Dynamic fluctuations in integration and segregation within the human functional connectome

Higher brain function relies upon the ability to flexibly integrate information across specialized communities of macroscopic brain regions, but it is unclear how this mechanism manifests over time. Here we characterized patterns of time-resolved functional connectivity using resting state and task fMRI data from a large cohort of unrelated subjects. Our results demonstrate that dynamic fluctuations in network structure during the resting state transition between states of integrated and segregated network topology. These patterns were altered during task performance, demonstrating a higher level of integration that tracked with task complexity. Replication analyses demonstrated that the results were reproducible across sessions, sample populations and datasets. Together these results provide evidence for metastability in the brain's coordination between integration and segregation.