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Sample records for delayed reward discounting

  1. Delayed discounting of pain with and without monetary reward

    Directory of Open Access Journals (Sweden)

    Kicman Paweł

    2017-12-01

    Full Text Available We investigated the effect of monetary rewards on the rate of pain discounting. Our aim, also, was to understand the effect of previous painful dental experiences on the rate of discounting pain. Two groups (N = 148 completed a discounting task. In the first group, delayed pain was weaker than immediate pain, and in the second group delayed pain was stronger than immediate pain. Two conditions were studied: pain was either accompanied by a monetary reward or not. We found that people preferred immediate pain when it was weaker than delayed pain; however, when delayed pain was stronger than immediate pain, there was no clear preference. In both groups the preference for immediate pain was higher when pain was accompanied by a monetary reward. Previous painful experiences were not related to the rate of discounting. It was concluded that the preference for delayed pain depends on the intensity of pain, and it can be modified by rewards that accompany pain.

  2. Sleep deprivation alters effort discounting but not delay discounting of monetary rewards.

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    Libedinsky, Camilo; Massar, Stijn A A; Ling, Aiqing; Chee, Weiyan; Huettel, Scott A; Chee, Michael W L

    2013-06-01

    To determine whether sleep deprivation would affect the discounting of delayed rewards, of rewards entailing the expense of effort, or both. We measured rates of two types of reward discounting under conditions of rested wakefulness (RW) and sleep deprivation (SD). Delay discounting was defined as the willingness to accept smaller monetary rewards sooner rather than larger monetary rewards later. Effort discounting was defined as the willingness to accept smaller rewards that require less effort to obtain (e.g., typing a small number of letter strings backward) over larger but more effortful rewards (e.g., typing more letter strings to receive the reward). The first two experiments used a crossover design in which one session was conducted after a normal night of sleep (RW), and the other after a night without sleep (SD). The first experiment evaluated only temporal discounting whereas the second evaluated temporal and effort discounting. In the second experiment, the discounting tasks were repeatedly administered prior to the state comparisons to minimize the effects of order and/or repeated testing. In a third experiment, participants were studied only once in a between-subject evaluation of discounting across states. The study took place in a research laboratory. Seventy-seven healthy young adult participants: 20 in Experiment 1, 27 in Experiment 2, and 30 in Experiment 3. N/A. Sleep deprivation elicited increased effort discounting but did not affect delay discounting. The dissociable effects of sleep deprivation on two forms of discounting behavior suggest that they may have differing underlying neural mechanisms.

  3. Delay discounting of oral morphine and sweetened juice rewards in dependent and non-dependent rats.

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    Harvey-Lewis, Colin; Perdrizet, Johnna; Franklin, Keith B J

    2014-07-01

    Opioid-dependent humans are reported to show accelerated delay discounting of opioid rewards when compared to monetary rewards. It has been suggested that this may reflect a difference in discounting of consumable and non-consumable goods not specific to dependent individuals. Here, we evaluate the discounting of similar morphine and non-morphine oral rewards in dependent and non-dependent rats We first tested the analgesic and rewarding effects of our morphine solution. In a second experiment, we assigned rats randomly to either dependent or non-dependent groups that, 30 min after daily testing, received 30 mg/kg subcutaneous dose of morphine, or saline, respectively. Delay discounting of drug-free reward was examined prior to initiation of the dosing regimen. We tested discounting of the morphine reward in half the rats and retested the discounting of the drug-free reward in the other half. All tests were run 22.5 h after the daily maintenance dose. Rats preferred the morphine cocktail to the drug-free solution and consumed enough to induce significant analgesia. The control quinine solution did not produce these effects. Dependent rats discounted morphine rewards more rapidly than before dependence and when compared to discounting drug-free rewards. In non-dependent rats both reward types were discounted similarly. These results show that morphine dependence increases impulsiveness specifically towards a drug reward while morphine experience without dependence does not.

  4. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting.

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    Negash, Sesen; Sheppard, Nicole Van Ness; Lambert, Nathaniel M; Fincham, Frank D

    2016-01-01

    Internet pornography is a multi-billion-dollar industry that has grown increasingly accessible. Delay discounting involves devaluing larger, later rewards in favor of smaller, more immediate rewards. The constant novelty and primacy of sexual stimuli as particularly strong natural rewards make Internet pornography a unique activator of the brain's reward system, thereby having implications for decision-making processes. Based on theoretical studies of evolutionary psychology and neuroeconomics, two studies tested the hypothesis that consuming Internet pornography would relate to higher rates of delay discounting. Study 1 used a longitudinal design. Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2 tested for causality with an experimental design. Participants were randomly assigned to abstain from either their favorite food or pornography for three weeks. Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. Theoretical and clinical implications of these studies are highlighted.

  5. OPPORTUNITY COSTS OF REWARD DELAYS AND THE DISCOUNTING OF HYPOTHETICAL MONEY AND CIGARETTES

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    Johnson, Patrick S.; Herrmann, Evan S.; Johnson, Matthew W.

    2015-01-01

    Humans are reported to discount delayed rewards at lower rates than nonhumans. However, nonhumans are studied in tasks that restrict reinforcement during delays, whereas humans are typically studied in tasks that do not restrict reinforcement during delays. In nonhuman tasks, the opportunity cost of restricted reinforcement during delays may increase delay discounting rates. The present within-subjects study used online crowdsourcing (Amazon Mechanical Turk, or MTurk) to assess the discounting of hypothetical delayed money (and cigarettes in smokers) under four hypothetical framing conditions differing in the availability of reinforcement during delays. At one extreme, participants were free to leave their computer without returning, and engage in any behavior during reward delays (modeling typical human tasks). At the opposite extreme, participants were required to stay at their computer and engage in little other behavior during reward delays (modeling typical nonhuman tasks). Discounting rates increased as an orderly function of opportunity cost. Results also indicated predominantly hyperbolic discounting, the “magnitude effect,” steeper discounting of cigarettes than money, and positive correlations between discounting rates of these commodities. This is the first study to test the effects of opportunity costs on discounting, and suggests that procedural differences may partially account for observed species differences in discounting. PMID:25388973

  6. Heroin addicts have higher discount rates for delayed rewards than non-drug-using controls.

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    Kirby, K N; Petry, N M; Bickel, W K

    1999-03-01

    Fifty-six heroin addicts and 60 age-matched controls were offered choices between monetary rewards ($11-$80) available immediately and larger rewards ($25-$85) available after delays ranging from 1 week to 6 months. Participants had a 1-in-6 chance of winning a reward that they chose on one randomly selected trial. Delay-discounting rates were estimated from the pattern of participants' choices. The discounting model of impulsiveness (Ainslie, 1975) implies that delay-discounting rates are positively correlated with impulsiveness. On average, heroin addicts' discount rates were twice those of controls (p = .004), and discount rates were positively correlated with impulsivity as measured by self-report questionnaires (p discounting rate as a measure of impulsiveness, a characteristic associated with substance abuse.

  7. Exchanging the liquidity hypothesis: Delay discounting of money and self-relevant non-money rewards.

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    Stuppy-Sullivan, Allison M; Tormohlen, Kayla N; Yi, Richard

    2016-01-01

    Evidence that primary rewards (e.g., food and drugs of abuse) are discounted more than money is frequently attributed to money's high degree of liquidity, or exchangeability for many commodities. The present study provides some evidence against this liquidity hypothesis by contrasting delay discounting of monetary rewards (liquid) and non-monetary commodities (non-liquid) that are self-relevant and utility-matched. Ninety-seven (97) undergraduate students initially completed a conventional binary-choice delay discounting of money task. Participants returned one week later and completed a self-relevant commodity delay discounting task. Both conventional hypothesis testing and more-conservative tests of statistical equivalence revealed correspondence in rate of delay discounting of money and self-relevant commodities, and in one magnitude condition, less discounting for the latter. The present results indicate that liquidity of money cannot fully account for the lower rate of delay discounting compared to non-money rewards. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Steeper discounting of delayed rewards in schizophrenia but not first-degree relatives.

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    Yu, Linda Q; Lee, Sangil; Katchmar, Natalie; Satterthwaite, Theodore D; Kable, Joseph W; Wolf, Daniel H

    2017-06-01

    Excessive discounting of future rewards has been related to a variety of risky behaviors and adverse clinical conditions. Prior work examining delay discounting in schizophrenia suggests an elevated discount rate. However, it remains uncertain whether this reflects the disease process itself or an underlying genetic vulnerability, whether it is selective for delay discounting or reflects pervasive changes in decision-making, and whether it is driven by specific clinical dimensions such as cognitive impairment. Here we investigated delay discounting, as well as loss aversion and risk aversion, in three groups: schizophrenia (SZ), unaffected first-degree family members (FM), and controls without a family history of psychosis (NC). SZ had elevated discounting, without changes in loss aversion or risk aversion. Contrary to expectations, the FM group did not show an intermediate phenotype in discounting. Higher discount rates correlated with lower cognitive performance on verbal reasoning, but this did not explain elevated discount rates in SZ. Group differences were driven primarily by the non-smoking majority of the sample. This study provides further evidence for elevated discounting in schizophrenia, and demonstrates that steeper discounting is not necessarily associated with familial risk, cannot be wholly accounted for by cognitive deficits, and is not attributable to smoking-related impulsivity. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  9. Discounting of Monetary Rewards that are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, not Additively

    Science.gov (United States)

    Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

    2014-01-01

    The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects of reward amount. Previous research has focused on the discounting of delayed and probabilistic rewards separately, with little research examining more complex situations in which rewards are both delayed and probabilistic. In two experiments, participants made choices between smaller rewards that were both immediate and certain and larger rewards that were both delayed and probabilistic. Analyses revealed significant interactions between delay and probability factors inconsistent with an additive model. In contrast, a hyperboloid discounting model in which delay and probability were combined multiplicatively provided an excellent fit to the data. These results suggest that the hyperboloid is a good descriptor of decision making in complicated monetary choice situations like those people encounter in everyday life. PMID:24933696

  10. Concave utility, transaction costs, and risk in measuring discounting of delayed rewards.

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    Kirby, Kris N; Santiesteban, Mariana

    2003-01-01

    Research has consistently found that the decline in the present values of delayed rewards as delay increases is better fit by hyperbolic than by exponential delay-discounting functions. However, concave utility, transaction costs, and risk each could produce hyperbolic-looking data, even when the underlying discounting function is exponential. In Experiments 1 (N = 45) and 2 (N = 103), participants placed bids indicating their present values of real future monetary rewards in computer-based 2nd-price auctions. Both experiments suggest that utility is not sufficiently concave to account for the superior fit of hyperbolic functions. Experiment 2 provided no evidence that the effects of transaction costs and risk are large enough to account for the superior fit of hyperbolic functions.

  11. Inhibiting food reward: delay discounting, food reward sensitivity, and palatable food intake in overweight and obese women.

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    Appelhans, Bradley M; Woolf, Kathleen; Pagoto, Sherry L; Schneider, Kristin L; Whited, Matthew C; Liebman, Rebecca

    2011-11-01

    Overeating is believed to result when the appetitive motivation to consume palatable food exceeds an individual's capacity for inhibitory control of eating. This hypothesis was supported in recent studies involving predominantly normal weight women, but has not been tested in obese populations. The current study tested the interaction between food reward sensitivity and inhibitory control in predicting palatable food intake among energy-replete overweight and obese women (N = 62). Sensitivity to palatable food reward was measured with the Power of Food Scale. Inhibitory control was assessed with a computerized choice task that captures the tendency to discount large delayed rewards relative to smaller immediate rewards. Participants completed an eating in the absence of hunger protocol in which homeostatic energy needs were eliminated with a bland preload of plain oatmeal, followed by a bogus laboratory taste test of palatable and bland snacks. The interaction between food reward sensitivity and inhibitory control was a significant predictor of palatable food intake in regression analyses controlling for BMI and the amount of preload consumed. Probing this interaction indicated that higher food reward sensitivity predicted greater palatable food intake at low levels of inhibitory control, but was not associated with intake at high levels of inhibitory control. As expected, no associations were found in a similar regression analysis predicting intake of bland foods. Findings support a neurobehavioral model of eating behavior in which sensitivity to palatable food reward drives overeating only when accompanied by insufficient inhibitory control. Strengthening inhibitory control could enhance weight management programs.

  12. Discounting of Delayed Food Rewards in Pigeons and Rats: Is There a Magnitude Effect

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    Green, Leonard; Myerson, Joel; Holt, Daniel D.; Slavin, John R.; Estle, Sara J.

    2004-01-01

    Temporal discounting refers to the decrease in the present, subjective value of a reward as the time to its receipt increases. Results from humans have shown that a hyperbola-like function describes the form of the discounting function when choices involve hypothetical monetary rewards. In addition, magnitude effects have been reported in which…

  13. Heroin and cocaine abusers have higher discount rates for delayed rewards than alcoholics or non-drug-using controls.

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    Kirby, Kris N; Petry, Nancy M

    2004-04-01

    To test a prediction of the discounting model of impulsiveness that discount rates would be positively associated with addiction. The delay-discount rate refers to the rate of reduction in the present value of a future reward as the delay to that reward increases. We estimated participants' discount rates on the basis of their pattern of choices between smaller immediate rewards ($11-80) and larger, delayed rewards ($25-85; at delays from 1 week to 6 months) in a questionnaire format. Participants had a one-in-six chance of winning a reward that they chose on one randomly selected trial. Heroin (n = 27), cocaine (n = 41) and alcohol (n = 33) abusers and non-drug-using controls (n = 44) were recruited from advertisements. They were tested in a drug abuse research clinic at a medical school. On average, the cocaine and heroin groups had higher rates than controls (both P rates for heroin abusers (P = 0.03), but not for cocaine or alcohol abusers (both P > 0.50). These data suggest that discount rates vary with the preferred drug of abuse, and that high discount rates should be considered in the development of substance abuse prevention and treatment efforts.

  14. Discounting of Monetary Rewards That Are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, Not Additively

    Science.gov (United States)

    Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

    2015-01-01

    The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects…

  15. Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis.

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    Amlung, M; Petker, T; Jackson, J; Balodis, I; MacKillop, J

    2016-08-01

    An increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case-control comparisons and continuous designs; (2) to examine potential moderators, including case-control v. continuous design, money v. food rewards, sample sex distribution, and sample age (18 years); and (3) to evaluate publication bias. From 134 candidate articles, 39 independent investigations yielded 29 case-control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies. The primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg-Mazumdar test and meta-regression suggested a slightly diminishing effect size over time. Steep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

  16. Statistical equivalence and test-retest reliability of delay and probability discounting using real and hypothetical rewards.

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    Matusiewicz, Alexis K; Carter, Anne E; Landes, Reid D; Yi, Richard

    2013-11-01

    Delay discounting (DD) and probability discounting (PD) refer to the reduction in the subjective value of outcomes as a function of delay and uncertainty, respectively. Elevated measures of discounting are associated with a variety of maladaptive behaviors, and confidence in the validity of these measures is imperative. The present research examined (1) the statistical equivalence of discounting measures when rewards were hypothetical or real, and (2) their 1-week reliability. While previous research has partially explored these issues using the low threshold of nonsignificant difference, the present study fully addressed this issue using the more-compelling threshold of statistical equivalence. DD and PD measures were collected from 28 healthy adults using real and hypothetical $50 rewards during each of two experimental sessions, one week apart. Analyses using area-under-the-curve measures revealed a general pattern of statistical equivalence, indicating equivalence of real/hypothetical conditions as well as 1-week reliability. Exceptions are identified and discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Positive mood effects on delay discounting.

