Neuronal activity in sensory and fronto-parietal (FP) areas underlies the representation and attentional control, respectively, of sensory information maintained in visual working memory (VWM). Within these regions, beta/gamma phase-synchronization supports the integration of sensory functions, while synchronization in theta/alpha bands supports the regulation of attentional functions. A key challenge is to understand which mechanisms integrate neuronal processing across these distinct frequencies and thereby the sensory and attentional functions. We investigated whether such integration could be achieved by cross-frequency phase synchrony (CFS). Using concurrent magneto- and electroencephalography, we found that CFS was load-dependently enhanced between theta and alpha–gamma and between alpha and beta-gamma oscillations during VWM maintenance among visual, FP, and dorsal attention (DA) systems. CFS also connected the hubs of within-frequency-synchronized networks and its strength predicted individual VWM capacity. We propose that CFS integrates processing among synchronized neuronal networks from theta to gamma frequencies to link sensory and attentional functions.

source data 1Effect Size/Correlation Coefficients and p-values for CFS patch-patch interactionssource data 2Effect sizes and p-values for group statistics of recomputed cross-frequency amplitude-amplitude correlations.source data 3CFS Interaction matrices for Mean condition, pos. Tailsource data 4CFS Interaction matrices for Load condition, pos. Tailsource data 5Alpha-beta CFS Interaction matrices, pos. Tailsource data 6CFS Interaction matrices for Mean condition, neg. Tailsource data 7Effect Size/Correlation Coefficients and p-values for PAC patch-patch interactions