The correlation between the RAI and the WM task activation changes was investigated as in the performance model. The task-induced BOLD signal percentage change (dS/S) for each memory load was extracted from 5 regions of interest identified by a 2 (state) × 4 (memory load) analysis of variance, where dSnS=Sa,n−S0S0=βa,nβo,n×100%, n = 0b, 1b, 2b, 3b; Sa,n = βa,np(t) + β0,n + ε; and p(t) is the paradigm for the WM task. The 5 regions of interest consisted of 3 “task-positive” regions (dorsal anterior cingulate cortex [Talairach coordinates 0, 20, 43] and bilateral DLPFC [left, −44, 24, 23; right, 42, 30, 24], component regions seen in SN and ECN) and 2 “task-negative” regions (ventromedial prefrontal cortex [VMPFC] [−2, 40, −7] and PCC [−6, −55, 21], canonical DMN regions).6 The WM-related BOLD contrasts were normalized by subtracting the 0-back contrast from each load condition (ie, 1b – 0b, 2b – 0b, and 3b – 0b).
