Functional connectivity was assessed using psychophyisiological interaction (PPI) analysis (Friston et al., 1997; Gitelman et al., 2003) which measures coupling of brain regions during specific task conditions. As described by O’Reilly et al. (2012) PPI analysis seeks to identify task-specific changes in the relationship between brain areas (i.e., functional connectivity). As such, if two areas interact more in the context of a certain psychological task (e.g., alcohol cue exposure), activity in one area should regress more strongly on activity in the other area during task blocks compared to during control blocks (O'Reilly et al., 2012). To examine fronto-striatal functional connectivity during cue exposure, we separately examined the coupling of (a) the right ventral striatum (including the nucleus accumbens) and (b) the dorsal striatum (caudate) and the rest of the brain during Alcohol- versus Water-cue presentation. The right ventral striatum as well as the caudate regions of interest (ROIs) were anatomically defined using the high-resolution MPRAGE anatomical images, segmented on a subject-specific basis in native space using FMRIB's Integrated Registration and Segmentation Tool (FIRST) in FSL. The average time course of
