|
| Recent Advances in Behavioral Economics and Delay Discounting |
| Sunday, May 27, 2007 |
| 1:30 PM–2:50 PM |
| Randle A |
| Area: EAB; Domain: Basic Research |
| Chair: Chad M. Galuska (University of Michigan) |
| Abstract: This symposium will highlight recent advances in, and relations between, the research areas of behavioral economics and delay discounting. In the first presentation, Madden and colleagues will integrate behavioral economics with delay discounting in describing an animal model of gambling. Differences in gambling between high- and low-impulsive rats will be examined. In the second presentation, Myerson and colleagues will examine how future gains and losses are discounted; specifically, they will argue that hyperboloid discounting, and not differences in discounting rates associated with reinforcer magnitude, determine the preference reversals often observed in choice between delayed outcomes. In the third presentation, Yankelevitz and colleagues will describe their recent work on token economies in both pigeons and people. Token earning will be dissociated from token utilization, and Yankelevitz will describe how both species adopt an earning-utilization strategy that minimizes the overall unit price of the commodity. Finally, Galuska and colleagues will assess rhesus monkeys’ demand for a number of drugs of abuse. Galuska will describe the strengths and weaknesses of a novel procedure designed to generate drug demand functions within a single session. Together, these presentations demonstrate the usefulness of behavioral economic and discounting procedures in shedding light on the determinants of complex and socially relevant behaviors. |
| |
| Behavioral Economics, Impulsivity, and Empirical Findings From an Animal Model of Gambling. |
| GREGORY J. MADDEN (University of Kansas), Patrick S. Johnson (University of Kansas), Nathaniel G. Smith (University of Kansas), Adam T. Brewer (University of Kansas) |
| Abstract: Mazur's (1987) hyperbolic discounting function predicts that high-impulsive individuals will prefer reinforcers obtained from gambling-like schedules of reinforcement more than will low-impulsive individuals. This prediction was tested using Wistar rats characterized as either high- or low-impulsive based on a choice assay. The animal model pits gambling-like RR schedules against FR schedules. Choosing to gamble results in reduced income because the price of the RR reinforcer exceeds that of the FR reinforcer and rats were given a fixed response income. Impulsivity selections have been completed and the gambling assay is underway. |
| |
| Preference Reversals with Losses. |
| JOEL MYERSON (Washington University), Leonard Green (Washington University), Daniel D. Holt (University of Wisconsin, Eau Claire), Sara J. Estle (University of Wisconsin, Eau Claire) |
| Abstract: People who choose a larger, later gain over a smaller, sooner gain when considering outcomes far in the future will often reverse their preference as these alternatives become closer in time. This finding, which is contrary to a normative economic account of intertemporal choice, is predicted by the hyperboloid discounting of delayed gains. The present study demonstrates that an analogous phenomenon occurs with delayed losses. Because larger and smaller losses were discounted at equivalent rates, in contrast to the magnitude effect found with delayed gains, the present findings provide strong support for the idea that preference reversals in choice between delayed outcomes occur because of the hyperboloid shape of the discount function rather than because of a magnitude effect. |
| |
| Reinforcer Accumulation: A Cross-Species Analysis. |
| RACHELLE L. YANKELEVITZ (University of Florida), Timothy D. Hackenberg (University of Florida), Christopher E. Bullock (University of Florida) |
| Abstract: Both pigeons’ and humans’ decisions about how much of a commodity to earn before utilizing it are influenced by the amount of work associated with earning and utilizing. In the present study, pigeons’ and humans’ responses on the left (token-production) key resulted in presentation of a token in the form of a stimulus light according to a fixed-ratio (FR) schedule. After one token was earned, the right (exchange-production) key became available. Thus, subjects could choose to accumulate multiple tokens before exchanging them for another reinforcer (mixed grain for pigeons, 30 s video clips for humans) or to exchange immediately after tokens were earned. The FR requirements on the token-production and exchange-production keys varied systematically across conditions. Pigeons accumulated tokens with greater frequency and magnitude at higher token-production and exchange-production ratios, and choices conformed more to minimization of unit price (responses per reinforcer) when deviations from minimization were most costly. Humans minimized unit price under nearly all ratio combinations. In a subsequent experiment, humans accumulated fewer tokens and less often when a probabilistic token-loss contingency was imposed on earning certain tokens. The results show that accumulation by both pigeons and humans is a function of token-production and exchange-production work requirements. |
| |
| A New Procedure to Rapidly Assess Drug Demand in Rhesus Monkeys. |
| CHAD M. GALUSKA (University of Michigan), Gail Winger (University of Michigan), Steven R. Hursh (Institutes for Behavior Resources, Inc. and Johns Hopkins University School of Medicine), James H. Woods (University of Michigan) |
| Abstract: The rate at which drug consumption decreases with increases in price is referred to as elasticity and may correspond to abuse potential. In our laboratory, rhesus monkeys self-administer drugs (via an intravenous catheter) by lever-pressing. In our traditional procedure, the price of the drug is held constant within a session and manipulated across sessions. The purpose of this study was to generate a demand function within a single session. Sessions were divided into five 30-minute components. The fixed-ratio requirement to produce a drug injection increased across components (10, 32, 100, 320, and 1000). Different doses of cocaine, methohexital, remifentanil, fentanyl, ethanol, and the non-drug reinforcer aspartame were investigated. With few exceptions the rank-order of drugs in terms of elasticity was similar using both the traditional and within-session procedures. Within-session demand functions obtained with the ultra-short acting remifentanil were similar to those obtained traditionally. When larger doses and longer-acting compounds were investigated, however, within-session demand functions were more elastic than those obtained traditionally. These results suggest that drug accumulation across components may affect demand, limiting the usefulness of the within-session procedure. Despite this limitation, this rapid demand assessment procedure may prove useful in investigating how drug demand changes on a daily basis during addiction, physical dependence, and withdrawal. |
|
| |