Spatially distributed patterns of oscillatory coupling between high-frequency amplitudes and low-frequency phases in human iEEG

►Using human intracranial EEG (iEEG) data, we provide evidence for multiple interacting sources being involved in phase-amplitude coupling (PAC). In fact, we show that the spatial maps for the coupling oscillations are much more widespread than the ones for the associated phase-coupled bursts. ►This evidence is provided by a novel analysis, involving a tensor decomposition of weighted phase locking factors that quantify the strength of the between-channel PAC. ►In the majority of the PAC patterns, phase-coupled bursts of high-frequency activity are synchronized across brain areas. ►Working memory operations affect the PAC strength in a heterogeneous way: in some PAC patterns, working memory operations increase their strength, whereas in others they decrease it.