Association for Behavior Analysis International

The Association for Behavior Analysis International® (ABAI) is a nonprofit membership organization with the mission to contribute to the well-being of society by developing, enhancing, and supporting the growth and vitality of the science of behavior analysis through research, education, and practice.


35th Annual Convention; Phoenix, AZ; 2009

Event Details

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Symposium #241
Recent research on delay discounting and timing
Sunday, May 24, 2009
1:30 PM–2:50 PM
North 225
Area: EAB; Domain: Experimental Analysis
Chair: Ana A. Baumann (Washington University)
Abstract: The goal of this symposium is to highlight recent work in delay discounting, an index of impulsive choice, in probability discounting, an index of risk taking, and on time perception. In the first presentation, Mitchell will present data on the relation between delay discounting, probability discounting and effort discounting in rats. Reynolds will next discuss delay discounting by adolescent smokers and non-smokers and the relation between discounting of delayed outcomes and stress. For the third talk, Baumann and Odum will examine relations among delay discounting, probability discounting, time perception and time perspective of undergraduate students. Finally, McClure and colleagues will discuss methodological and theoretical issues of timing studies.
Implications of the tenuous relationship between delay, probability and effort discounting in rats
SUZANNE H. MITCHELL (Oregon Health & Science Univ)
Abstract: Understanding the relationship between discounting the value of rewards according to different costs (delay, probability, effort) will provide information about the mechanisms used to combine costs to create “unit prices”, which strongly affect choice behavior, response rates and persistence. Rats (N = 30) chose between a small amount of sucrose available immediately, for certain, with a minimal level of effort and a larger amount available (1) following a delay [Delay chamber], (2) probabilistically [Probability chamber], (3) after fulfilling an effort requirement [Effort chamber]. Rats completed 5 consecutive sessions in each chamber, allowing them to complete a series of delay/probability/effort requirements, before cycling to the next chamber until 25 sessions had been completed in each chamber. Hyperbolic equations were fit to quantify the gradient of the delay, probability and effort discounting functions. The equations fit the data well but the gradients for the different types of discounting were not well correlated. That is, individuals that discounted delayed rewards steeply did not discount effortful or probabilistic rewards steeply. This implies that individual differences in response to delayed rewards do not predict individual differences in response to other cost metrics, and that common cost currencies are weighted functions
Delay discounting and self reported stress in adolescent smokers and nonsmokers
BRADY A. REYNOLDS (Research Institute at Nationwide Children’s Hospital)
Abstract: Delay Discounting (DD) is an index of impulsive choice, and research has shown that adolescent daily smokers discount more by delay than adolescent nonsmokers (Reynolds et al., 2007). However, little research has explored associations between DD and other known risk factors for cigarette smoking during adolescence. The current study compared DD and ratings of stress (Perceived Stress Scale, PSS) in two demographically matched groups of adolescents: daily smokers (n = 50) and nonsmokers (n = 50). Daily smokers had significantly higher cotinine levels (metabolite of nicotine) than nonsmokers, thus verifying cigarette smoking status. The daily smokers discounted significantly more by delay than the nonsmokers [p < .01]. Similarly, smokers reported greater levels of stress than nonsmokers [p < .01]. Also, DD and PSS ratings were significantly correlated [r = -.269, p < .01], with higher levels of stress associated with more discounting by delay. Using a binary logistic regression, DD and PSS ratings were determined to be significant, independent predictors of adolescent smoking status. These findings generally indicate there is an association between DD and self reported stress in adolescent smokers and nonsmokers. However, when considered together, DD and stress ratings were each significant independent predictors of smoking status.
Relationship between impulsivity, risk taking, time perception and time perspective.
ANA A. BAUMANN (Washington University), Amy Odum (Utah State University)
Abstract: The present study aimed to evaluate (a) the extent to which different impulsivity and risk taking measures would be related to each other and (b) the extent to which impulsivity, time perception and time perspective are related to each other. One hundred and forty three participants were exposed to the delay discounting, probability discounting and temporal bisection tasks and answered the Barratt Impulsiveness Scale (BIS-11, Patton, Stanford, & Barratt, 1995) and the Zimbardo Time Perspective Inventory (ZTPI, Zimbardo & Boyd, 1999). Results showed that the Non-Planning subscale, but not the other subscales, was related to the AUC of delay discounting. The AUCs for delay and probability discounting were positively correlated with each other. The outcomes of the temporal bisection procedure, as well as the scores on the ZTPI were correlated with the AUCs for delay discounting, and the scores on the ZTPI were correlated with the scores on the BIS, suggesting that time perception and time perspective are related to impulsivity. Interestingly, scores on the ZTPI were correlated in a similar way to probability discounting, suggesting that risk taking can also be affected by time perspective.
The use of diverse disruptors to inform methodological and theoretical concerns of timing
ERIN A. MCCLURE (University of Florida), Kathryn A. Saulsgiver (University of Florida), Clive D. L. Wynne (University of Florida)
Abstract: When determining how animals come to time intervals in the seconds to minutes range, a variety of disruptors have been used to provide insight into the controlling mechanisms of this adaptive behavior. The problems in this endeavor have proved to be methodological and theoretical. The most common drugs used in the study of timing in non-human animals have been compounds that affect dopamine systems in the brain, which are implicated in neurologically-based accounts of timing behavior. Recent results from our laboratory have failed to support many of the theories of timing currently popular in the literature. The current study uses various pharmacological agents (d-amphetamine, haloperidol, and nicotine), as well as non-pharmacological disruptors (pre-session feeding and extinction), to provide evidence for a unified theory of timing that accounts for a diverse array of disruptors. The current study also assesses procedural differences in the timing literature that have been largely overlooked, but could potentially play a role in differential results and interpretations. Only when methodological and theoretical issues in the timing literature are reconciled will we be able to contribute to the understanding of the role that temporal discrimination plays in delay discounting.



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