Role of criticality in the structure-function relationship in the human brain

A healthy brain exhibits a rich dynamical repertoire, with flexible spatiotemporal patterns replaying on both microscopic and macroscopic scales. We hypothesize that the observed relationship between empirical structure and functional patterns is best explained when the microscopic neuronal dynamics is close to a critical regime. Using a modular spiking neuronal network model based on empirical connectomes, we posit that multiple stored functional patterns can transiently reoccur when the system operates near a critical regime, generating realistic brain dynamics and structural-functional relationships. The connections in the model are chosen so as to force the network to learn and propagate suited modular spatiotemporal patterns. To test our hypothesis, we employ magnetoencephalography and tractography data from five healthy individuals. We show that the extended critical region of the model maximizes the structure-function correlation and generates realistic features, demonstrating the relevance of near-critical regimes for physiological brain activity.