Alpha rhythm shapes the correlation landscape of avalanche dynamics across resting wakefulness

Brain rhythms and neuronal avalanches form a fascinating dichotomy in the universe of emergent brain dynamics. The former have characteristic times and amplitudes, whereas the latter are scale-free, i.e. they lack characteristic spatio-temporal scales. Yet, they coexist and can be independently measured across different physiologic states, such as sleep and resting wake. However, underlying dynamics and functional role of such emergent dichotomy, as well as the dynamic relationship between brain rhythms and avalanches, remain not understood. In this talk I will show that, while the scale-free properties are universal and preserved across sleep and wake, avalanche dynamics is intimately connected to the dominant brain rhythm characterizing each of those physiologic states, and shows unique features in the resting awake state. Our results indicate that the alpha rhythm induces a dynamic transition in the functional organization of neuronal avalanches, and crucially determines the relationship between consecutive avalanches to balance the spatio-temporal dynamics of spontaneous brain activity.