Effects of alcohol on variability-contingent reinforcement in human subjects

Subjects responded under LAG-5 reinforcement conditions after consuming alcohol in table wine (0.4 g/kg ethanol). For reinforcement (points), a four-response sequence from two buttons was required which differed from the previous five sequences of four responses. In addition, some subjects responded under restricted conditions in which sequences were limited to those of moving a cursor within a 3 x 3 matrix, while other subjects had no such restrictions. Also some subjects worked alone while others were accompanied by an experimenter. Analysis showed that compared to controls, men in the unrestricted condition who received alcohol showed increased uncertainty in responding while comparable women receiving alcohol showed a decrease in uncertainty of responding. The results are discussed in terms of previous work on alcohol and behavioral variability.