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    Hirsh, Jacob B; Guindon, Alex; Morisano, Dominique; Peterson, Jordan B

    2010-10-01

    Delay discounting is the process by which the value of an expected reward decreases as the delay to obtaining that reward increases. Individuals with higher discounting rates tend to prefer smaller immediate rewards over larger delayed rewards. Previous research has indicated that personality can influence an individual's discounting rates, with higher levels of Extraversion predicting a preference for immediate gratification. The current study examined how this relationship would be influenced by situational mood inductions. While main effects were observed for both Extraversion and cognitive ability in the prediction of discounting rates, a significant interaction was also observed between Extraversion and positive affect. Extraverted individuals were more likely to prefer an immediate reward when first put in a positive mood. Extraverts thus appear particularly sensitive to impulsive, incentive-reward-driven behavior by temperament and by situational factors heightening positive affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  18. Impulsive Delayed Reward Discounting as a Genetically-Influenced Target for Drug Abuse Prevention: A Critical Evaluation

    Directory of Open Access Journals (Sweden)

    Joshua C. Gray

    2015-09-01

    Full Text Available This review evaluates the viability of delayed reward discounting (DRD, an index of how much an individual devalues a future reward based on its delay in time, for genetically-informed drug abuse prevention. A review of the literature suggests that impulsive DRD is robustly associated with drug addiction and meets most of the criteria for being an endophenotype, albeit with mixed findings for specific molecular genetic influences. Several modes of experimental manipulation have been demonstrated to reduce DRD acutely. These include behavioral strategies, such as mindfulness, reward bundling, and episodic future thinking; pharmacological interventions, including noradrengic agonists, adrenergic agonists, and multiple monoamine agonists; and neuromodulatory interventions, such as transcranial magnetic stimulation and transcranial direct current stimulation. However, the generalization of these interventions to positive clinical outcomes remains unclear and no studies to date have examined interventions on DRD in the context of prevention. Collectively, these findings suggest it would be premature to target DRD for genetically-informed prevention. Indeed, given the evidence of environmental contributions such as early life adversity to impulsive DRD, whether genetically-informed secondary prevention would ever be warranted is debatable. However, progress in identifying polymorphisms associated with DRD preference could further clarify the underlying biological systems implicated in impulsive DRD for further progress in pharmacological and neuromodulatory interventions. Furthermore, independent of genetically-informed prevention, impulsive DRD is a qualitatively different risk factor from existing prevention programs and is generally worthy of investigation as a novel and promising drug abuse prevention target.

  19. Drinking status but not acute alcohol consumption influences delay discounting.

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    Adams, Sally; Attwood, Angela S; Munafò, Marcus R

    2017-09-01

    The aim of this study was to investigate the following: (a) the effects of acute alcohol on delay discounting; (b) the effects of drinking status on delayed discounting; and (c) whether these effects differ according to reward type (alcohol vs. money). Heavy and light social alcohol users (n = 96) were randomized to receive either an acute dose of alcohol at 0.4 or 0.6 g/kg or placebo in a between-subjects, double-blind design. Delay discounting of alcohol and monetary rewards was measured using a hyperbolic model, with higher scores indicative of greater delay discounting. ANOVA of discount scores indicated a main effect of reward type, where all participants had higher discount scores for alcohol versus money rewards. A main effect of drinking status was also observed, where heavier drinkers had higher discount scores compared with lighter drinkers. We did not observe a main effect of acute alcohol use on delay discounting or the hypothesized interactions between acute alcohol use and drinking status with reward type. Our data suggest that heavier drinkers discount the value of delayed rewards more steeply than lighter drinkers. Delay discounting may therefore be a promising marker of heavy alcohol consumption in social drinkers. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Assessing delay discounting in mice

    OpenAIRE

    Mitchell, Suzanne H.

    2014-01-01

    Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

  1. A 5-trial adjusting delay discounting task: Accurate discount rates in less than 60 seconds

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    Koffarnus, Mikhail N.; Bickel, Warren K.

    2014-01-01

    Individuals who discount delayed rewards at a high rate are more likely to engage in substance abuse, overeating, or problem gambling. Findings such as these suggest the value of methods to obtain an accurate and fast measurement of discount rate that can be easily deployed in variety of settings. In the present study, we developed and evaluated the 5-trial adjusting delay task, a novel method of obtaining discount rate in less than one minute. We hypothesized that discount rates from the 5-trial adjusting delay task would be similar and correlated with discount rates from a lengthier task we have used previously, and that four known effects relating to delay discounting would be replicable with this novel task. To test these hypotheses, the 5-trial adjusting delay task was administered to 111 college students six times to obtain discount rates for six different commodities, along with a lengthier adjusting amount discounting task. We found that discount rates were similar and correlated between the 5-trial adjusting delay task and the adjusting amount task. Each of the four known effects relating to delay discounting was replicated with the 5-trial adjusting delay task to varying degrees. First, discount rates were inversely correlated with amount. Second, discount rates between past and future outcomes were correlated. Third, discount rates were greater for consumable rewards than with money, although we did not control for amount in this comparison. Fourth, discount rates were lower when zero amounts opposing the chosen time point were explicitly described. Results indicate that the 5-trial adjusting delay task is a viable, rapid method to assess discount rate. PMID:24708144

  2. A 5-trial adjusting delay discounting task: accurate discount rates in less than one minute.

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    Koffarnus, Mikhail N; Bickel, Warren K

    2014-06-01

    Individuals who discount delayed rewards at a high rate are more likely to engage in substance abuse, overeating, or problem gambling. Such findings suggest the value of methods to obtain an accurate and fast measurement of discount rate that can be easily deployed in variety of settings. In the present study, we developed and evaluated the 5-trial adjusting delay task, a novel method of obtaining a discount rate in less than 1 min. We hypothesized that discount rates from the 5-trial adjusting delay task would be similar and would correlate with discount rates from a lengthier task we have used previously, and that 4 known effects relating to delay discounting would be replicable with this novel task. To test these hypotheses, the 5-trial adjusting delay task was administered to 111 college students 6 times to obtain discount rates for 6 different commodities, along with a lengthier adjusting amount discounting task. We found that discount rates were similar and correlated between the 5-trial adjusting delay task and the adjusting amount task. Each of the 4 known effects relating to delay discounting was replicated with the 5-trial adjusting delay task to varying degrees. First, discount rates were inversely correlated with amount. Second, discount rates between past and future outcomes were correlated. Third, discount rates were greater for consumable rewards than with money, although we did not control for amount in this comparison. Fourth, discount rates were lower when $0 amounts opposing the chosen time point were explicitly described. Results indicate that the 5-trial adjusting delay task is a viable, rapid method to assess discount rate. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  3. Delay Discounting: Pigeon, Rat, Human – Does it Matter?

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    Vanderveldt, Ariana; Oliveira, Luís; Green, Leonard

    2016-01-01

    Delay discounting refers to the decrease in subjective value of an outcome as the time to its receipt increases. Across species and situations, animals discount delayed rewards, and their discounting is well-described by a hyperboloid function. The current review begins with a comparison of discounting models and the procedures used to assess delay discounting in nonhuman animals. We next discuss the generality of discounting, reviewing the effects of different variables on the degree of discounting delayed reinforcers by nonhuman animals. Despite the many similarities in discounting observed between human and nonhuman animals, several differences have been proposed (e.g., the magnitude effect; nonhuman animals discount over a matter of seconds whereas humans report willing to wait months, if not years before receiving a reward), raising the possibility of fundamental species differences in intertemporal choice. After evaluating these differences, we discuss delay discounting from an adaptationist perspective. The pervasiveness of discounting across species and situations suggests it is a fundamental process underlying decision making. PMID:26881899

  4. Hippocampus, delay discounting, and vicarious trial-and-error.

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    Bett, David; Murdoch, Lauren H; Wood, Emma R; Dudchenko, Paul A

    2015-05-01

    In decision-making, an immediate reward is usually preferred to a delayed reward, even if the latter is larger. We tested whether the hippocampus is necessary for this form of temporal discounting, and for vicarious trial-and-error at the decision point. Rats were trained on a recently developed, adjustable delay-discounting task (Papale et al. (2012) Cogn Affect Behav Neurosci 12:513-526), which featured a choice between a small, nearly immediate reward, and a larger, delayed reward. Rats then received either hippocampus or sham lesions. Animals with hippocampus lesions adjusted the delay for the larger reward to a level similar to that of sham-lesioned animals, suggesting a similar valuation capacity. However, the hippocampus lesion group spent significantly longer investigating the small and large rewards in the first part of the sessions, and were less sensitive to changes in the amount of reward in the large reward maze arm. Both sham- and hippocampus-lesioned rats showed a greater amount of vicarious trial-and-error on trials in which the delay was adjusted. In a nonadjusting version of the delay discounting task, animals with hippocampus lesions showed more variability in their preference for a larger reward that was delayed by 10 s compared with sham-lesioned animals. To verify the lesion behaviorally, rat were subsequently trained on a water maze task, and rats with hippocampus lesions were significantly impaired compared with sham-lesioned animals. The findings on the delay discounting tasks suggest that damage to the hippocampus may impair the detection of reward magnitude. © 2014 Wiley Periodicals, Inc.

  5. The Vivid Present: Visualization Abilities Are Associated with Steep Discounting of Future Rewards.

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    Parthasarathi, Trishala; McConnell, Mairead H; Luery, Jeffrey; Kable, Joseph W

    2017-01-01

    Humans and other animals discount the value of future rewards, a phenomenon known as delay discounting. Individuals vary widely in the extent to which they discount future rewards, and these tendencies have been associated with important life outcomes. Recent studies have demonstrated that imagining the future reduces subsequent discounting behavior, but no research to date has examined whether a similar principle applies at the trait level, and whether training visualization changes discounting. The current study examined if individual differences in visualization abilities are linked to individual differences in discounting and whether practicing visualization can change discounting behaviors in a lasting way. Participants ( n = 48) completed the Vividness of Visual Imagery Questionnaire (VVIQ) and delay discounting task and then underwent a 4-week intervention consisting of visualization training (intervention) or relaxation training (control). Contrary to our hypotheses, participants who reported greater visualization abilities (lower scores) on the VVIQ were higher discounters. To further examine this relationship, an additional 106 participants completed the VVIQ and delay discounting task. In the total sample ( n = 154), there was a significant negative correlation between VVIQ scores and discount rates, showing that individuals who are better visualizers are also higher discounters. Consistent with this relationship but again to our surprise, visualization training tended, albeit weakly, to increase discount rates, and those whose VVIQ decreased the most were those whose discount rates increased the most. These results suggest a novel association between visualization abilities and delay discounting.

  6. Brain Structure Linking Delay Discounting and Academic Performance.

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    Wang, Song; Kong, Feng; Zhou, Ming; Chen, Taolin; Yang, Xun; Chen, Guangxiang; Gong, Qiyong

    2017-08-01

    As a component of self-discipline, delay discounting refers to the ability to wait longer for preferred rewards and plays a pivotal role in shaping students' academic performance. However, the neural basis of the association between delay discounting and academic performance remains largely unknown. Here, we examined the neuroanatomical substrates underlying delay discounting and academic performance in 214 adolescents via voxel-based morphometry (VBM) by performing structural magnetic resonance imaging (S-MRI). Behaviorally, we confirmed the significant correlation between delay discounting and academic performance. Neurally, whole-brain regression analyses indicated that regional gray matter volume (rGMV) of the left dorsolateral prefrontal cortex (DLPFC) was associated with both delay discounting and academic performance. Furthermore, delay discounting partly accounted for the association between academic performance and brain structure. Differences in the rGMV of the left DLPFC related to academic performance explained over one-third of the impact of delay discounting on academic performance. Overall, these results provide the first evidence for the common neural basis linking delay discounting and academic performance. Hum Brain Mapp 38:3917-3926, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Cocaine dependent individuals discount future rewards more than future losses for both cocaine and monetary outcomes.

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    Johnson, Matthew W; Bruner, Natalie R; Johnson, Patrick S

    2015-01-01

    Cocaine dependence and other forms of drug dependence are associated with steeper devaluation of future outcomes (delay discounting). Although studies in this domain have typically assessed choices between monetary gains (e.g., receive less money now versus receive more money after a delay), delay discounting is also applicable to decisions involving losses (e.g., small loss now versus larger delayed loss), with gains typically discounted more than losses (the "sign effect"). It is also known that drugs are discounted more than equivalently valued money. In the context of drug dependence, however, relatively little is known about the discounting of delayed monetary and drug losses and the presence of the sign effect. In this within-subject, laboratory study, delay discounting for gains and losses was assessed for cocaine and money outcomes in cocaine-dependent individuals (n=89). Both cocaine and monetary gains were discounted at significantly greater rates than cocaine and monetary losses, respectively (i.e., the sign effect). Cocaine gains were discounted significantly more than monetary gains, but cocaine and monetary losses were discounted similarly. Results suggest that cocaine is discounted by cocaine-dependent individuals in a systematic manner similar to other rewards. Because the sign effect was shown for both cocaine and money, delayed aversive outcomes may generally have greater impact than delayed rewards in shaping present behavior in this population. Copyright © 2014. Published by Elsevier Ltd.

  8. The neural basis of cultural differences in delay discounting.

    Science.gov (United States)

    Kim, Bokyung; Sung, Young Shin; McClure, Samuel M

    2012-03-05

    People generally prefer to receive rewarding outcomes sooner rather than later. Such preferences result from delay discounting, or the process by which outcomes are devalued for the expected delay until their receipt. We investigated cultural differences in delay discounting by contrasting behaviour and brain activity in separate cohorts of Western (American) and Eastern (Korean) subjects. Consistent with previous reports, we find a dramatic difference in discounting behaviour, with Americans displaying much greater present bias and elevated discount rates. Recent neuroimaging findings suggest that differences in discounting may arise from differential involvement of either brain reward areas or regions in the prefrontal and parietal cortices associated with cognitive control. We find that the ventral striatum is more greatly recruited in Americans relative to Koreans when discounting future rewards, but there is no difference in prefrontal or parietal activity. This suggests that a cultural difference in emotional responsivity underlies the observed behavioural effect. We discuss the implications of this research for strategic interrelations between Easterners and Westerners.

  9. Role of delay-based reward in the spatial cooperation

    Science.gov (United States)

    Wang, Xu-Wen; Nie, Sen; Jiang, Luo-Luo; Wang, Bing-Hong; Chen, Shi-Ming

    2017-01-01

    Strategy selection in games, a typical decision making, usually brings noticeable reward for players which have discounted value if the delay appears. The discounted value is measure: earning sooner with a small reward or later with a delayed larger reward. Here, we investigate effects of delayed rewards on the cooperation in structured population. It is found that delayed reward supports the spreading of cooperation in square lattice, small-world and random networks. In particular, intermediate reward differences between delays impel the highest cooperation level. Interestingly, cooperative individuals with the same delay time steps form clusters to resist the invasion of defects, and cooperative individuals with lowest delay reward survive because they form the largest clusters in the lattice.

  10. Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity.

    Science.gov (United States)

    Eisenstein, Sarah A; Gredysa, Danuta M; Antenor-Dorsey, Jo Ann; Green, Leonard; Arbeláez, Ana Maria; Koller, Jonathan M; Black, Kevin J; Perlmutter, Joel S; Moerlein, Stephen M; Hershey, Tamara

    2015-01-01

    Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30) and non-obese (n = 20; body mass indexmonetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methyl)benperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting). Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting). In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

  11. Parabolic discounting of monetary rewards by physical effort

    NARCIS (Netherlands)

    Hartmann, M.N.; Hager, O.M.; Tobler, P.N.; Kaiser, S.

