initial pattern of hyperconnectivity, which has indeed been demonstrated in paradigm-related MEG connectivity studies (Sun et al., 2013), could in time be followed by the diffuse deficit seen in chronic patients. Comparison with other EEG studies (see for review Boutros et al., 2008) is even more complex due to methodological differences such as beta band having been analyzed as one or more sub-components. It has been postulated that communication within the fronto-parieto-temporal attentional network is characterized by transient long-range phase synchronization in the beta-band (Schnitzler and Gross, 2005); the diffuse alterations seen in LDD (hyperconnectivity in beta1 and hypoconnectivity in beta2) may be different expressions of the same dysfunction in attentional and salience-related networks. Interestingly at molecular level, beta oscillations and coherence have been linked with GABA-B-R1 Gene Polymorphism in healthy individuals (Winterer et al., 2003). Since GABAergic transmission is profoundly impaired in schizophrenia (Schmidt and Mirnics, 2015), future EEG-SFC studies could investigate if beta-band disconnectivity may be considered as an intermediate phenotype of GABAergic dysfunction at system level.
