Resting-state connectivity, for example, based on magnetoencephalography (MEG) or electroencephalography (EEG), is a widely used method for characterizing brain networks and a promising imaging biomarker. However, there is no established standard as to which method, modality, and analysis variant is preferable and there is only limited knowledge on the reproducibility, an important prerequisite for clinical application. We conducted an MEG-/high-density (hd)-EEG-study on 22 young healthy adults, who were measured twice in a scan/rescan design after 7 ± 2 days. Reliability of resting-state (15 min, eyes-closed) connectivity in source space was calculated via intraclass correlation coefficient (ICC) in classical frequency bands (delta-gamma). We investigated the reliability of two commonly used connectivity metrics, namely the imaginary part of coherency and the weighted phase-lag index and the influence of frequency band, vigilance, and the number of trials. We found a strong increase of reliability with more trials and relatively mild effects of vigilance. Reliability was excellent in the alpha band for MEG, as well as hd-EEG (ICC >0.85); in the theta band, reliability was good for MEG and poor for EEG. Other frequency bands showed lower reliability, with delta band being the worst. Furthermore, we investigated the spatial reliability of resting-state connectivity in a vertex-based approach, which reached fair to good reliability (ICC up to 0.67) with 5 min of data. Our results indicate that excellent reliability of global connectivity is achievable in alpha band, and vertex-based connectivity was still fair to good. Moreover, electrophysiological resting-state studies could benefit from more data than used previously. MEG and hd-EEG were similar in their overall performance but showed frequency band-specific differences.

中文翻译：

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磁脑电图和高密度脑电图静息状态功能连接性度量标准的可靠性。

例如，基于磁脑电图（MEG）或脑电图（EEG）的静态连接是一种广泛使用的表征脑部网络和有希望的成像生物标记物的方法。但是，尚无关于哪种方法，方法和分析方法更可取的标准，并且对可重复性的认识有限，可重复性是临床应用的重要前提。我们对22位健康的年轻人进行了MEG /高密度（hd）-EEG研究，这些成年人在7±2天后通过扫描/重新扫描设计进行了两次测量。通过经典频带（δ-γ）中的类内相关系数（ICC）计算源空间中静止状态（15分钟，闭眼）连接的可靠性。我们调查了两个常用连接性指标的可靠性，即相干性的虚部和加权的相位滞后指数，以及频带，警惕性和试验次数的影响。我们发现，通过进行更多的试验以及提高警惕性，可以大大提高可靠性。对于MEG和hd-EEG（ICC> 0.85），alpha波段的可靠性极佳；在θ带中，可靠性对MEG良好，对EEG较差。其他频段显示出较低的可靠性，其中增量频段最差。此外，我们以基于顶点的方法研究了静态连接的空间可靠性，该方法在5分钟的数据下达到了相当好的可靠性（ICC高达0.67）。我们的结果表明，在alpha波段中可以实现出色的全局连接可靠性，而基于顶点的连接仍然是公平的。此外，电生理静息状态研究可从比以前使用的更多数据中受益。MEG和hd-EEG的整体性能相似，但显示出特定于频段的差异。