The dosing procedure that "makes the poison": Comparing the effects of single versus cumulative alcohol administration methods on emotion recognition

Background: Most people often consume alcohol cumulatively and gradually. Yet almost scientific knowledge about alcohol's acute effects on cognition, behavior, and affect stems from laboratory studies that employ a single beverage administration procedure. Objective: This study tests the hypothesis that alcohol's acute effects depend on both methods of administration and alcohol blood level. We introduce a new laboratory procedure for studying cumulative alcohol drinking and examine alcohol's effects on emotion recognition as a function of both alcohol administration method and alcohol blood level. Methods: Participants were recruited for one of two studies. One study employed a between-subject design using a single alcoholic dose. Participants were randomly assigned to drink either placebo (0.00%), low (0.03%), moderate (0.06%), or high (0.09%) alcohol levels. The second study employed a within-subject design using a cumulative alcoholic administration method, in which each participant drank four drinks (placebo, followed by three alcoholic drinks). Both groups reached similar breath alcohol concentrations. In both studies, participants attended a single study session, in which emotion recognition was examined following alcohol administration. Results: Single alcoholic beverage administration method caused greater impairment in emotion recognition ability, specifically for anger, happiness, and fear, as compared with cumulative administration method, even though breath alcohol levels were similar in both conditions. Conclusions: This paper presents questions concerning the internal validity of previous laboratory studies that use a single beverage administration procedure. Insights into the effects of alcohol on behavior, as well as regarding our knowledge about models of addiction are presented.