifested as an artifactual large peak around the seed voxel, called seed blur, in the resulting coherence images. This seed blur often obscures important details of brain interactions. A novel method of computing coherence, called the residual coherence, is first proposed to remove the spurious coherence caused by the leakage of an imaging algorithm. We then present a theoretical analysis that shows the equivalence between the proposed residual coherence and corrected imaginary coherence proposed by others. We next extend the idea of residual coherence, and propose residual envelope correlation, which is suitable for estimating connectivity from high-frequency brain activities. Results from computer simulations demonstrate the effectiveness of the residual coherence and the residual envelope correlation.