Given the absence of an external task during recording, the functional interpretation of EEG power and coherence at rest has posed a challenge for researchers. One approach has been to establish a relationship between EEG and MRI or cognitive measures. For example, DMN activation and resting EEG across frequencies are positively correlated, (Laufs et al. 2003; Mantini et al. 2007; Jann et al. 2010; Fingelkurts and Fingelkurts 2011), and EEG band power predicts variance in functional connectivity within the DMN (Hlinka et al. 2010). The convergence of findings from EEG and fMRI studies indicate that synchronization of neural activity may provide the scaffolding for mental activity and cognitive processing (Varela et al. 2001; Ward, 2003). Of relevance, aberrant activation of several regions in the DMN and resting state networks have been shown in SZ (Whitfield-Gabrieli et al. 2009; Ongür et al. 2010; Chai et al. 2011; Wolf et al. 2011) and BP (Ongür et al. 2010; Chai et al. 2011). Given these findings, we now discuss several key issues within our data.
