Group Analysis Performed at Baseline (see Paulus et al., 2012): Anatomically-constrained functional regions of interest (ROIs) were based on a priori hypotheses regarding regions of interest in the insular cortex, medial prefrontal cortex (mPFC), and amygdala based on the Talairach Atlas (Lancaster et al., 2000). A voxel-based mixed-model analysis with fixed effects of emotion type (happy, angry, fearful), group (low and high LR), education, and response latency, with the random effects as subjects was carried out. Thirteen functionally refined clusters within these anatomical regions were defined (the volume and coordinates of the centroids in Talairach space are given in Table 2). The volume minimum for these functional ROIs were determined through threshold adjustment based on Monte Carlo simulations (conducted via AFNIs in Alpha Sim, a threshold p of .05, two-tailed) guarded against identifying false positive areas of activation. Percent signal change for the contrasts of interest were extracted from each of the 13 previously defined ROIs (Paulus et al., 2012; Table 2) and used in the statistical analysis. All analyses covaried for both cerebral blood flow (CBF) (overall blood flow differences in ml/100g/min for placebo vs. alcohol sessions) and for usual drinks per occasion.