    2013-01-01

    When humans and other animals make decisions in their natural environments prospective rewards have to be weighed against costs. It is well established that increasing costs lead to devaluation or discounting of reward. While our knowledge about discount functions for time and probability costs is

  12. Individual differences in delay discounting under acute stress: the role of trait perceived stress

    Directory of Open Access Journals (Sweden)

    Karolina M. Lempert

    2012-07-01

    Full Text Available Delay discounting refers to the reduction of the value of a future reward as the delay to that reward increases. The rate at which individuals discount future rewards varies as a function of both individual and contextual differences, and high delay discounting rates have been linked with problematic behaviors, including drug abuse and gambling. The current study investigated the effects of acute anticipatory stress on delay discounting, while considering two important factors: individual perceptions of stress and whether the stressful situation is future-focused or present-focused. Half of the participants experienced acute stress by anticipating giving a videotaped speech. This stress was either future-oriented (speech about future job or present-oriented (speech about physical appearance. They then performed a delay discounting task, in which they chose between smaller, immediate rewards and larger, delayed rewards. Their scores on the Perceived Stress Scale were also collected. The way in which one appraises a stressful situation interacts with acute stress to influence choices; under stressful conditions, delay discounting rate was highest in individuals with low perceived stress and lowest for individuals with high perceived stress. This result might be related to individual variation in reward responsiveness under stress. Furthermore, the time orientation of the task interacted with its stressfulness to affect the individual’s propensity to choose immediate rewards. These findings add to our understanding of the intermediary factors between stress and decision making.

  13. Delay Discounting of Losses in Alcohol Use Disorders and Antisocial Psychopathology: Effects of a Working Memory Load.

    Science.gov (United States)

    Gerst, Kyle R; Gunn, Rachel L; Finn, Peter R

    2017-10-01

    Alcohol use disorders (AUDs) are associated with increased discounting of delayed rewards and reduced executive working memory (eWM) capacity. This association is amplified when comorbid with antisocial psychopathology (AP). Furthermore, recent studies suggest that reduced WM capacity is associated with disinhibited decisions reflected by increased impulsive decision making on the delay discounting of rewards task. While discounting of delayed rewards is well studied, the discounting of delayed losses has received significantly less experimental attention. The current study investigated (i) the rate of discounting of delayed losses in individuals with AUD only (n = 61), AUD with comorbid AP (n = 79) and healthy controls (n = 64); (ii) the relationship between eWM capacity and discounting of delayed losses; and (iii) the effect of a WM load on discounting of delayed losses. Discounting performance was assessed using a computerized discounting of delayed losses task. Results showed that the AUD-only and AUD-AP groups had higher rates of discounting of delayed losses and lower eWM capacity compared to the control groups. Lower individual eWM capacity was associated with increased discounting of delayed losses. However, WM load did not increase discounting rates overall. These results support the hypothesis that greater discounting of delayed losses is associated with AUD and comorbid AP problems and lower individual eWM capacity. Copyright © 2017 by the Research Society on Alcoholism.

  14. Examining weight concern and delay discounting in adolescent females.

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    Thamotharan, Sneha; Lange, Krista; Ramos, Ashley; Fields, Sherecce

    2016-04-01

    Pediatric obesity is a growing public health concern that contributes to high rates of negative long-term physical and mental health outcomes. Research focused on identifying risk for pediatric obesity has linked delay discounting, or an inclination for immediate rewards, as well as weight concern to individuals with greater Body Mass Index (BMI). The current study seeks to fill a void in the literature by examining how these two variables interact to promote higher BMI in female adolescents. Adolescent (n=60) females between the ages of 13-19years (mage=17.45, SD=1.74) of age completed the Eating Disorder Examination Questionnaire (EDE-Q) and the Delay Discounting Questionnaire. A mediation model examined whether delay discounting accounted for the relationship between weight concern and BMI. Results indicate that in the current study weight concern was negatively related to delay discounting and delay discounting was negatively related to BMI. The overall model revealed that a partial mediation occurred [b=1.28, t(60)=4.92, pconcerns contribute to greater BMI. Nevertheless, the results indicate that prevention and interventions should identify females with high levels of both weight concern and impulsivity as an increased risk for experiencing pediatric obesity and long-term negative health outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Leveraging delay discounting for health: Can time delays influence food choice?

    Science.gov (United States)

    Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

    2018-03-15

    Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Impatience and Grades: Delay-Discount Rates Correlate Negatively with College Gpa

    Science.gov (United States)

    Kirby, K.N.; Winston, G.C.; Santiesteban, M.

    2005-01-01

    Because the rewards of academic performance in college are often delayed, the delay-discounting model of impulsiveness (Ainslie (1975) [Ainslie, G. Specious reward: A behavioral theory of impulsiveness and impulse control. Psychological Bulletin, 82 (4), 463-496] predicts that academic performance should tend to decrease as people place less…

  17. Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity.

    Directory of Open Access Journals (Sweden)

    Sarah A Eisenstein

    Full Text Available Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30 and non-obese (n = 20; body mass index<30 adults were assessed for percent body fat with dual-energy X-ray absorptiometry and for β-cell function using disposition index. Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methylbenperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting. Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting. In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding

  18. High temporal discounters overvalue immediate rewards rather than undervalue future rewards: an event-related brain potential study.

    Science.gov (United States)

    Cherniawsky, Avital S; Holroyd, Clay B

    2013-03-01

    Impulsivity is characterized in part by heightened sensitivity to immediate relative to future rewards. Although previous research has suggested that "high discounters" in intertemporal choice tasks tend to prefer immediate over future rewards because they devalue the latter, it remains possible that they instead overvalue immediate rewards. To investigate this question, we recorded the reward positivity, a component of the event-related brain potential (ERP) associated with reward processing, with participants engaged in a task in which they received both immediate and future rewards and nonrewards. The participants also completed a temporal discounting task without ERP recording. We found that immediate but not future rewards elicited the reward positivity. High discounters also produced larger reward positivities to immediate rewards than did low discounters, indicating that high discounters relatively overvalued immediate rewards. These findings suggest that high discounters may be more motivated than low discounters to work for monetary rewards, irrespective of the time of arrival of the incentives.

  19. Survey of time preference, delay discounting models

    Directory of Open Access Journals (Sweden)

    John R. Doyle

    2013-03-01

    Full Text Available The paper surveys over twenty models of delay discounting (also known as temporal discounting, time preference, time discounting, that psychologists and economists have put forward to explain the way people actually trade off time and money. Using little more than the basic algebra of powers and logarithms, I show how the models are derived, what assumptions they are based upon, and how different models relate to each other. Rather than concentrate only on discount functions themselves, I show how discount functions may be manipulated to isolate rate parameters for each model. This approach, consistently applied, helps focus attention on the three main components in any discounting model: subjectively perceived money; subjectively perceived time; and how these elements are combined. We group models by the number of parameters that have to be estimated, which means our exposition follows a trajectory of increasing complexity to the models. However, as the story unfolds it becomes clear that most models fall into a smaller number of families. We also show how new models may be constructed by combining elements of different models. The surveyed models are: Exponential; Hyperbolic; Arithmetic; Hyperboloid (Green and Myerson, Rachlin; Loewenstein and Prelec Generalized Hyperboloid; quasi-Hyperbolic (also known as beta-delta discounting; Benhabib et al's fixed cost; Benhabib et al's Exponential / Hyperbolic / quasi-Hyperbolic; Read's discounting fractions; Roelofsma's exponential time; Scholten and Read's discounting-by-intervals (DBI; Ebert and Prelec's constant sensitivity (CS; Bleichrodt et al.'s constant absolute decreasing impatience (CADI; Bleichrodt et al.'s constant relative decreasing impatience (CRDI; Green, Myerson, and Macaux's hyperboloid over intervals models; Killeen's additive utility; size-sensitive additive utility; Yi, Landes, and Bickel's memory trace models; McClure et al.'s two exponentials; and Scholten and Read's trade

  20. Delay or probability discounting in a model of impulsive behavior: effect of alcohol.

    Science.gov (United States)

    Richards, J B; Zhang, L; Mitchell, S H; de Wit, H

    1999-01-01

    Little is known about the acute effects of drugs of abuse on impulsivity and self-control. In this study, impulsivity was assessed in humans using a computer task that measured delay and probability discounting. Discounting describes how much the value of a reward (or punisher) is decreased when its occurrence is either delayed or uncertain. Twenty-four healthy adult volunteers ingested a moderate dose of ethanol (0.5 or 0.8 g/kg ethanol: n = 12 at each dose) or placebo before completing the discounting task. In the task the participants were given a series of choices between a small, immediate, certain amount of money and $10 that was either delayed (0, 2, 30, 180, or 365 days) or probabilistic (i.e., certainty of receipt was 1.0, .9, .75, .5, or .25). The point at which each individual was indifferent between the smaller immediate or certain reward and the $10 delayed or probabilistic reward was identified using an adjusting-amount procedure. The results indicated that (a) delay and probability discounting were well described by a hyperbolic function; (b) delay and probability discounting were positively correlated within subjects; (c) delay and probability discounting were moderately correlated with personality measures of impulsivity; and (d) alcohol had no effect on discounting. PMID:10220927

  1. A Delay Discounting Model of Psychotherapy Termination

    Science.gov (United States)

    Swift, Joshua K.; Callahan, Jennifer L.

    2009-01-01

    Delay discounting (DD) procedures are emerging as an important new method for psychotherapy researchers. In this paper a framework for conceptualizing existing, seemingly discrepant, research findings on termination is introduced and new directions for research are described. To illustrate the value of a DD framework, the common psychotherapy…

  2. The Effects of Inflation and Interest Rates on Delay Discounting in Human Behavior

    Science.gov (United States)

    Kawashima, Kentaro

    2006-01-01

    Interest and inflation rates may be major determinants of delay discounting, but these variables have not been controlled in past experiments because they depend on macroeconomic conditions. This study uses a computer game-like task to investigate the effects of inflation rates on people's subjective valuation of delayed rewards. During the task,…

  3. The effects of the framing of time on delay discounting.

    Science.gov (United States)

    DeHart, William Brady; Odum, Amy L

    2015-01-01

    We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

  4. Spatial discounting of food and social rewards in guppies (Poecilia reticulata

    Directory of Open Access Journals (Sweden)

    Nelly eMühlhoff

    2011-04-01

    Full Text Available In temporal discounting, animals trade off the time to obtain a reward against the quality of a reward, choosing between a smaller reward available sooner versus a larger reward available later. Similar discounting can apply over space, when animals choose between smaller and closer versus larger and more distant rewards. Most studies of temporal and spatial discounting in nonhuman animals use food as the reward, and it is not established whether animals trade off other preferred stimuli in similar ways. Here, we offered female guppies (Poecilia reticulata a spatial discounting task in which we measured preferences for a larger reward as the distance to it increased relative to a closer but smaller reward. We tested whether the fish discounted reward types differently by offering subjects either food items or same-sex conspecifics as rewards. Before beginning the discounting tasks, we conducted validation tests to ensure that subjects equally valued the food and social stimuli in the quantities provided. In the discounting task, subjects switched their preferences from the larger to the smaller reward as the distance to the larger reward increased (spatial discounting, but the pattern and magnitude of discounting did not differ across the two reward types. These findings indicate that guppies show similar patterns of discounting food and social rewards in a spatial task. In an analysis of travel times, however, the fish swam faster to food rewards than to shoaling partners. This difference in travel times implies that fish temporally discounted social rewards less steeply than food rewards. Thus, reward type influences temporal discounting, suggesting a dissociation between temporal and spatial discounting. Our results illustrate how animals adjust choices and travel times depending on both the type of cost (time, distance and benefits (food, social partners.

  5. Predictive Validity of Delay Discounting Behavior in Adolescence: A Longitudinal Twin Study

    Science.gov (United States)

    Isen, Joshua D.; Sparks, Jordan C.; Iacono, William G.

    2014-01-01

    A standard assumption in the delay discounting literature is that individuals who exhibit steeper discounting of hypothetical rewards also experience greater difficulty deferring gratification to real-world rewards. There is ample cross-sectional evidence that delay discounting paradigms reflect a variety of maladaptive psychosocial outcomes, including substance use pathology. We sought to determine whether a computerized assessment of hypothetical delay discounting (HDD) taps into behavioral impulsivity in a community sample of adolescent twins (N = 675). Using a longitudinal design, we hypothesized that greater HDD at age 14–15 predicts real-world impulsive choices and risk for substance use disorders in late adolescence. We also examined the genetic and environmental structure of HDD performance. Individual differences in HDD behavior showed moderate heritability, and were prospectively associated with real-world temporal discounting at age 17–18. Contrary to expectations, HDD was not consistently related to substance use or trait impulsivity. Although a significant association between HDD behavior and past substance use emerged in males, this effect was mediated by cognitive ability. In both sexes, HDD failed to predict a comprehensive index of substance use problems and behavioral disinhibition in late adolescence. In sum, we present some of the first evidence that HDD performance is heritable and predictive of real-world temporal discounting of rewards. Nevertheless, HDD might not serve as a valid marker of substance use disorder risk in younger adolescents, particularly females. PMID:24999868

  6. Attention-deficit/hyperactivity disorder, delay discounting, and risky financial behaviors: A preliminary analysis of self-report data.

    Directory of Open Access Journals (Sweden)

    Theodore P Beauchaine

    Full Text Available Delay discounting-often referred to as hyperbolic discounting in the financial literature-is defined by a consistent preference for smaller, immediate rewards over larger, delayed rewards, and by failure of future consequences to curtail current consummatory behaviors. Previous research demonstrates (1 excessive delay discounting among individuals with attention-deficit/hyperactivity disorder (ADHD, (2 common neural substrates of delay discounting and hyperactive-impulsive symptoms of ADHD, and (3 associations between delay discounting and both debt burden and high interest rate borrowing. This study extends prior research by examining associations between ADHD symptoms, delay discounting, and an array of previously unevaluated financial outcomes among 544 individuals (mean age 35 years. Controlling for age, income, sex, education, and substance use, ADHD symptoms were associated with delay discounting, late credit card payments, credit card balances, use of pawn services, personal debt, and employment histories (less time spent at more jobs. Consistent with neural models of reward processing and associative learning, more of these relations were attributable to hyperactive-impulsive symptoms than inattentive symptoms. Implications for financial decision-making and directions for future research are discussed.

  7. Attention-deficit/hyperactivity disorder, delay discounting, and risky financial behaviors: A preliminary analysis of self-report data.

    Science.gov (United States)

    Beauchaine, Theodore P; Ben-David, Itzhak; Sela, Aner

    2017-01-01

    Delay discounting-often referred to as hyperbolic discounting in the financial literature-is defined by a consistent preference for smaller, immediate rewards over larger, delayed rewards, and by failure of future consequences to curtail current consummatory behaviors. Previous research demonstrates (1) excessive delay discounting among individuals with attention-deficit/hyperactivity disorder (ADHD), (2) common neural substrates of delay discounting and hyperactive-impulsive symptoms of ADHD, and (3) associations between delay discounting and both debt burden and high interest rate borrowing. This study extends prior research by examining associations between ADHD symptoms, delay discounting, and an array of previously unevaluated financial outcomes among 544 individuals (mean age 35 years). Controlling for age, income, sex, education, and substance use, ADHD symptoms were associated with delay discounting, late credit card payments, credit card balances, use of pawn services, personal debt, and employment histories (less time spent at more jobs). Consistent with neural models of reward processing and associative learning, more of these relations were attributable to hyperactive-impulsive symptoms than inattentive symptoms. Implications for financial decision-making and directions for future research are discussed.

