Individual differences in discount rate are associated with demand for self‐administered cocaine, but not sucrose

Substance abusers, including cocaine abusers, discount delayed rewards to a greater extent than do matched controls. In the current experiment, individual differences in discounting of delayed rewards in rats (choice of one immediate over three delayed sucrose pellets) were assessed for associations with demand for either sucrose pellets or an intravenous dose of 0.1 mg/kg/infusion cocaine. Twenty‐four male Sprague Dawley rats were split into three groups based on sensitivity to delay to reinforcement. Then, demand for sucrose pellets and cocaine was determined across a range of fixed‐ratio values. Delay discounting was then reassessed to determine the stability of this measure over the course of the experiment. Individual differences in impulsive choice were positively associated with elasticity of demand for cocaine, a measure of reinforcer value, indicating that rats having higher discount rates also valued cocaine more. Impulsive choice was not associated with the level of cocaine consumption as price approached 0 or with any parameter associated with demand for sucrose. Individual sensitivity to delay was correlated with the initial assessment when reassessed at the end of the experiment, although impulsive choice increased for this cohort of rats as a whole. These findings suggest that impulsive choice in rats is positively associated with valuation of cocaine, but not sucrose.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95135/1/adb361.pd

Stuck in Time: Negative Income Shock Constricts the Temporal Window of Valuation Spanning the Future and the Past

Insufficient resources are associated with negative consequences including decreased valuation of future reinforcers. To determine if these effects result from scarcity, we examined the consequences of acute, abrupt changes in resource availability on delay discounting-the subjective devaluation of rewards as delay to receipt increases. In the current study, 599 individuals recruited from Amazon Mechanical Turk read a narrative of a sudden change (positive, neutral, or negative) to one\u27s hypothetical future income and completed a delay discounting task examining future and past monetary gains and losses. The effects of the explicit zero procedure, a framing manipulation, was also examined. Negative income shock significantly increased discounting rates for gains and loses occurring both in the future and the past. Positive income windfalls significantly decreased discounting to a lesser extent. The framing procedure significantly reduced discounting under all conditions. Negative income shocks may result in short-term choices

Choice Bundling Increases Valuation of Delayed Losses More Than Gains in Cigarette Smokers

Choice bundling, in which a single choice produces a series of repeating consequences over time, increases valuation of delayed monetary and non-monetary gains. Interventions derived from this manipulation may be an effective method for mitigating the elevated delay discounting rates observed in cigarette smokers. No prior work, however, has investigated whether the effects of choice bundling generalize to reward losses. In the present study, an online panel of cigarette smokers (N = 302), recruited using survey firms Ipsos and InnovateMR, completed assessments for either monetary gains or losses (randomly assigned). In Step 1, participants completed a delay-discounting task to establish Effective Delay 50 (ED50), or the delay required for an outcome to lose half of its value. In Step 2, participants completed three conditions of an adjusting-amount task, choosing between a smaller, sooner (SS) adjusting amount and a larger, later (LL) fixed amount. The bundle size (i.e., number of consequences) was manipulated across conditions, where a single choice produced either 1 (control), 3, or 9 consequences over time (ascending/descending order counterbalanced). The delay to the first LL amount in each condition, as well as the intervals between all additional SS and LL amounts (where applicable), were set to individual participants’ ED50 values from Step 1 to control for differences in discounting of gains and losses. Results from Step 1 showed significantly higher ED50 values (i.e., less discounting) for losses compared to gains (p \u3c 0.001). Results from Step 2 showed that choice bundling significantly increased valuation of both LL gains and losses (p \u3c 0.001), although effects were significantly greater for losses (p \u3c 0.01). Sensitivity analyses replicated these conclusions. Future research should examine the potential clinical utility of choice bundling, such as development of motivational interventions that emphasize both the bundled health gains associated with smoking cessation and the health losses associated with continued smoking

Behavioral Economic Measurement of Cigarette Demand: A Descriptive Review of Published Approaches to the Cigarette Purchase Task

The cigarette purchase task (CPT) is a behavioral economic method for assessing demand for cigarettes. Growing interest in behavioral correlates of tobacco use in clinical and general populations as well as empirical efforts to inform policy has seen an increase in published articles employing the CPT. Accordingly, an examination of the published methods and procedures for obtaining these behavioral economic metrics is timely. The purpose of this investigation was to provide a review of published approaches to using the CPT. We searched specific Boolean operators ([“behavioral economic” AND “purchase task”] OR [“demand” AND “cigarette”]) and identified 49 empirical articles published through the year 2018 that reported administering a CPT. Articles were coded for participant characteristics (e.g., sample size, population type, age), CPT task structure (e.g., price framing, number and sequence of prices; vignettes, contextual factors), and data analytic approach (e.g., method of generating indices of cigarette demand). Results of this review indicate no standard approach to administering the CPT and underscore the need for replicability of these behavioral economic measures for the purpose of guiding clinical and policy decisions

The behavioral economics of substance use disorders: Reinforcement pathologies and their repair

The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reorcer pathology. Reorcer pathology refers to the joint effects of (a) the persistently high valuation of a reorcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reorcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reorcer pathology, the processes that engender reorcer pathology, and the approaches and procedures that can repair reorcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics. © 2014 by Annual Reviews