Instantaneous and Causal Connectivity in Resting State Brain Networks Derived from FMRI Data

Gopikrishna Deshpande¹, Priya Santhanam¹, Xiaoping Hu¹

Granger causality, though not requiring a priori assumptions, is influenced by the zero-lag correlation in resting state networks (RSNs) such as default mode (DMN), hippocampal cortical memory (HCMN), dorsal attention (DAN) and fronto-parietal control (FPCN) networks. We simultaneously derived functional and effective connectivities in these RSNs using correlation-purged Granger causality, a measure capable of reliably inferring causality without interference from correlation. Our results show extensive causal interactions between RSNs with the posterior cingulate and inferior parietal areas acting as major transit hubs. In addition, our results also support the role of FPCN in the control of DMN and DAN.