  8. Internet Addiction and Delay Discounting in College Students

    Science.gov (United States)

    Saville, Bryan K.; Gisbert, Amanda; Kopp, Jason; Telesco, Carolyn

    2010-01-01

    To examine the relation between Internet addiction and delay discounting, we gave 276 college students a survey designed to measure Internet addiction and a paper-based delay-discounting task. In our larger sample, we identified 14 students who met the criteria for Internet addiction; we also identified 14 matched controls who were similar to the…

  9. Time and decision making: differential contribution of the posterior insular cortex and the striatum during a delay discounting task.

    Science.gov (United States)

    Wittmann, Marc; Leland, David S; Paulus, Martin P

    2007-06-01

    Delay discounting refers to the fact that an immediate reward is valued more than the same reward if it occurs some time in the future. To examine the neural substrates underlying this process, we studied 13 healthy volunteers who repeatedly had to decide between an immediate and parametrically varied delayed hypothetical reward using a delay discounting task during event-related functional magnetic resonance imaging. Subject's preference judgments resulted in different discounting slopes for shorter ( or =1 year) delays. Neural activation associated with the shorter delays relative to the longer delays was associated with increased activation in the head of the left caudate nucleus and putamen. When individuals selected the delayed relative to the immediate reward, a strong activation was found in bilateral posterior insular cortex. Several brain areas including the left caudate nucleus showed a correlation between the behaviorally determined discounting and brain activation for the contrast of intervals with delays or =1 year. These results suggest that (1) the posterior insula, which is a critical component of the decision-making neural network, is involved in delaying gratification and (2) the degree of neural activation in the striatum, which plays a fundamental role in reward prediction and in time estimation, may code for the time delay.

  10. Delay and probability discounting among payday and title loan recipients.

    Science.gov (United States)

    Mahoney, Colin T; Lawyer, Steven R

    2016-04-01

    Payday and title loans are short-term loans associated with significant economic impact. Behavioral theories of impulsive choice may provide insight into behavioral processes that underlie the propensity to take out payday and title loans. Adults between the ages of 18 and 30 recruited from the community completed delay and probability discounting tasks for hypothetical money as well as measures of substance use. Patterns of discounting were characterized using a hyperbolic decay model and area under the curve. Participants who took out a payday and/or title loan in the past (n=41) exhibited more impulsive choice patterns on the delay discounting task than did those who did not (n=255). Substance use mediated this relationship between payday and title loan retention and delay discounting. These findings suggest potentially important relationships between payday/title loan borrowing, substance use, and delay discounting. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Neural congruence between intertemporal and interpersonal self-control: Evidence from delay and social discounting.

    Science.gov (United States)

    Hill, Paul F; Yi, Richard; Spreng, R Nathan; Diana, Rachel A

    2017-11-15

    Behavioral studies using delay and social discounting as indices of self-control and altruism, respectively, have revealed functional similarities between farsighted and social decisions. However, neural evidence for this functional link is lacking. Twenty-five young adults completed a delay and social discounting task during fMRI scanning. A spatiotemporal partial least squares analysis revealed that both forms of discounting were well characterized by a pattern of brain activity in areas comprising frontoparietal control, default, and mesolimbic reward networks. Both forms of discounting appear to draw on common neurocognitive mechanisms, regardless of whether choices involve intertemporal or interpersonal outcomes. We also observed neural profiles differentiating between high and low discounters. High discounters were well characterized by increased medial temporal lobe and limbic activity. In contrast, low discount rates were associated with activity in the medial prefrontal cortex and right temporoparietal junction. This pattern may reflect biological mechanisms underlying behavioral heterogeneity in discount rates. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Comorbid depression, antisocial personality, and substance dependence: Relationship with delay discounting.

    Science.gov (United States)

    Moody, Lara; Franck, Christopher; Bickel, Warren K

    2016-03-01

    Within the field of addiction, as many as four-fifths of individuals in treatment for substance use disorder have co-existing lifetime psychopathology and as high as two-thirds have current psychopathology. Among substance-dependent individuals, excessive delay discounting is pervasive. Despite evidence of excessive discounting across substance use disorders, few studies have investigated the impact of co-occurring psychopathologies and SUD on delay discounting. We compared delay discounting in currently abstaining substance users with (a) SUD (n=166), (b) SUD and managed major depressive disorder (MDD; n=44), (c) SUD and antisocial personality disorder (APD; n=35), (d) SUD and managed MDD and APD (n=22) and (e) no SUD or co-occurring psychopathology (n=60). All groups with SUD discounted future delayed rewards significantly more than healthy controls (p<0.001 in each case, d=0.686, 0.835, 1.098 and 1.650, respective to groups a-d above). Individuals with both APD and SUD and individuals with MDD, APD, and SUD discounted future rewards significantly more than substance users without comorbid psychopathology (p=0.029, d=0.412 and p<0.001, d=0.964, respectively). Overall, individuals with multiple psychopathologies in addition to substance use have exacerbated deficits in discounting of the future, above and beyond that observed in substance use alone. Increased discounting in combined substance and psychopathology profiles suggest a greater chance of treatment failure and therefore may necessitate individualized treatment using adjunctive interventions to achieve better treatment outcomes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. A dual-process approach to exploring the role of delay discounting in obesity.

    Science.gov (United States)

    Price, Menna; Higgs, Suzanne; Maw, James; Lee, Michelle

    2016-08-01

    Delay discounting of financial rewards has been related to overeating and obesity. Neuropsychological evidence supports a dual-system account of both discounting and overeating behaviour where the degree of impulsive decision making is determined by the relative strength of reward desire and executive control. A dual-parameter model of discounting behaviour is consistent with this theory. In this study, the fit of the commonly used one-parameter model was compared to a new dual-parameter model for the first time in a sample of adults with wide ranging BMI. Delay discounting data from 79 males and females (males=26) across a wide age (M=28.44years (SD=8.81)) and BMI range (M=25.42 (SD=5.16)) was analysed. A dual-parameter model (saturating-hyperbolic; Doya, [Doya (2008) ]) was applied to the data and compared on model fit indices to the single-parameter model. Discounting was significantly greater in the overweight/obese participants using both models, however, the two parameter model showed a superior fit to data (pdual-system account of inter-temporal choice behaviour. The dual-parameter model showed superior fit to data and the two parameters were shown to be related yet distinct indices sensitive to differences between weight groups. Findings are discussed in terms of the impulsive reward and executive control systems that contribute to unhealthy food choice and within the context of obesity related research. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Tobacco demand, delay discounting, and smoking topography among smokers with and without psychopathology.

    Science.gov (United States)

    Farris, Samantha G; Aston, Elizabeth R; Abrantes, Ana M; Zvolensky, Michael J

    2017-10-01

    Tobacco demand (i.e., relative value attributed to a given reinforcer) and delay discounting (i.e., relative preference for smaller immediate rewards over larger delayed rewards) are two behavioral economic processes that are linked to the progression of problematic substance use. These processes have not been studied among those with psychopathology, a vulnerable group of smokers. The current study examined differences in tobacco demand and delay discounting, and their association with smoking topography among smokers with (n=43) and without (n=64) past-year psychopathology. Adult daily smokers (n=107,M age =43.5; SD=9.7) participated in a study on "smoking behavior." Past-year psychological disorders were assessed via a clinician-administered diagnostic assessment. All subjects participated in an ad libitum smoking trial and then completed an assessment of delay discounting (Monetary Choice Questionnaire) and tobacco demand (Cigarette Purchase Task) approximately 45-60min post-smoking. Smokers with psychopathology, compared to those without, had significantly higher demand intensity and maximum expenditure on tobacco (O max ), but did not differ on other demand indices or delay discounting. Smokers with psychopathology had shorter average inter-puff intervals and shorter time to cigarette completion than smokers without psychopathology. Tobacco demand and delay discounting measures were significantly intercorrelated among smokers with psychopathology, but not those without. Both behavioral economic measures were associated with specific aspects of smoking topography in smokers with psychopathology. The association between tobacco demand and delay discounting is evident among smokers with psychopathology and both measures were most consistently related to smoking behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A behavioral economic analysis of texting while driving: Delay discounting processes.

    Science.gov (United States)

    Hayashi, Yusuke; Miller, Kimberly; Foreman, Anne M; Wirth, Oliver

    2016-12-01

    The purpose of the present study was to examine an impulsive decision-making process underlying texting while driving from a behavioral economic perspective. A sample of 108 college students completed a novel discounting task that presented participants with a hypothetical scenario in which, after receiving a text message while driving, they rated the likelihood of replying to a text message immediately versus waiting to reply for a specific period of time. Participants also completed a delay discounting task in which they made repeated hypothetical choices between obtaining a larger amount of money available after a delay and an equal or lesser amount of money available immediately. The results show that the duration of the delay is a critical variable that strongly determines whether participants choose to wait to reply to a text message, and that the decrease in the likelihood of waiting as a function of delay is best described by a hyperbolic delay discounting function. The results also show that participants who self-reported higher frequency of texting while driving discounted the opportunity to reply to a text message at greater rates, whereas there was no relation between the rates of discounting of hypothetical monetary rewards and the frequency of texting while driving. The results support the conclusion that texting while driving is fundamentally an impulsive choice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Delay discounting, treatment motivation and treatment retention among substance-dependent individuals attending an in inpatient detoxification program

    NARCIS (Netherlands)

    Stevens, Laura; Verdejo-García, Antonio; Roeyers, Herbert; Goudriaan, Anna E.; Vanderplasschen, Wouter

    2015-01-01

    Recent studies consistently indicate high rates of delay discounting in drug users, which refers to a strong tendency to devaluate delayed rewards. Many addiction treatment programs however, place high demands on the ability to postpone immediate gratification. Therefore, these programs may be

  17. An adaptive, individualized fMRI delay discounting procedure to increase flexibility and optimize scanner time.

    Science.gov (United States)

    Koffarnus, Mikhail N; Deshpande, Harshawardhan U; Lisinski, Jonathan M; Eklund, Anders; Bickel, Warren K; LaConte, Stephen M

    2017-11-01

    Research on the rate at which people discount the value of future rewards has become increasingly prevalent as discount rate has been shown to be associated with many unhealthy patterns of behavior such as drug abuse, gambling, and overeating. fMRI research points to a fronto-parietal-limbic pathway that is active during decisions between smaller amounts of money now and larger amounts available after a delay. Researchers in this area have used different variants of delay discounting tasks and reported various contrasts between choice trials of different types from these tasks. For instance, researchers have compared 1) choices of delayed monetary amounts to choices of the immediate monetary amounts, 2) 'hard' choices made near one's point of indifference to 'easy' choices that require little thought, and 3) trials where an immediate choice is available versus trials where one is unavailable, regardless of actual eventual choice. These differences in procedure and analysis make comparison of results across studies difficult. In the present experiment, we designed a delay discounting task with the intended capability of being able to construct contrasts of all three comparisons listed above while optimizing scanning time to reduce costs and avoid participant fatigue. This was accomplished with an algorithm that customized the choice trials presented to each participant with the goal of equalizing choice trials of each type. We compared this task, which we refer to here as the individualized discounting task (IDT), to two other delay discounting tasks previously reported in the literature (McClure et al., 2004; Amlung et al., 2014) in 18 participants. Results show that the IDT can examine each of the three contrasts mentioned above, while yielding a similar degree of activation as the reference tasks. This suggests that this new task could be used in delay discounting fMRI studies to allow researchers to more easily compare their results to a majority of previous

  18. Steep Delay Discounting and Addictive Behavior: A Meta-Analysis of Continuous Associations

    Science.gov (United States)

    Amlung, Michael; Vedelago, Lana; Acker, John; Balodis, Iris; MacKillop, James

    2016-01-01

    Aims To synthesize continuous associations between delayed reward discounting (DRD) and both addiction severity and quantity-frequency (QF); to examine moderators of these relationships; and to investigate publication bias. Methods Meta-analysis of published studies examining continuous associations between DRD and addictive behaviors. Published, peer-reviewed studies on addictive behaviors (alcohol, tobacco, cannabis, stimulants, opiates, and gambling) were identified via PubMed, MEDLINE, and PsycInfo. Studies were restricted to DRD measures of monetary gains. Random effects meta-analysis was conducted using Pearson’s r as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger’s tests, meta-regression of publication year and effect size, and imputation of missing studies. Results The primary meta-analysis revealed a small magnitude effect size that was highly significant (r = 0.14, p addictive behavior (p = 0.30) or DRD assessment (p = 0.90). Indices of publication bias suggested a modest impact of unpublished findings. Conclusions Delayed reward discounting is robustly associated with continuous measures of addiction severity and quantity-frequency. This relation is generally robust across type of addictive behavior and delayed reward discounting assessment modality. PMID:27450931

  19. Temporal framing and the hidden-zero effect: rate-dependent outcomes on delay discounting.

    Science.gov (United States)

    Naudé, Gideon P; Kaplan, Brent A; Reed, Derek D; Henley, Amy J; DiGennaro Reed, Florence D

    2018-05-01

    Recent research suggests that presenting time intervals as units (e.g., days) or as specific dates, can modulate the degree to which humans discount delayed outcomes. Another framing effect involves explicitly stating that choosing a smaller-sooner reward is mutually exclusive to receiving a larger-later reward, thus presenting choices as an extended sequence. In Experiment 1, participants (N = 201) recruited from Amazon Mechanical Turk completed the Monetary Choice Questionnaire in a 2 (delay framing) by 2 (zero framing) design. Regression suggested a main effect of delay, but not zero, framing after accounting for other demographic variables and manipulations. We observed a rate-dependent effect for the date-framing group, such that those with initially steep discounting exhibited greater sensitivity to the manipulation than those with initially shallow discounting. Subsequent analyses suggest these effects cannot be explained by regression to the mean. Experiment 2 addressed the possibility that the null effect of zero framing was due to within-subject exposure to the hidden- and explicit-zero conditions. A new Amazon Mechanical Turk sample completed the Monetary Choice Questionnaire in either hidden- or explicit-zero formats. Analyses revealed a main effect of reward magnitude, but not zero framing, suggesting potential limitations to the generality of the hidden-zero effect. © 2018 Society for the Experimental Analysis of Behavior.

  20. Impairment in delay discounting in schizophrenia and schizoaffective disorder but not primary mood disorders.

    Science.gov (United States)

    Brown, Hannah E; Hart, Kamber L; Snapper, Leslie A; Roffman, Joshua L; Perlis, Roy H

    2018-05-28

    A measure of planning and impulse control, the delay-discounting (DD) task estimates the extent to which an individual decreases the perceived value of a reward as the reward is delayed. We examined cross-disorder performance between healthy controls (n = 88), individuals with bipolar disorder (n = 23), major depressive disorder (n = 43), and primary psychotic disorders (schizophrenia and schizoaffective disorder; n = 51) on the DD task (using a $10 delayed larger reward), as well as the interaction of DD scores with other symptom domains (cognition, psychosis, and affect). We found that individuals with schizophrenia and schizoaffective disorder display significantly greater rates of discounting compared to healthy controls, while individuals with a primary mood disorder do not differ from healthy controls after adjustment for IQ. Further, impairment in working memory is associated with higher discounting rates among individuals with schizophrenia and schizoaffective disorder, but cognitive dysfunction alone does not account for the extent of impairment in DD. Taken together, these results suggest an impaired ability to plan for the future and make adaptive decisions that are specific to individuals with psychotic disorders, and likely related to adverse functional outcomes. More generally, this work demonstrates the presence of variation in impulsivity across major psychiatric illnesses, supporting the use of a trans-diagnostic perspective.

