Studies of subjective responses during rising and falling limbs of the BrAC curve are complicated when oral dosing is used because individuals show significant variation in rise, peak and fall of BrAC (Ramchandani et al., 1999). Intravenous (IV) infusion of alcohol, based on an individual’s physiologically-based pharmacokinetic parameters, assures identical BrAC trajectories among subjects by circumventing absorption kinetics and compensating for individual variation in distribution and elimination kinetics (Plawecki et al., 2008; Ramchandani et al., 1999). The improved control of BrAC available with IV infusion may provide better resolution of how subjective effects are affected by BrAC trajectories. Using IV infusion, our lab was able to measure subjective perceptions in subjects at an identical BrAC and time elapsed while BrAC was either rising or falling at prescribed rates of change (Wetherill et al., 2012). Subjects with recent moderate social drinking (mean and SEM 2.4±0.2 drinking days in the past 7 days) reported greater feelings of intoxicated and high on the ascending compared to descending slope, while recent light social drinkers (mean and SEM 1.9 ±0.4 drinking days in the past
