broadband criticality of human brain network synchronization人类的大脑网络的宽带临界同步.pdf

Broadband Criticality of Human Brain Network Synchronization 1 2 3 1,3 Manfred G. Kitzbichler , Marie L. Smith , Søren R. Christensen , Ed Bullmore * 1 Behavioural Clinical Neurosciences Institute, Departments of Experimental Psychology and Psychiatry, University of Cambridge, Cambridge, United Kingdom, 2 MRC Cognition and Brain Sciences Unit, Cambridge, United Kingdom, 3 Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke’s Hospital, Cambridge, United Kingdom Abstract Self-organized criticality is an attractive model for human brain dynamics, but there has been little direct evidence for its existence in large-scale systems measured by neuroimaging. In general, critical systems are associated with fractal or power law scaling, long-range correlations in space and time, and rapid reconfiguration in response to external inputs. Here, we consider two measures of phase synchronization: the phase-lock interval, or duration of coupling between a pair of (neurophysiological) processes, and the lability of global synchronization of a (brain functional) network. Using computational simulations of two mechanistically distinct systems displaying complex dynamics, the Ising model and the Kuramoto model, we show that both synchronization metrics have power law probability distributions specifically when these systems are in a critical state. We then demonstrate power law scaling of both pairwise and global synchronization metrics in functional MRI and magnetoencephalographic data recorded from normal volunteers under resting conditions. These results strongly suggest that human brain functional systems exist in an endogenous state of dynamical criticality, characterize