Brain states

Brain states are a ubiquitous topic of research in neuroscience, but differences in the scale of measurement and physiological or behavioral state of the subject have resulted in different definitions across subfields. In this article, we offer a definition of “brain state” as a quantifiable pattern of brain activity. We subsequently review the considerations of various measurement scales and outline steps for quantifying brain state dynamics through a network graph-theoretic approach. Additionally, we cover data-driven approaches for identifying recurrent brain states through time. Finally, we review methods that have been employed to examine important features of brain states that may be relevant for physiological function and cognitive behavior.