  1. Estimating the subjective value of future rewards: comparison of adjusting-amount and adjusting-delay procedures.

    Science.gov (United States)

    Holt, Daniel D; Green, Leonard; Myerson, Joel

    2012-07-01

    The present study examined whether equivalent discounting of delayed rewards is observed with different experimental procedures. If the underlying decision-making process is the same, then similar patterns of results should be observed regardless of procedure, and similar estimates of the subjective value of future rewards (i.e., indifference points) should be obtained. Two experiments compared discounting on three types of procedure: adjusting-delay (AD), adjusting-immediate-amount (AIA), and adjusting-delayed-amount (ADA). For the two procedures for which discounting functions can be established (i.e., AD and AIA), a hyperboloid provided good fits to the data at both the group and individual levels, and individuals' discounting on one procedure tended to be correlated with their discounting on the other. Notably, the AIA procedure produced the more consistent estimates of the degree of discounting, and in particular, discounting on the AIA procedure was unaffected by the order in which choices were presented. Regardless of which of the three procedures was used, however, similar patterns of results were obtained: Participants systematically discounted the value of delayed rewards, and robust magnitude effects were observed. Although each procedure may have its own advantages and disadvantages, use of all three types of procedure in the present study provided converging evidence for common decision-making processes underlying the discounting of delayed rewards. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Concurrent progressive-ratio schedules: built-in controls in the study of delayed reward efficacy.

    Science.gov (United States)

    Jarmolowicz, David P; Hudnall, Jennifer L

    2014-08-15

    Delayed rewards maintain lower rates of operant responding than immediate rewards, and when given a choice between immediate and delayed rewards, individuals typically choose the immediate reward, even when it is smaller (a phenomenon called delay discounting). The behavioral and neural mechanisms underlying these behavioral patterns, however, are not conclusively understood. The present study developed a method to examine the efficacy of delayed rewards in a way that is suitable for pharmacological manipulation of delayed reward efficacy (while controlling for general changes in reward efficacy). The progressive ratio (PR) paradigm often used to examine reward efficacy was modified such that two PR schedules for lever pressing concurrently yet independently were presented. Across a series of conditions, a range of delays (3-81s) were arranged on one of the levers while the reward on the other lever remained immediate. PR breakpoints (the highest ratio completed on each lever, our measure of reward efficacy) systematically decreased on the delayed, but not on the immediate reward lever, suggesting that delays decreased reward efficacy. This decrease in breakpoint resulted in bias in within-session responding that was accounted for by models that adjusted reward value by the delay to that reward. Unlike the standard PR paradigm, the present arrangement provided the controls needed to differentiate delay specific from general changes in reward efficacy. The present method should be helpful in the study of the behavioral and neural mechanisms of delayed reward efficacy. Modifications of the present paradigm should be useful for pharmacological studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Measuring and modeling the interaction among reward size, delay to reward, and satiation level on motivation in monkeys.

    Science.gov (United States)

    Minamimoto, Takafumi; La Camera, Giancarlo; Richmond, Barry J

    2009-01-01

    Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e.g., the identity, amount, and timing of a rewarding outcome) and internal factors (e.g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations that are similar to those found in free operant and choice tasks. The fraction of correct trials also decreased progressively as a function of the satiation level. Similar (albeit noiser) relations were obtained for reaction times. The combined effect of reward size, delay-to-reward, and satiation level on the proportion of correct trials is well described as a multiplication of the effects of the single factors when each factor is examined alone. These results provide a quantitative account of the interaction of external and internal factors on instrumental behavior, and allow us to extend the concept of subjective value of a rewarding outcome, usually confined to external factors, to account also for slow changes in the internal drive of the subject.

  4. Alcohol Increases Delay and Probability Discounting of Condom-Protected Sex: A Novel Vector for Alcohol-Related HIV Transmission.

    Science.gov (United States)

    Johnson, Patrick S; Sweeney, Mary M; Herrmann, Evan S; Johnson, Matthew W

    2016-06-01

    Alcohol use, especially at binge levels, is associated with sexual HIV risk behavior, but the mechanisms through which alcohol increases sexual risk taking are not well-examined. Delay discounting, that is, devaluation of future consequences as a function of delay to their occurrence, has been implicated in a variety of problem behaviors, including risky sexual behavior. Probability discounting is studied with a similar framework as delay discounting, but is a distinct process in which a consequence is devalued because it is uncertain or probabilistic. Twenty-three, nondependent alcohol users (13 male, 10 female; mean age = 25.3 years old) orally consumed alcohol (1 g/kg) or placebo in 2 separate experimental sessions. During sessions, participants completed tasks examining delay and probability discounting of hypothetical condom-protected sex (Sexual Delay Discounting Task, Sexual Probability Discounting Task) and of hypothetical and real money. Alcohol decreased the likelihood that participants would wait to have condom-protected sex versus having immediate, unprotected sex. Alcohol also decreased the likelihood that participants would use an immediately available condom given a specified level of sexually transmitted infection (STI) risk. Alcohol did not affect delay discounting of money, but it did increase participants' preferences for larger, probabilistic monetary rewards over smaller, certain rewards. Acute, binge-level alcohol intoxication may increase sexual HIV risk by decreasing willingness to delay sex in order to acquire a condom in situations where one is not immediately available, and by decreasing sensitivity to perceived risk of STI contraction. These findings suggest that delay and probability discounting are critical, but heretofore unrecognized, processes that may mediate the relations between alcohol use and HIV risk. Copyright © 2016 by the Research Society on Alcoholism.

  5. Delay discounting, risk-taking, and rejection sensitivity among individuals with Internet and Video Gaming Disorders.

    Science.gov (United States)

    Weinstein, Aviv; Abu, Hodaya Ben; Timor, Ayelet; Mama, Yaniv

    2016-12-01

    Background and aims There is a previous evidence for impulsivity in individuals with Internet and Video Gaming Disorders. The aim of this study was to examine whether Internet and video game addictions are associated with experiential delay discounting, risk-taking, and sensitivity to social rejection using computerized tasks and questionnaires. Methods Twenty participants (mean age 24, SD = 1.55) with high score on the Problematic Online Gaming Questionnaire (POGQ) were compared with 20 participants (mean age 24.8, SD = 1.34) with low score on the POGQ. They performed on computerized Balloon Analog Risk Task and Experiential Delay discounting Task (EDT), and filled in the sensitivity to social rejection questionnaire. Results Participants with high POGQ scores had lower measures of delay discounting, higher measures of risk-taking, and higher measures of sensitivity to social rejection compared with participants with low POGQ scores. Discussion The results of this study support the previous evidence of risk-taking and provide new evidence for difficulties in delay discounting and sensitivity to social rejection among those who score high on Internet and video games. Conclusions The results suggest that Internet- and video game-addicted individuals seek immediate gratification and cannot wait for later reward. Furthermore, these individuals spend time in the virtual world, where they feel safe, and avoid social interactions presumably due to fears of social rejection.

  6. Delay discounting mediates the association between posterior insular cortex volume and social media addiction symptoms.

    Science.gov (United States)

    Turel, Ofir; He, Qinghua; Brevers, Damien; Bechara, Antoine

    2018-04-25

    Addiction-like symptoms in relation to excessive and compulsive social media use are common in the general population. Because they can lead to various adverse effects, there is a growing need to understand the brain systems and processes that are involved in potential social media addiction. We focus on the morphology of the posterior subdivision of the insular cortex (i.e., the insula), because it has been shown to be instrumental to supporting the maintenance of substance addictions and problematic behaviors. Assuming that social media addiction shares neural similarities with more established ones and consistent with evidence from the neuroeconomics domain, we further examine one possible reason for this association-namely that insular morphology influences one's delay discounting and that this delay discounting contributes to exaggerated preference for immediate social media rewards and consequent addiction-like symptoms. Based on voxel-based morphometry techniques applied to MRI scans of 32 social media users, we show that the gray matter volumes of the bilateral posterior insula are negatively associated with social media addiction symptoms. We further show that this association is mediated by delay discounting. This provides initial evidence that insular morphology can be associated with potential social media addiction, in part, through its contribution to poor foresight and impulsivity as captured by delay discounting.

  7. Investigating the Impact of Cognitive Load and Motivation on Response Control in Relation to Delay Discounting in Children with ADHD.

    Science.gov (United States)

    Martinelli, Mary K; Mostofsky, Stewart H; Rosch, Keri S

    2017-10-01

    Attention-deficit/hyperactivity disorder (ADHD) is characterized by deficits in impulse control across a range of behaviors, from simple actions to those involving complex decision-making (e.g., preference for smaller-sooner versus larger later rewards). This study investigated whether changes in motor response control with increased cognitive load and motivational contingencies are associated with decision-making in the form of delay discounting among 8-12 year old children with and without ADHD. Children with ADHD (n = 26; 8 girls) and typically developing controls (n = 40; 11 girls) completed a standard go/no-go (GNG) task, a GNG task with motivational contingencies, a GNG task with increased cognitive load, and two measures of delay discounting: a real-time task in which the delays and immediately consumable rewards are experienced in real-time, and a classic task involving choices about money at longer delays. Children with ADHD, particularly girls, exhibited greater delay discounting than controls during the real-time discounting task, whereas diagnostic groups did not significantly differ on the classic discounting task. The effect of cognitive load on response control was uniquely associated with greater discounting on the real-time task for children with ADHD, but not for control children. The effect of motivational contingencies on response control was not significantly associated with delay discounting for either diagnostic group. The findings from this study help to inform our understanding of the factors that influence deficient self-control in ADHD, suggesting that impairments in cognitive control may contribute to greater delay discounting in ADHD.

  8. Future so bright? Delay discounting and consideration of future consequences predict academic performance among college drinkers.

    Science.gov (United States)

    Acuff, Samuel F; Soltis, Kathryn E; Dennhardt, Ashley A; Borsari, Brian; Martens, Matthew P; Murphy, James G

    2017-10-01

    College student drinking is a major public health concern and can result in a range of negative consequences, from acute health risks to decreased academic performance and drop out. Harm reduction interventions have been developed to reduce problems associated with drinking but there is a need to identify specific risk/protective factors related to academic performance among college drinkers. Behavioral economics suggests that chronic alcohol misuse reflects a dysregulated behavioral process or reinforcer pathology-alcohol is overvalued and the value of prosocial rewards are sharply discounted due, in part, to their delay. This study examined delay discounting, consideration of future consequences (CFC) and protective behavioral strategies (PBS) as predictors of academic success (grade point average; GPA) and engagement (time devoted to academic activities) among 393 college drinkers (61% female). In multivariate models, PBS were associated with greater academic engagement, but were not with academic success. Lower discounting of delayed rewards and greater CFC were associated with both academic success and engagement among drinkers. Previous research suggests that future time orientation is malleable, and the current results provide support for efforts to enhance future time orientation as part of alcohol harm-reduction approaches. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  9. Age Differences in Future Orientation and Delay Discounting

    Science.gov (United States)

    Steinberg, Laurence; Graham, Sandra; O'Brien, Lia; Woolard, Jennifer; Cauffman, Elizabeth; Banich, Marie

    2009-01-01

    Age differences in future orientation are examined in a sample of 935 individuals between 10 and 30 years using a delay discounting task as well as a new self-report measure. Younger adolescents consistently demonstrate a weaker orientation to the future than do individuals aged 16 and older, as reflected in their greater willingness to accept a…

  10. Relation between Time Perspective and Delay Discounting: A Literature Review

    Science.gov (United States)

    Teuscher, Ursina; Mitchell, Suzanne H.

    2011-01-01

    In this article, we examine the relation between delay discounting and future time perspective by reviewing how these concepts have been measured and quantified in order to assess their conceptual similarities. The extent to which the different measures are empirically related is reviewed by describing studies that have assessed both constructs…

  11. Capacity to Delay Reward Differentiates Obsessive Compulsive Disorder and Obsessive Compulsive Personality Disorder

    Science.gov (United States)

    Pinto, Anthony; Steinglass, Joanna E.; Greene, Ashley L.; Weber, Elke U.; Simpson, H. Blair

    2013-01-01

    Background Although the relationship between obsessive compulsive disorder (OCD) and obsessive compulsive personality disorder (OCPD) has long been debated, clinical samples of OCD (without OCPD) and OCPD (without OCD) have never been systematically compared. We studied whether individuals with OCD, OCPD, or both conditions differ on symptomatology, functioning, and a measure of self-control: the capacity to delay reward. Methods 25 OCD, 25 OCPD, 25 comorbid OCD+OCPD, and 25 healthy controls (HC) completed clinical assessments and a validated intertemporal choice task that measures capacity to forego small immediate rewards for larger delayed rewards. Results OCD and OCPD subjects both showed impairment in psychosocial functioning and quality of life, as well as compulsive behavior, but only subjects with OCD reported obsessions. Individuals with OCPD, with or without comorbid OCD, discounted the value of delayed monetary rewards significantly less than OCD and HC. This excessive capacity to delay reward discriminates OCPD from OCD, and is associated with perfectionism and rigidity. Conclusions OCD and OCPD are both impairing disorders marked by compulsive behaviors, but they can be differentiated by the presence of obsessions in OCD and by excessive capacity to delay reward in OCPD. That individuals with OCPD show less temporal discounting (suggestive of excessive self-control) whereas prior studies have shown that individuals with substance use disorders show greater discounting (suggestive of impulsivity) supports the premise that this component of self-control lies on a continuum in which both extremes (impulsivity and overcontrol) contribute to psychopathology. PMID:24199665

  12. The role of prospection in steep temporal reward discounting in gambling addiction

    Directory of Open Access Journals (Sweden)

    Antonius eWiehler

    2015-08-01

    Full Text Available Addiction and pathological gambling (PG have been consistently associated with high impulsivity and a steep devaluation of delayed rewards, a process that is known as temporal discounting (TD. Recent studies indicated that enhanced episodic future thinking (EFT results in less impulsive TD in healthy controls (HC. In a separate line of research, it has been suggested that non-linearities in time perception might contribute to reward devaluation during inter-temporal choice. Therefore, in addition to deficits in valuation processes and executive control, impairments in EFT and non-linearities in time perception have been hypothesized to contribute to steep TD in addiction. In this study, we explore such a potential association of impairments in EFT and time perception with steep TD in PG.We investigated 20 PGs and 20 matched HCs. TD was assessed via a standard computerized binary choice task. We measured EFT using a variation of the Autobiographical Memory Interview by Levine et al. (1. Time perception was assessed with a novel task, utilizing a non-linear rating procedure via circle-size adjustments.Groups did not differ in baseline EFT. In both groups, a power law accounted time perception best, and the degree of non-linearity in time perception correlated with discounting across groups. A multiple regression analysis across all predictors and covariates revealed that only group status (PG/HC and depression were significantly associated with discounting behavior such that PG increased TD and depression attenuated TD.Our findings speak against the idea that steep TD in PG is due to a skewed perception of time or impairments in EFT, at least under the present task conditions. The lack of overall group differences in EFT does not rule out the possibility of more complex interactions of EFT and decision-making. These interactions might be diminished in pathological gambling or addiction more generally, when other task configurations are used.

  13. An Examination of The Transdiagnostic Role of Delay Discounting in Psychological Inflexibility and Mental Health Problems

    OpenAIRE

    Levin, Michael; Haeger, Jack; Ong, Clarissa W.; Twohig, Michael P.

    2018-01-01

    Delay discounting is a basic behavioral process that has been found to predict addictive behaviors, and more recently, other mental health problems. Acceptance and Commitment Therapy (ACT), is a transdiagnostic treatment that appears to alter delay discounting, possibly through reducing psychological inflexibility. The current study sought to further bridge research on delay discounting and ACT by examining the relation of delay discounting to a broad range of selfreported mental health probl...

  14. Me, Myself, and Money II: Relative Deprivation Predicts Disordered Gambling Severity via Delay Discounting, Especially Among Gamblers Who Have a Financially Focused Self-Concept.

