“…Cocaine choice for both unit doses decreased when the money alternative amount was larger ($3) compared to when it was smaller ($1); this finding is consistent with results from preclinical studies (Nader and Woolverton, 1991; Nader et al, 1993; Woolverton et al, 1997; Rodefer et al, 1997; Peitz et al, 2013), human laboratory studies (Donny et al, 2003, 2004; Higgins et al, 1994a; Stoops et al, 2012) and clinical trials (Higgins et al, 1991, 1994b, 2000, 2007; Petry et al, 2004; Rothfleisch et al, 1999), which supports the validity of this study and provides a platform for the more novel investigation of reinforcement probability.…”