In order to control dosage of alcohol during the alcohol challenge, an intravenous administration paradigm was used consistent with previous work (Ray and Hutchison, 2004, Ray et al., 2006). Ethanol infusion sessions took place at the General Clinical Research Center at the University of Colorado at Boulder and were performed by registered nurses under the direct supervision of a physician. Target breath alcohol concentrations (BrACs) at which participants completed study measures were: 0.02, 0.04, and 0.06 g/dL. Upon reaching each of the target BrAC levels, participants’ infusion rates were reduced to half their rate, in order to maintain stable BrAC levels during the assessments. After the alcohol infusion was finished, participants were debriefed, given a meal, and asked to stay in the laboratory until their BrAC was below 0.02 g/dL.
