Reinforcer pathologies: Predicting alcohol related problems in college drinking men and women.

BACKGROUND: Alcohol use in college is common, and problematic consequences of alcohol may affect college men and women differently. Approaches within behavioral economics have been used to improve our understanding of alcohol use in college students. METHODS: The current study assessed relations between college students' delay discounting, demand for alcohol, and alcohol problems as measured by the Young Adult Alcohol Consequences Questionnaire (YAACQ). In this study, 80 college drinkers completed a monetary choice questionnaire that assessed delay discounting of money, a novel beer choice questionnaire that evaluated delay discounting of beer, and an alcohol purchase task that measured demand for alcohol. RESULTS: Behavioral economic measures associated with the reinforcer pathologies model (i.e., demand and discounting) predicted alcohol consequences as measured by the YAACQ. For men, these significant predictor variables included money discounting, beer discounting, and intensity of alcohol demand, whereas for women money discounting and essential value were significant predictors. CONCLUSIONS: These findings highlight the utility of the reinforcer pathologies approach for the study of alcohol use and the importance of considering gender differences in examining college drinking.

Concurrent progressive ratio schedules: Effects of reinforcer probability on breakpoint and response allocation.

Although progressive ratio (PR) schedules have been used to explore effects of a range of reinforcer parameters (e.g., magnitude, delay), effects of reinforcer probability remain underexplored. The present project used independently progressing concurrent PR PR schedules to examine effects of reinforcer probability on PR breakpoint (highest completed ratio prior to a session terminating 300s pause) and response allocation. The probability of reinforcement on one lever remained at 100% across all conditions while the probability of reinforcement on the other lever was systematically manipulated (i.e., 100%, 50%, 25%, 12.5%, and a replication of 25%). Breakpoints systematically decreased with decreasing reinforcer probabilities while breakpoints on the control lever remained unchanged. Patterns of switching between the two levers were well described by a choice-by-choice unit price model that accounted for the hyperbolic discounting of the value of probabilistic reinforcers.

On the time course of rapid and repeatable response induction.

As reinforcers are delivered for a particular response, that response increases. Other similar responses also increase, with the extent to which this increase is seen being positively related to the similarity between the responses. This process, called induction, is pronounced during initial response acquisition, and dissipates as the target response is established. The present experiment examined this process in a paradigm wherein responses to one of five nose poke receptacles results in reinforcement for six sessions in each condition and the target location changes between conditions. Consistent patterns of induction were seen across conditions, with patterns of induction dissipating within each condition.