Complex systems ensure resilience through multiple controllers acting at rapid and slower timescales. The need for efficient information flow through complex systems encourages small-world network structures. On the basis of these principles, a group of regions associated with top-down control was examined. Functional magnetic resonance imaging showed that each region had a specific combination of control signals; resting-state functional connectivity grouped the regions into distinct 'fronto-parietal' and 'cingulo-opercular' components. The fronto-parietal component seems to initiate and adjust control; the cingulo-opercular component provides stable 'set-maintenance' over entire task epochs. Graph analysis showed dense local connections within components and weaker 'long-range' connections between components, suggesting a small-world architecture. The control systems of the brain seem to embody the principles of complex systems, encouraging resilient performance.
Bibliographical noteFunding Information:
We thank Francis M. Miezin and Steven M. Nelson for their suggestions and help with data analysis. We thank Marcus E. Raichle, Ronny A.T. Dosenbach, Jessica A. Church, Alecia C. Vogel and Yannic B.L. Dosenbach for helpful discussions. This work was supported by NIH grants NS41255 and NS46424 (S.E.P.), the John Merck Scholars Fund, the Burroughs-Wellcome Fund, the Dana Foundation (B.L.S.), the Ogle Family Fund (B.L.S.), a Washington University Chancellor's Graduate Fellowship (to D.A.F.) and a United Negro College Fund/Merck Graduate Science Research Dissertation Fellowship (to D.A.F.).