    Science.gov (United States)

    Tabri, Nassim; Will Shead, N; Wohl, Michael J A

    2017-12-01

    In the current research, we examined whether the known link between relative deprivation and disordered gambling (via delay discounting; i.e., preferences for immediate smaller rewards relative to delayed larger rewards) is moderated by the extent to which gamblers have a financially focused self-concept. Specifically, we hypothesized that delay discounting would be a strong predictor of disordered gambling among those who base their self-worth on their financial success. To test this moderated-mediation model, a community sample of gamblers (N = 239) completed measures that assessed relative deprivation, delay discounting, financially focused self-concept, and disordered gambling severity. As predicted, people who felt more relative deprivation reported more severe symptoms of disordered gambling and this association was mediated by delay discounting. Importantly, this mediated relationship was moderated by the extent to which participants' self-concept was focused on financial success. Among participants whose self-concept was high in financial focus, greater delay discounting (stemming from relative deprivation) was a strong predictor of disordered gambling. Among people whose self-concept was low in financial focus, delay discounting (stemming from relative deprivation) was a weak predictor of disordered gambling. Thus, the magnitude of the indirect effect of relative deprivation on disordered gambling severity was larger among people with a more financially focused self-concept-an effect mediated by delay discounting. These findings suggest that targeting gamblers' financial focus in prevention and treatment interventions may be instrumental in curtailing the development and maintenance of disordered gambling.

  15. Discounting of Various Types of Rewards by Women with and without Binge Eating Disorder: Evidence for General Rather than Specific Differences

    Science.gov (United States)

    Manwaring, Jamie L.; Green, Leonard; Myerson, Joel; Strube, Michael J.; Wilfley, Denise E.

    2011-01-01

    The present study compared the extent to which obese women with binge eating disorder (BED), obese women without BED, and controls discounted delayed and probabilistic money and directly consumable rewards: food, massage time, and preferred sedentary activity. Of special interest was whether the BED group differed from the other groups in terms of…

  16. Delay discounting as a function of intrinsic/extrinsic religiousness, religious fundamentalism, and regular church attendance.

    Science.gov (United States)

    Weatherly, Jeffrey N; Plumm, Karyn M

    2012-01-01

    Delay discounting occurs when the subjective value of an outcome decreases because its delivery is delayed. Previous research has suggested that the rate at which some, but not all, outcomes are discounted varies as a function of regular church attendance. In the present study, 509 participants completed measures of intrinsic religiousness, extrinsic religiousness, religious fundamentalism, and whether they regularly attended church services. They then completed a delay-discounting task involving five outcomes. Although religiousness was not a significant predictor of discounting for all outcomes, participants scoring high in intrinsic religiousness tended to display less delay discounting than participants scoring low. Likewise, participants scoring high in religious fundamentalism tended to display more delay discounting than participants scoring low. These results partially replicate previous ones in showing that the process of discounting may vary as a function of religiousness. The results also provide some direction for those interested in altering how individuals discount.

  17. Decisions in Motion: Decision Dynamics during Intertemporal Choice reflect Subjective Evaluation of Delayed Rewards

    Science.gov (United States)

    O'Hora, Denis; Carey, Rachel; Kervick, Aoife; Crowley, David; Dabrowski, Maciej

    2016-02-01

    People tend to discount rewards or losses that occur in the future. Such delay discounting has been linked to many behavioral and health problems, since people choose smaller short-term gains over greater long-term gains. We investigated whether the effect of delays on the subjective value of rewards is expressed in how people move when they make choices. Over 600 patrons of the RISK LAB exhibition hosted by the Science Gallery DublinTM played a short computer game in which they used a computer mouse to choose between amounts of money at various delays. Typical discounting effects were observed and decision dynamics indicated that choosing smaller short-term rewards became easier (i.e., shorter response times, tighter trajectories, less vacillation) as the delays until later rewards increased. Based on a sequence of choices, subjective values of delayed outcomes were estimated and decision dynamics during initial choices predicted these values. Decision dynamics are affected by subjective values of available options and thus provide a means to estimate such values.

  18. "What time is my next meal?" delay-discounting individuals choose smaller portions under conditions of uncertainty.

    Science.gov (United States)

    Zimmerman, Annie R; Ferriday, Danielle; Davies, Sarah R; Martin, Ashley A; Rogers, Peter J; Mason, Alice; Brunstrom, Jeffrey M

    2017-09-01

    'Dietary' delay discounting is typically framed as a trade-off between immediate rewards and long-term health concerns. Our contention is that prospective thinking also occurs over shorter periods, and is engaged to select portion sizes based on the interval between meals (inter-meal interval; IMI). We sought to assess the extent to which the length of an IMI influences portion-size selection. We predicted that delay discounters would show 'IMI insensitivity' (relative lack of concern about hunger or fullness between meals). In particular, we were interested in participants' sensitivity to an uncertain IMI. We hypothesized that when meal times were uncertain, delay discounters would be less responsive and select smaller portion sizes. Participants (N = 90) selected portion sizes for lunch. In different trials, they were told to expect dinner at 5pm, 9pm, and either 5pm or 9pm (uncertain IMI). Individual differences in future-orientation were measured using a monetary delay-discounting task. Participants chose larger portions when the IMI was longer (p relationship between BMI and smaller portion selection in uncertainty (p < 0.05). This is the first study to report an association between delay discounting and IMI insensitivity. We reason that delay discounters selected smaller portions because they were less sensitive to the uncertain IMI, and overlooked concerns about potential future hunger. These findings are important because they illustrate that differences in discounting are expressed in short-term portion-size decisions and suggest that IMI insensitivity increases when meal timings are uncertain. Further research is needed to confirm whether these findings generalise to other populations. Copyright © 2017. Published by Elsevier Ltd.

  19. Withdrawal-Related Changes in Delay Discounting Predict Short-Term Smoking Abstinence.

    Science.gov (United States)

    Miglin, Rickie; Kable, Joseph W; Bowers, Maureen E; Ashare, Rebecca L

    2017-06-01

    Impulsive decision making is associated with smoking behavior and reflects preferences for smaller, immediate rewards and intolerance of temporal delays. Nicotine withdrawal may alter impulsive decision making and time perception. However, little is known about whether withdrawal-related changes in decision making and time perception predict smoking relapse. Forty-five smokers (14 female) completed two laboratory sessions, one following 24-hour abstinence and one smoking-as-usual (order counterbalanced; biochemically verified abstinence). During each visit, participants completed measures of time perception, decision making (ie, discount rates), craving, and withdrawal. Following the second laboratory session, subjects underwent a well-validated model of short-term abstinence (quit week) with small monetary incentives for each day of biochemically confirmed abstinence. Smokers significantly overestimated time during abstinence, compared to smoking-as-usual (p = .021), but there were no abstinence effects on discount rates (p = .6). During the quit week, subjects were abstinent for 3.5 days (SD = 2.15) and smoked a total of 12.9 cigarettes (SD = 15.8). Importantly, higher discount rates (ie, preferences for immediate rewards) during abstinence (abstinence minus smoking difference score) predicted greater number of days abstinent (p = .01) and fewer cigarettes smoked during the quit week (p = .02). Withdrawal-related change in time reproduction did not predict relapse (p = .2). These data suggest that individuals who have a greater preference for immediate rewards during abstinence (vs. smoking-as-usual) may be more successful at maintaining short-term abstinence when provided with frequent (eg, daily) versus less frequent incentive schedules (eg, 1 month). Abstinence-induced changes in decision making may be important for identifying smokers who may benefit from interventions that incentivize abstinence such as contingency management (CM). The present results

  20. Biased and less sensitive: A gamified approach to delay discounting in heroin addiction.

    Science.gov (United States)

    Scherbaum, Stefan; Haber, Paul; Morley, Kirsten; Underhill, Dylan; Moustafa, Ahmed A

    2018-03-01

    People with addiction will continue to use drugs despite adverse long-term consequences. We hypothesized (a) that this deficit persists during substitution treatment, and (b) that this deficit might be related not only to a desire for immediate gratification, but also to a lower sensitivity for optimal decision making. We investigated how individuals with a history of heroin addiction perform (compared to healthy controls) in a virtual reality delay discounting task. This novel task adds to established measures of delay discounting an assessment of the optimality of decisions, especially in how far decisions are influenced by a general choice bias and/or a reduced sensitivity to the relative value of the two alternative rewards. We used this measure of optimality to apply diffusion model analysis to the behavioral data to analyze the interaction between decision optimality and reaction time. The addiction group consisted of 25 patients with a history of heroin dependency currently participating in a methadone maintenance program; the control group consisted of 25 healthy participants with no history of substance abuse, who were recruited from the Western Sydney community. The patient group demonstrated greater levels of delay discounting compared to the control group, which is broadly in line with previous observations. Diffusion model analysis yielded a reduced sensitivity for the optimality of a decision in the patient group compared to the control group. This reduced sensitivity was reflected in lower rates of information accumulation and higher decision criteria. Increased discounting in individuals with heroin addiction is related not only to a generally increased bias to immediate gratification, but also to reduced sensitivity for the optimality of a decision. This finding is in line with other findings about the sensitivity of addicts in distinguishing optimal from nonoptimal choice options.

  1. Concordance between monetary and sexual delay discounting in men who have sex with men.

    Science.gov (United States)

    Jones, Jeb; Guest, Jodie L; Sullivan, Patrick S; Kramer, Michael R; Jenness, Samuel M; Sales, Jessica M

    2017-12-07

    Background: Delay discounting has been found to be associated with numerous health-related outcomes, including risky sexual behaviour. To date, it is unclear whether delay discounting measured in different domains is associated within individuals. The goal of this study was to assess the concordance of monetary and sexual delay discounting in men who have sex with men. Methods: Participants completed an online survey, including the Monetary Choice Questionnaire and the Sexual Discounting Task. Linear regression models were used to assess the association between monetary and sexual discount rates. Results: Sexual discount rates did not predict monetary discount rates. There was a substantial amount of clustering of sexual discount rates, requiring sexual discounting data to be categorised. Conclusions: Monetary and sexual delay discounting are distinct processes that are not necessarily associated within individuals, and monetary delay discounting is not an appropriate proxy measure for sexual impulsivity. Data from the Sexual Discounting Task are typically rank-transformed for analysis. These data suggest that this might be an invalid method of analysis. Future studies should investigate the distribution of their data to determine if it is appropriate to analyse sexual discounting data as a continuous measure.

  2. Does goal relevant episodic future thinking amplify the effect on delay discounting?

    Science.gov (United States)

    O'Donnell, Sara; Oluyomi Daniel, Tinuke; Epstein, Leonard H

    2017-05-01

    Delay discounting (DD) is the preference for smaller immediate rewards over larger delayed rewards. Research shows episodic future thinking (EFT), or mentally simulating future experiences, reframes the choice between small immediate and larger delayed rewards, and can reduce DD. Only general EFT has been studied, whereby people reframe decisions in terms of non-goal related future events. Since future thinking is often goal-oriented and leads to greater activation of brain regions involved in prospection, goal-oriented EFT may be associated with greater reductions in DD than general goal-unrelated EFT. The present study (n=104, M age =22.25, SD=3.42; 50% Female) used a between-subjects 2×2 factorial design with type of episodic thinking (Goal, General) and temporal perspective (Episodic future versus recent thinking; EFT vs ERT) as between factors. Results showed a significant reduction in DD for EFT groups (p<0.001, Cohen's d effect size=0.89), and goal-EFT was more effective than general-EFT on reducing DD (p=0.03, d=0.64). Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Unique prediction of cannabis use severity and behaviors by delay discounting and behavioral economic demand.

    Science.gov (United States)

    Strickland, Justin C; Lile, Joshua A; Stoops, William W

    2017-07-01

    Few studies have simultaneously evaluated delay discounting and behavioral economic demand to determine their unique contribution to drug use. A recent study in cannabis users found that monetary delay discounting uniquely predicted cannabis dependence symptoms, whereas cannabis demand uniquely predicted use frequency. This study sought to replicate and extend this research by evaluating delay discounting and behavioral economic demand measures for multiple commodities and including a use quantity measure. Amazon.com's Mechanical Turk was used to sample individuals reporting recent cannabis use (n=64) and controls (n=72). Participants completed measures of monetary delay discounting as well as alcohol and cannabis delay discounting and demand. Cannabis users and controls did not differ on monetary delay discounting or alcohol delay discounting and demand. Among cannabis users, regression analyses indicated that cannabis delay discounting uniquely predicted use severity, whereas cannabis demand uniquely predicted use frequency and quantity. These effects remained significant after controlling for other delay discounting and demand measures. This research replicates previous outcomes relating delay discounting and demand with cannabis use and extends them by accounting for the contribution of multiple commodities. This research also demonstrates the ability of online crowdsourcing methods to complement traditional human laboratory techniques. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Temporal Discounting of Hypothetical Monetary Rewards by Adolescents, Adults, and Older Adults

    Science.gov (United States)

    Whelan, Robert; McHugh, Louise A.

    2009-01-01

    The present experiment examined temporal discounting across 3 different age bands: adolescents, adults, and older adults (mean ages 14, 46, and 73 years, respectively). A computerized task was employed in which participants were asked to choose between larger rewards available at a specified time in the future--either 100 British Pounds or 1,000…

  5. The impact of depressed mood, working memory capacity, and priming on delay discounting.

    Science.gov (United States)

    Szuhany, Kristin L; MacKenzie, Danny; Otto, Michael W

    2018-09-01

    The impaired ability to delay rewards, delay discounting (DD), is associated with several problematic conditions in which impulsive decision-making derails long-term goals. Working memory (WM), the ability to actively store and manipulate information, is associated with DD. The purpose of this study was to examine the effect of cognitive priming on DD and to identify moderation of this effect dependent on degree of WM capacity (WMC) and depressed mood. A WM task (n-back) was used as a cognitive prime before assessment of DD (Monetary Choice Questionnaire) and was compared to a similar prime from an inhibition task in a factorial design in 183 community participants. All participants completed a DD task and assessment of depressive symptoms (Beck Depression Inventory-II). Priming effects were evaluated relative to WMC of participants. Higher WMC and lower depression scores were associated with greater relative preference for larger, delayed rewards. The effects of a WM prime were moderated by WMC; benefits of the prime were only evident for individuals with lower WMC. No effects were found for an alternative inhibition task. Limitations included depression scores mainly in subclinical range, use of hypothetical instead of real rewards in the DD task, and no examination of the time course of effects. This study provides support for the effectiveness of a brief WM prime in enhancing ability to delay rewards. Priming may be a useful adjunctive intervention for individuals with WM dysfunction or conditions in which impulsive decision-making may derail long-term goals. Copyright © 2018. Published by Elsevier Ltd.

  6. Capacity to delay reward differentiates obsessive-compulsive disorder and obsessive-compulsive personality disorder.

    Science.gov (United States)

    Pinto, Anthony; Steinglass, Joanna E; Greene, Ashley L; Weber, Elke U; Simpson, H Blair

    2014-04-15

    Although the relationship between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD) has long been debated, clinical samples of OCD (without OCPD) and OCPD (without OCD) have never been systematically compared. We studied whether individuals with OCD, OCPD, or both conditions differ on symptomatology, functioning, and a measure of self-control: the capacity to delay reward. Twenty-five OCD, 25 OCPD, 25 comorbid OCD + OCPD, and 25 healthy control subjects completed clinical assessments and a validated intertemporal choice task that measures capacity to forego small immediate rewards for larger delayed rewards. OCD and OCPD subjects both showed impairment in psychosocial functioning and quality of life, as well as compulsive behavior, but only subjects with OCD reported obsessions. Individuals with OCPD, with or without comorbid OCD, discounted the value of delayed monetary rewards significantly less than OCD and healthy control subjects. This excessive capacity to delay reward discriminates OCPD from OCD and is associated with perfectionism and rigidity. OCD and OCPD are both impairing disorders marked by compulsive behaviors, but they can be differentiated by the presence of obsessions in OCD and by excessive capacity to delay reward in OCPD. That individuals with OCPD show less temporal discounting (suggestive of excessive self-control), whereas prior studies have shown that individuals with substance use disorders show greater discounting (suggestive of impulsivity), supports the premise that this component of self-control lies on a continuum in which both extremes (impulsivity and overcontrol) contribute to psychopathology. © 2013 Society of Biological Psychiatry Published by Society of Biological Psychiatry All rights reserved.

