Are You Afraid of the Dark Matter? Making Sense of Fluctuating Brain Activity

Most of the brain’s activity occurs in the absence of direct stimuli, leading researchers to talk about the "dark energy" of the brain. This spontaneous activity is not merely an epiphenomenon, but contributes to both mental and behavioural processes. In this talk, I discuss several domains where spontaneous brain activity influences neuronal communication, development, and cognitive outcomes. These domains span human neuroimaging, multicellular recordings, as well as computational simulations of brain activity. Taken together, evidence on the key role of spontaneous activity fosters a new approach to understanding the brain, one that focuses on intrinsic dynamics and revises the classic view of synaptic networks as strict input-output systems. Finally, I highlight some of the fundamental principles that form the pillars for the emerging field of complex brain dynamics.