High-amplitude oscillatory events orchestrate cortical activity for efficient cognition

How do large-scale functional brain networks dynamically emerge to enable cognition? Correlated oscillations, a mechanism for inter-areal interactions, can be expressed as phase coherence or correlated amplitude fluctuations. However, little is known about whether and how the amplitude correlation of cortical oscillations can impact cognition. Here, we demonstrate that inter-areal amplitude coupling related to cognitive dynamics mainly reflects transient coincidences of high-amplitude oscillatory events, rather than sustained coupling of oscillations. Capitalizing on the spatio-temporal resolution of brain-wide magnetoencephalography (MEG) during a task probing attention and decision-making our findings reveal behaviorally relevant transient networks: First, coincidence of high-amplitude oscillatory events in the alpha and beta frequency range increases prior to correct decisions in a parieto-frontal network. Second, during attention allocation coincident high-amplitude events increase in visual, medial parietal and lateral prefrontal networks in the theta/alpha frequency range. We propose that the brain-wide orchestration of high-amplitude oscillatory events can facilitate inter-areal interactions supporting efficient cognition.