  7. Delay discounting of food by rhesus monkeys: Cocaine and food choice in isomorphic and allomorphic situations.

    Science.gov (United States)

    Huskinson, Sally L; Woolverton, William L; Green, Leonard; Myerson, Joel; Freeman, Kevin B

    2015-06-01

    Research on delay discounting has focused largely on nondrug reinforcers in an isomorphic context in which choice is between alternatives that involve the same type of reinforcer. Less often, delay discounting has been studied with drug reinforcers in a more ecologically valid allomorphic context where choice is between alternatives involving different types of reinforcers. The present experiment is the first to examine discounting of drug and nondrug reinforcers in both isomorphic and allomorphic situations using a theoretical model (i.e., the hyperbolic discounting function) that allows for comparisons of discounting rates between reinforcer types and amounts. The goal of the current experiment was to examine discounting of a delayed, nondrug reinforcer (food) by male rhesus monkeys when the immediate alternative was either food (isomorphic situation) or cocaine (allomorphic situation). In addition, we sought to determine whether there was a magnitude effect with delayed food in the allomorphic situation. Choice of immediate food and immediate cocaine increased with amount and dose, respectively. Choice functions for immediate food and cocaine generally shifted leftward as delay increased. Compared to isomorphic situations in which food was the immediate alternative, delayed food was discounted more steeply in allomorphic situations where cocaine was the immediate alternative. Notably, discounting was not affected by the magnitude of the delayed reinforcer. These data indicate that how steeply a delayed nondrug reinforcer is discounted may depend more on the qualitative characteristics of the immediate reinforcer and less on the magnitude of the delayed one. (c) 2015 APA, all rights reserved).

  8. Narrative theory: II. Self-generated and experimenter-provided negative income shock narratives increase delay discounting.

    Science.gov (United States)

    Mellis, Alexandra M; Snider, Sarah E; Bickel, Warren K

    2018-04-01

    Reading experimenter-provided narratives of negative income shock has been previously demonstrated to increase impulsivity, as measured by discounting of delayed rewards. We hypothesized that writing these narratives would potentiate their effects of negative income shock on decision-making more than simply reading them. In the current study, 193 cigarette-smoking individuals from Amazon Mechanical Turk were assigned to either read an experimenter-provided narrative or self-generate a narrative describing either the negative income shock of job loss or a neutral condition of job transfer. Individuals then completed a task of delay discounting and measures of affective response to narratives, as well as rating various narrative qualities such as personal relevance and vividness. Consistent with past research, narratives of negative income shock increased delay discounting compared to control narratives. No significant differences existed in delay discounting after self-generating compared to reading experimenter-provided narratives. Positive affect was lower and negative affect was higher in response to narratives of job loss, but affect measures did not differ based on whether narratives were experimenter-provided or self-generated. All narratives were rated as equally realistic, but self-generated narratives (whether negative or neutral) were rated as more vivid and relevant than experimenter-provided narratives. These results indicate that the content of negative income shock narratives, regardless of source, consistently drives short-term choices. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  9. Discounting of qualitatively different delayed health outcomes in current and never smokers

    Science.gov (United States)

    Friedel, Jonathan E.; DeHart, William B.; Frye, Charles C. J.; Rung, Jillian M.; Odum, Amy L.

    2016-01-01

    In delay discounting, temporally remote outcomes have less value. Cigarette smoking is associated with steeper discounting of money and consumable outcomes. It is presently unclear whether smokers discount health outcomes more than non-smokers. We sought to establish the generality of steep discounting for different types of health outcomes in cigarette smokers. Seventy participants (38 smokers and 32 non-smokers) completed four hypothetical outcome delay-discounting tasks: a gain of $500, a loss of $500, a temporary boost in health, and temporary cure from a debilitating disease. Participants reported the duration of each health outcome that would be equivalent to $500; these durations were then used in the respective discounting tasks. Delays ranged from 1 week to 25 years. Smokers’ indifference points for monetary gains, boosts in health, and temporary cures were lower than indifference points from non-smokers. Indifference points of one outcome were correlated with indifference points of other outcomes. Smokers demonstrate steeper discounting across a range of delayed outcomes. How a person discounts one outcome predicts how they will discount other outcomes. These two findings support our assertion that delay discounting is in part a trait. PMID:26691848

  10. Changing Delay Discounting in the Light of the Competing Neurobehavioral Decision Systems Theory: A Review

    Science.gov (United States)

    Koffarnus, Mikhail N.; Jarmolowicz, David P.; Mueller, E. Terry; Bickel, Warren K.

    2013-01-01

    Excessively devaluing delayed reinforcers co-occurs with a wide variety of clinical conditions such as drug dependence, obesity, and excessive gambling. If excessive delay discounting is a trans-disease process that underlies the choice behavior leading to these and other negative health conditions, efforts to change an individual's discount rate…

  11. A random utility model of delay discounting and its application to people with externalizing psychopathology.

    Science.gov (United States)

    Dai, Junyi; Gunn, Rachel L; Gerst, Kyle R; Busemeyer, Jerome R; Finn, Peter R

    2016-10-01

    Previous studies have demonstrated that working memory capacity plays a central role in delay discounting in people with externalizing psychopathology. These studies used a hyperbolic discounting model, and its single parameter-a measure of delay discounting-was estimated using the standard method of searching for indifference points between intertemporal options. However, there are several problems with this approach. First, the deterministic perspective on delay discounting underlying the indifference point method might be inappropriate. Second, the estimation procedure using the R2 measure often leads to poor model fit. Third, when parameters are estimated using indifference points only, much of the information collected in a delay discounting decision task is wasted. To overcome these problems, this article proposes a random utility model of delay discounting. The proposed model has 2 parameters, 1 for delay discounting and 1 for choice variability. It was fit to choice data obtained from a recently published data set using both maximum-likelihood and Bayesian parameter estimation. As in previous studies, the delay discounting parameter was significantly associated with both externalizing problems and working memory capacity. Furthermore, choice variability was also found to be significantly associated with both variables. This finding suggests that randomness in decisions may be a mechanism by which externalizing problems and low working memory capacity are associated with poor decision making. The random utility model thus has the advantage of disclosing the role of choice variability, which had been masked by the traditional deterministic model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  12. Decision processes in choice overload: a product of delay and probability discounting?

    Science.gov (United States)

    Kaplan, Brent A; Reed, Derek D

    2013-07-01

    Recent research in the behavioral decision making literature has demonstrated that humans hyperbolically discount the subjective value of options as the number of options increases (Reed et al., 2012). These findings provide a cognitive-behavioral synthesis of the "choice overload" phenomenon, also known as the "paradox of choice." Specifically, these findings suggest that temporal discounting may serve as the underlying process contributing to this effect. As an extension, this study examined the effects of reward magnitude sizes had on rates temporal and options discounting. This manipulation was conducted to determine what role temporal discounting plays in discounting of options. The present results suggest that temporal discounting may not be the only process contributing to the choice overload effect. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Changing delay discounting in the light of the competing neurobehavioral decision systems theory: a review.

    Science.gov (United States)

    Koffarnus, Mikhail N; Jarmolowicz, David P; Mueller, E Terry; Bickel, Warren K

    2013-01-01

    Excessively devaluing delayed reinforcers co-occurs with a wide variety of clinical conditions such as drug dependence, obesity, and excessive gambling. If excessive delay discounting is a trans-disease process that underlies the choice behavior leading to these and other negative health conditions, efforts to change an individual's discount rate are arguably important. Although discount rate is often regarded as a relatively stable trait, descriptions of interventions and environmental manipulations that successfully alter discount rate have begun to appear in the literature. In this review, we compare published examples of procedures that change discount rate and classify them into categories of procedures, including therapeutic interventions, direct manipulation of the executive decision-making system, framing effects, physiological state effects, and acute drug effects. These changes in discount rate are interpreted from the perspective of the competing neurobehavioral decision systems theory, which describes a combination of neurological and behavioral processes that account for delay discounting. We also suggest future directions that researchers could take to identify the mechanistic processes that allow for changes in discount rate and to test whether the competing neurobehavioral decision systems view of delay discounting is correct. © Society for the Experimental Analysis of Behavior.

  14. Delay and probability discounting of sexual and monetary outcomes in individuals with cocaine use disorders and matched controls.

    Science.gov (United States)

    Johnson, Matthew W; Johnson, Patrick S; Herrmann, Evan S; Sweeney, Mary M

    2015-01-01

    Individuals with cocaine use disorders are disproportionately affected by HIV/AIDS, partly due to higher rates of unprotected sex. Recent research suggests delay discounting of condom use is a factor in sexual HIV risk. Delay discounting is a behavioral economic concept describing how delaying an event reduces that event's value or impact on behavior. Probability discounting is a related concept describing how the uncertainty of an event decreases its impact on behavior. Individuals with cocaine use disorders (n = 23) and matched non-cocaine-using controls (n = 24) were compared in decision-making tasks involving hypothetical outcomes: delay discounting of condom-protected sex (Sexual Delay Discounting Task), delay discounting of money, the effect of sexually transmitted infection (STI) risk on likelihood of condom use (Sexual Probability Discounting Task), and probability discounting of money. The Cocaine group discounted delayed condom-protected sex (i.e., were more likely to have unprotected sex vs. wait for a condom) significantly more than controls in two of four Sexual Delay Discounting Task partner conditions. The Cocaine group also discounted delayed money (i.e., preferred smaller immediate amounts over larger delayed amounts) significantly more than controls. In the Sexual Probability Discounting Task, both groups showed sensitivity to STI risk, however the groups did not differ. The Cocaine group did not consistently discount probabilistic money more or less than controls. Steeper discounting of delayed, but not probabilistic, sexual outcomes may contribute to greater rates of sexual HIV risk among individuals with cocaine use disorders. Probability discounting of sexual outcomes may contribute to risk of unprotected sex in both groups. Correlations showed sexual and monetary results were unrelated, for both delay and probability discounting. The results highlight the importance of studying specific behavioral processes (e.g., delay and probability

  15. Delay and probability discounting of sexual and monetary outcomes in individuals with cocaine use disorders and matched controls.

    Directory of Open Access Journals (Sweden)

    Matthew W Johnson

    Full Text Available Individuals with cocaine use disorders are disproportionately affected by HIV/AIDS, partly due to higher rates of unprotected sex. Recent research suggests delay discounting of condom use is a factor in sexual HIV risk. Delay discounting is a behavioral economic concept describing how delaying an event reduces that event's value or impact on behavior. Probability discounting is a related concept describing how the uncertainty of an event decreases its impact on behavior. Individuals with cocaine use disorders (n = 23 and matched non-cocaine-using controls (n = 24 were compared in decision-making tasks involving hypothetical outcomes: delay discounting of condom-protected sex (Sexual Delay Discounting Task, delay discounting of money, the effect of sexually transmitted infection (STI risk on likelihood of condom use (Sexual Probability Discounting Task, and probability discounting of money. The Cocaine group discounted delayed condom-protected sex (i.e., were more likely to have unprotected sex vs. wait for a condom significantly more than controls in two of four Sexual Delay Discounting Task partner conditions. The Cocaine group also discounted delayed money (i.e., preferred smaller immediate amounts over larger delayed amounts significantly more than controls. In the Sexual Probability Discounting Task, both groups showed sensitivity to STI risk, however the groups did not differ. The Cocaine group did not consistently discount probabilistic money more or less than controls. Steeper discounting of delayed, but not probabilistic, sexual outcomes may contribute to greater rates of sexual HIV risk among individuals with cocaine use disorders. Probability discounting of sexual outcomes may contribute to risk of unprotected sex in both groups. Correlations showed sexual and monetary results were unrelated, for both delay and probability discounting. The results highlight the importance of studying specific behavioral processes (e.g., delay and

  16. Delay discounting, self-control, and substance use among adult drug court participants.

    Science.gov (United States)

    Jones, Craig G A; Fearnley, Helen; Panagiotopoulos, Barbara; Kemp, Richard I

    2015-08-01

    The current study examined the relationship between two measures of impulsiveness and the odds of substance use among a sample of participants on an Australian drug court (n=80). Participants completed a computer-based delay discounting task, a paper-based delay discounting task, and a questionnaire-based measure of self-control. The delay discounting tasks measured individual differences in the value attributed to distal outcomes, which is one aspect of impulsive behavior that has been found to be over-represented among illicit drug users. The relationship between the measures of impulsiveness and the odds of substance use was assessed by fitting longitudinal panel regression models with adjustment for informative treatment dropout. Consistent with previous research, drug court participants were found to have higher discount rates (i.e. were more impulsive) than a noncriminal population of university students (n=101). Drug court participants also discounted delayed gains more than delayed losses. Delay discounting was not significantly associated with the odds of substance use on the drug court program. There was a positive relationship between the survey-based measure of impulsivity and the mean substance use frequency. The authors conclude that impulsivity is correlated with substance use among drug court participants but not when measuring impulsivity using a delay discounting paradigm.

  17. Discounting

    International Nuclear Information System (INIS)

    Jones, P.M.S.

    1987-01-01

    Discounting is a procedure used to facilitate comparison of investment options where either or both the investment and income are spread out in time. It is based on the observation that under most circumstances a sum of money in the hand is worth more to the holder than the same sum in real terms in the future, because the holder can use the money in the intervening time. As discounting is used widely in economic assessment it is valid to use it for assessing electricity generation by nuclear power or fuel cycle costs. The way in which discounting works is explained, including factors such as risk and non-monetary aspects. The rate of the discount is a matter of government policy. In the United Kingdom it is currently (1986) 5 percent per annum for projects such as hospitals and road building. There is no good reason for this to be different for energy projects. (U.K.)

  18. Examination of a recommended algorithm for eliminating nonsystematic delay discounting response sets.

    Science.gov (United States)

    White, Thomas J; Redner, Ryan; Skelly, Joan M; Higgins, Stephen T

    2015-09-01

    To examine (1) whether use of a recommended algorithm (Johnson and Bickel, 2008) improves upon conventional statistical model fit (R(2)) for identifying nonsystematic response sets in delay discounting (DD) data, (2) whether removing such data meaningfully effects research outcomes, and (3) to identify participant characteristics associated with nonsystematic response sets. Discounting of hypothetical monetary rewards was assessed among 349 pregnant women (231 smokers and 118 recent quitters) via a computerized task comparing $1000 at seven future time points with smaller values available immediately. Nonsystematic response sets were identified using the algorithm and conventional statistical model fit (R(2)). The association between DD and quitting was analyzed with and without nonsystematic response sets to examine whether the inclusion or exclusion impacts this relationship. Logistic regression was used to examine whether participant sociodemographics were associated with nonsystematic response sets. The algorithm excluded fewer cases than the R(2) method (14% vs. 16%), and was not correlated with logk as is R(2). The relationship between logk and the clinical outcome (spontaneous quitting) was unaffected by exclusion methods; however, other variables in the model were affected. Lower educational attainment and younger age were associated with nonsystematic response sets. The algorithm eliminated data that were inconsistent with the nature of discounting and retained data that were orderly. Neither method impacted the smoking/DD relationship in this data set. Nonsystematic response sets are more likely among younger and less educated participants, who may need extra training or support in DD studies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Reward acts as a signal to control delay-period activity in delayed-response tasks.

