be interpreted with caution (Kaplan et al., 2014). The evidence indicates that phase coupling within different frequency bands plays a role in WM processes. Siebenhühner et al. (2016) expanded the perspective by showing that during the maintenance period of DMS task, cross-frequency coupling (assessed by PLVn:m) was enhanced above baseline between high-alpha and beta and gamma band oscillations. Similarly, cross-frequency coupling between high-theta and alpha, beta and gamma band oscillations were enhanced in contrast to baseline. The strength of the cross-frequency coupling of theta and high-alpha with their corresponding higher frequencies was also positively correlated with the VWM load and predicted inter-individual variability in VWM capacity. The hubs characterized by low-frequency oscillation were located predominantly in the frontoparietal and to a lesser extent in dorsal attention areas. The low frequency oscillations exhibited by these hubs were coupled with faster oscillations in the visual system and dorsal attention areas. In contrast, the higher frequency oscillations had hubs pre-dominantly in dorsal attention areas and in the visual cortex (gamma band). Moreover, the most central hubs involved in the cross-frequency coupling were co-localized with the most central hubs involved in the slow and fast within frequency coupling. These results suggest that cross-frequency coupling
