The software calculated projected aBAC in the background, adjusting projected aBAC profiles with each BrAC entry. A safety ceiling of 100mg% was imposed, such that drink requests were not possible if the next button press would yield a projected aBAC >100mg%. During these intervals the button deactivated until a drink could be delivered without aBAC exceeding 100mg% (yielding a maximum of ~7.5 min before the next request was allowed). Additional details on the Freibier paradigm are provided elsewhere (Zimmermann et al., 2008, 2009, 2013).
