Synchronous Brain Dynamics Establish Brief States of Communality in Distant Neuronal Populations

Abstract Intrinsic brain dynamics co-fluctuate between distant regions in an organized manner during rest, establishing large-scale functional networks. We investigate these on a millisecond time scale by focusing electroencephalographic (EEG) source analyses. While synchrony is thought of as neuronal mechanism grouping populations into assemblies, the relevance simultaneous zero-lag synchronization areas humans remains largely unexplored. This negligence because confound volume conduction, leading inherently to temporal dependencies estimates derived from scalp EEG [and magnetoencephalography (MEG)], referred spatial leakage. Here, we focus analyses simultaneous, i.e., quasi related, that cannot be explained leakage phenomenon. In eighteen subjects rest with eyes closed, provide evidence first, present and second, this long-range occurring brief epochs, 54–80 ms. Simultaneous might signify convergence remote populations. Given simultaneity regions, patterns relate representation maintenance, rather than processing information. briefly stable, not persistently, indicating flexible reconfiguration pertaining establishment particular, re-occurring states. Taken together, suggest balance stability flexibility long-range, characteristic dynamic coordination As such, zero-phase related fluctuations are physiologically meaningful if considered appropriately.