Cognitively demanding tasks activate brain regions within the SN (eg, insula, dorsal anterior cingulate cortex) and ECN (eg, DLPFC) and deactivate regions of the DMN (eg, PCC, VMPFC).6,19,40 Alterations in coupling between these networks, and specifically the failure to suppress DMN activity, increase the probability of error on cognitive tasks.41,42 We extend these observations by demonstrating the predictive validity of a novel index (RAI) that combines the SN-DMN and SN-ECN correlation strength additively,there by reflecting concurrent adjustments in task-positive and task-negative activity that may be attributable to the detection of salient events and modulation of activity via the SN.The RAI should be more sensitive than individual paired network couplings(SN-DMNandSN-ECN),provided that the noise probability distribution functions in the individual indexes are not fully dependent.
