Instantaneous and causal connectivity in resting state brain networks derived from functional MRI data

►In resting state, regions whose activities are not instantaneously synchronized, interact via time-delayed causal influences ►The bi-directional causal interactions at rest are organized such that cingulo-parietal regions act as hubs ►Unidirectional causal paths revealed that hippocampus and anterior prefrontal cortex (aPFC) receive major inputs, likely reflecting memory encoding/retrieval and cognitive integration, respectively ►Major outputs emanating from anterior insula and middle temporal area, which are directed at aPFC, may carry information about interoceptive awareness and external environment, respectively, into aPFC for integration, supporting the hypothesis that aPFC-seeded FPCN acts as a control network ►Segregation of different resting state networks is not clear cut but only by soft boundaries