In this review, we also show examples of applications of phase coupling methods to MEG data from different cognitive domains. Of note, in these studies, connectivity results were disentangled from power results proving evidence for a genuine phase coupling between brain areas. Moreover, in the resting state and in the visuospatial attention examples, the MEG connectivity results have been supported by MRI functional or anatomical connectivity. While the benefits of integrating different modalities in the study of functional connectivity by MEG is self-evident, still actual multimodal connectivity analysis tools are lacking. Along the same line, a comprehensive characterization of the benefits and/or limitations in the integration procedures is missing. One example of integrating MEG functional connectivity with MRI information is the recent characterization of the impact of MEG-MRI coregistration errors in functional connectivity estimated through different metrics (Chella et al., 2019).
