Subjects were intravenously infused with either alcohol (6% vol/vol in half-normal saline) or saline (placebo) in a randomized order as previously described (Kareken et al., 2010; Bragulat et al., 2008). Infusion pump rates were computer-controlled, with infusion profiles customized for each individual to achieve the same time course of breath alcohol concentration (BrAC): A linear rise to 50 mg% in 10 min, followed by constant exposure at 50 mg% throughout the approximate 45 minute functional imaging protocol. The placebo infusion employed the same pump-rate profile to be used (or as previously used) in the individual's alcohol session, but infused only saline (see O'Connor et al., 1998; Plawecki et al., 2007; Ramchandani et al., 1999). BrAC was measured immediately after the subject's arrival at Indiana University's General Clinical Research Center, and outside the scanner room immediately after imaging while the IV pumps continued to run.