    Science.gov (United States)

    Ichihara-Takeda, Satoe; Takeda, Kazuyoshi; Funahashi, Shintaro

    2010-03-31

    Prefrontal delay-period activity represents a neural mechanism for the active maintenance of information and needs to be controlled by some signal to appropriately operate working memory. To examine whether reward-delivery acts as this signal, the effects of delay-period activity in response to unexpected reward-delivery were examined by analyzing single-neuron activity recorded in the primate dorsolateral prefrontal cortex. Among neurons that showed delay-period activity, 34% showed inhibition of this activity in response to unexpected reward-delivery. The delay-period activity of these neurons was affected by the expectation of reward-delivery. The strength of the reward signal in controlling the delay-period activity is related to the strength of the effect of reward information on the delay-period activity. These results indicate that reward-delivery acts as a signal to control delay-period activity.

  20. An alternative approach to calculating Area-Under-the-Curve (AUC) in delay discounting research.

    Science.gov (United States)

    Borges, Allison M; Kuang, Jinyi; Milhorn, Hannah; Yi, Richard

    2016-09-01

    Applied to delay discounting data, Area-Under-the-Curve (AUC) provides an atheoretical index of the rate of delay discounting. The conventional method of calculating AUC, by summing the areas of the trapezoids formed by successive delay-indifference point pairings, does not account for the fact that most delay discounting tasks scale delay pseudoexponentially, that is, time intervals between delays typically get larger as delays get longer. This results in a disproportionate contribution of indifference points at long delays to the total AUC, with minimal contribution from indifference points at short delays. We propose two modifications that correct for this imbalance via a base-10 logarithmic transformation and an ordinal scaling transformation of delays. These newly proposed indices of discounting, AUClog d and AUCor d, address the limitation of AUC while preserving a primary strength (remaining atheoretical). Re-examination of previously published data provides empirical support for both AUClog d and AUCor d . Thus, we believe theoretical and empirical arguments favor these methods as the preferred atheoretical indices of delay discounting. © 2016 Society for the Experimental Analysis of Behavior.

  1. Delay discounting and intake of ready-to-eat and away-from-home foods in overweight and obese women

    OpenAIRE

    Appelhans, Bradley M.; Waring, Molly E.; Schneider, Kristin L.; Pagoto, Sherry L.; DeBiasse, Michelle A.; Whited, Matthew C.; Lynch, Elizabeth B.

    2012-01-01

    A shift from home-prepared to away-from-home and ready-to-eat foods has occurred in recent decades, which has implications for obesity and health. This study tested whether delay discounting, a facet of impulsivity reflecting sensitivity to immediate reward, is associated with the frequency of consumption and typical amount consumed of home-prepared, away-from-home, and ready-to-eat foods among overweight and obese women. Seventy-eight participants completed a binary choice task assessing dis...

  2. Impulsive aggression, delay discounting, and adolescent suicide attempts: effects of current psychotropic medication use and family history of suicidal behavior.

    Science.gov (United States)

    Bridge, Jeffrey A; Reynolds, Brady; McBee-Strayer, Sandra M; Sheftall, Arielle H; Ackerman, John; Stevens, Jack; Mendoza, Kristen; Campo, John V; Brent, David A

    2015-03-01

    Impulsive-aggressive behaviors have been consistently implicated in the phenomenology, neurobiology, and familial aggregation of suicidal behavior. The purpose of this study was to extend previous work by examining laboratory behavioral measures of delayed reward impulsivity and impulsive aggression in adolescent suicide attempters and never-suicidal comparison subjects. Using the Point Subtraction Aggression Paradigm (PSAP) and the Delay Discounting Task (DDQ), the authors examined delay discounting and impulsive aggression in 40 adolescent suicide attempters, ages 13-18, and 40 never-suicidal, demographically matched psychiatric comparison subjects. Overall, suicide attempters and comparison subjects performed similarly on the PSAP and DDQ. There was a significant group by current psychotropic medication use interaction (p=0.013) for mean aggressive responses on the PSAP. Group comparisons revealed that attempters emitted more aggressive responses per provocation than comparison subjects, only in those not on psychotropic medication (p=0.049), whereas for those currently treated with psychotropic medication, there were no group differences (p>0.05). This interaction effect was specific to current antidepressant use. Among all subjects, family history of suicidal behavior (suicide or suicide attempt) in first degree relatives was significantly correlated with both delay discounting (r=-0.22, p=0.049), and aggressive responding (r=0.27, p=0.015). Family history of suicidal behavior was associated with delay discounting, but not with aggressive responding on the PSAP, after controlling for relevant covariates. In this study, impulsive-aggressive responding was associated with suicide attempt only in those not being treated with antidepressants. Future work to replicate and extend these findings could have important therapeutic implications for the treatment of depressed suicide attempters, many of whom are affected by impulsive aggression.

  3. Dysfunctional Prefrontal Function Is Associated with Impulsivity in People with Internet Gaming Disorder during a Delay Discounting Task

    Directory of Open Access Journals (Sweden)

    Yifan Wang

    2017-12-01

    Full Text Available Internet gaming disorder (IGD, defined as the persistent use of online games with ignorance of adverse consequences, has increasingly raised widespread public concerns. This study aimed at elucidating the precise mechanisms underlying IGD by comparing intertemporal decision-making process between 18 IGD participants and 21 matched healthy controls (HCs. Both behavioral and fMRI data were recorded from a delay discounting task. At the behavioral level, the IGD showed a higher discount rate k than HC; and in IGD group, both the reaction time (delay − immediate and the discount rate k were significantly positively correlated with the severity of IGD. At the neural level, the IGD exhibited reduced brain activations in the dorsolateral prefrontal cortex and bilateral inferior frontal gyrus compared to HC during performing delay trials relative to immediate ones. Taken together, the results suggested that IGD showed deficits in making decisions and tended to pursuit immediate satisfaction. The underlying mechanism arises from the deficient ability in evaluating between delayed reward and immediate satisfaction, and the impaired ability in impulse inhibition, which may be associated with the dysfunction of the prefrontal activation. These might be the reason why IGD continue playing online games in spite of facing severe negative consequences.

  4. Dysfunctional Prefrontal Function Is Associated with Impulsivity in People with Internet Gaming Disorder during a Delay Discounting Task.

    Science.gov (United States)

    Wang, Yifan; Hu, Yanbo; Xu, Jiaojing; Zhou, Hongli; Lin, Xiao; Du, Xiaoxia; Dong, Guangheng

    2017-01-01

    Internet gaming disorder (IGD), defined as the persistent use of online games with ignorance of adverse consequences, has increasingly raised widespread public concerns. This study aimed at elucidating the precise mechanisms underlying IGD by comparing intertemporal decision-making process between 18 IGD participants and 21 matched healthy controls (HCs). Both behavioral and fMRI data were recorded from a delay discounting task. At the behavioral level, the IGD showed a higher discount rate k than HC; and in IGD group, both the reaction time (delay - immediate) and the discount rate k were significantly positively correlated with the severity of IGD. At the neural level, the IGD exhibited reduced brain activations in the dorsolateral prefrontal cortex and bilateral inferior frontal gyrus compared to HC during performing delay trials relative to immediate ones. Taken together, the results suggested that IGD showed deficits in making decisions and tended to pursuit immediate satisfaction. The underlying mechanism arises from the deficient ability in evaluating between delayed reward and immediate satisfaction, and the impaired ability in impulse inhibition, which may be associated with the dysfunction of the prefrontal activation. These might be the reason why IGD continue playing online games in spite of facing severe negative consequences.

  5. Testing the Reliability of Delay Discounting of Ten Commodities Using the Fill-in-the-Blank Method

    Science.gov (United States)

    Weatherly, Jeffrey N.; Derenne, Adam; Terrell, Heather K.

    2011-01-01

    Several measures of delay discounting have been shown to be reliable over periods of up to 3 months. In the present study, 115 participants completed a fill-in-the-blank (FITB) delay-discounting task on sets of 5 different commodities, 12 weeks apart. Results showed that discounting rates were not well described by a hyperbolic function but were…

  6. A Job with a Future? Delay Discounting, Magnitude Effects, and Domain Independence of Utility for Career Decisions.

    Science.gov (United States)

    Schoenfelder, Thomas E.; Hantula, Donald A.

    2003-01-01

    Seniors (n=20) assessed two job offers with differences in domain (salary/tasks), delay (career-long earnings), and magnitude (initial salary offer). Contrary to discounted utility theory, choices reflected nonconstant discount rates for future salary/tasks (delay effect), lower discount rates for salary/preferred tasks (magnitude effect), and a…

  7. High-sucrose diets in male rats disrupt aspects of decision making tasks, motivation and spatial memory, but not impulsivity measured by operant delay-discounting.

    Science.gov (United States)

    Wong, Alanna; Dogra, Vimi R; Reichelt, Amy C

    2017-06-01

    Excessive consumption of sugar sweetened drinks is proposed to produce functional changes in the hippocampus and prefrontal cortex, leading to perturbations in behavioural control. Impairments in behavioural control have been observed in obese people on tasks that involve making choices, including delay-discounting, indicative of increased impulsivity. In this study we examined the impact of 2h daily access to 10% sucrose (or no sucrose in controls) in young male rats on behavioural tasks reliant on hippocampal function including delay-discounting, T-maze forced choice alternation and place recognition memory, as well as progressive ratio to measure motivation. We observed deficits in place recognition memory and T-maze forced choice alternation, indicative of hippocampal deficits in rats with a history of sucrose consumption. Moreover, rats with a history of sucrose consumption were less motivated to lever press for rewards on a progressive ratio schedule. However, rats with a history of sucrose consumption performed equally to control animals during the delay-discounting task, suggesting that they discounted for reward size over a delay in a manner comparable to control animals. These findings indicate that high-sucrose diets impact on spatial and working memory processes, but do not induce impulsive-like choice behaviours in rats, suggesting that unhealthy diet choices may not influence this aspect of decision-making behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Delay discounting and intake of ready-to-eat and away-from-home foods in overweight and obese women.

    Science.gov (United States)

    Appelhans, Bradley M; Waring, Molly E; Schneider, Kristin L; Pagoto, Sherry L; DeBiasse, Michelle A; Debiasse, Michelle A; Whited, Matthew C; Lynch, Elizabeth B

    2012-10-01

    A shift from home-prepared to away-from-home and ready-to-eat foods has occurred in recent decades, which has implications for obesity and health. This study tested whether delay discounting, a facet of impulsivity reflecting sensitivity to immediate reward, is associated with the frequency of consumption and typical amount consumed of home-prepared, away-from-home, and ready-to-eat foods among overweight and obese women. Seventy-eight participants completed a binary choice task assessing discounting of delayed monetary rewards. Nutrient analysis of weighed food records characterized dietary intake over seven consecutive days. Foods were categorized as home-prepared, away-from-home, or ready-to-eat by a registered dietitian from information provided by participants. Delay discounting was not associated with the frequency of consuming home-prepared, away-from-home, and ready-to-eat foods as reflected in the percentages of recorded foods or total energy intake from each category. However, once consuming away-from-home and ready-to-eat foods (but not home-prepared foods), impulsive women consumed more energy than less impulsive women. Exploratory analyses indicated that more impulsive women chose away-from-home foods with a higher energy density (kcal/g). Impulsivity was associated with the quantity of away-from-home and ready-to-eat foods consumed, but not the frequency of their consumption. Home food preparation may be critical to weight control for impulsive individuals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Decline of prefrontal cortical-mediated executive functions but attenuated delay discounting in aged Fischer 344 × brown Norway hybrid rats.

    Science.gov (United States)

    Hernandez, Caesar M; Vetere, Lauren M; Orsini, Caitlin A; McQuail, Joseph A; Maurer, Andrew P; Burke, Sara N; Setlow, Barry; Bizon, Jennifer L

    2017-12-01

    Despite the fact that prefrontal cortex (PFC) function declines with age, aged individuals generally show an enhanced ability to delay gratification, as evident by less discounting of delayed rewards in intertemporal choice tasks. The present study was designed to evaluate relationships between 2 aspects of PFC-dependent cognition (working memory and cognitive flexibility) and intertemporal choice in young (6 months) and aged (24 months) Fischer 344 × brown Norway F1 hybrid rats. Rats were also evaluated for motivation to earn rewards using a progressive ratio task. As previously reported, aged rats showed attenuated discounting of delayed rewards, impaired working memory, and impaired cognitive flexibility compared with young. Among aged rats, greater choice of delayed reward was associated with preserved working memory, impaired cognitive flexibility, and less motivation to work for food. These relationships suggest that age-related changes in PFC and incentive motivation contribute to variance in intertemporal choice within the aged population. Cognitive impairments mediated by PFC are unlikely, however, to fully account for the enhanced ability to delay gratification that accompanies aging. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Shallow discounting of delayed cocaine by male rhesus monkeys when immediate food is the choice alternative.

    Science.gov (United States)

    Huskinson, Sally L; Myerson, Joel; Green, Leonard; Rowlett, James K; Woolverton, William L; Freeman, Kevin B

    2016-12-01

    Huskinson et al. (2015) recently examined delay discounting in monkeys choosing between an immediate drug (cocaine) reinforcer and a delayed nondrug (food) reinforcer. The present experiment examined the reverse situation: choice between immediate nondrug (food) and delayed drug (cocaine) reinforcers. Whereas the former choice situation exemplifies drug abuse from a delay-discounting perspective, our interest in the latter choice situation is derived from the observation that drug abusers, who characteristically are associated with impulsive choice, typically must devote considerable time to procuring drugs, often at the expense of immediate nondrug alternatives. Accordingly, we analyzed 3 male rhesus monkeys' choices between immediate food and delayed cocaine (0.1 and 0.2 mg/kg/injection) using a hyperbolic model that allowed us to compare discounting rates between qualitatively different reinforcers. Choice of immediate food increased with food amount, and choice functions generally shifted leftward as delay to cocaine increased, indicating a decrease in the subjective value of cocaine. Compared with our previous delay-discounting experiment with immediate cocaine versus delayed food, both doses of delayed cocaine were discounted at a shallow rate. The present results demonstrate that rhesus monkeys will tolerate relatively long delays in an immediate-food versus delayed-drug situation, suggesting that in intertemporal choices between cocaine and food, the subjective value of cocaine is less affected by the delay until reinforcement than is the subjective value of delayed food. More generally, the present findings suggest that although drug abusers may choose impulsively when immediate drug reinforcement is available, they exercise self-control in the acquisition of a highly preferred, delayed drug reinforcer. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective

    Directory of Open Access Journals (Sweden)

    Lars M. Göllner

    2018-01-01

    Full Text Available The delay of gratification (DoG in children is widely investigated with an experimental procedure originally called the “marshmallow test,” whereas the studies on self-regulation (SR in adolescents and adults usually use self-report questionnaires. Delay discounting (DD measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP and episodic future thinking (EFT] as well as age differences in these constructs. Participants from five age groups (9–14, 18–25, 35–55, 65–80, 80+ participated in the study (N = 96. While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification.

  12. Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective.

    Science.gov (United States)

    Göllner, Lars M; Ballhausen, Nicola; Kliegel, Matthias; Forstmeier, Simon

    2017-01-01

    The delay of gratification (DoG) in children is widely investigated with an experimental procedure originally called the "marshmallow test," whereas the studies on self-regulation (SR) in adolescents and adults usually use self-report questionnaires. Delay discounting (DD) measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP) and episodic future thinking (EFT)] as well as age differences in these constructs. Participants from five age groups (9-14, 18-25, 35-55, 65-80, 80+) participated in the study ( N = 96). While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC) was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest) in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification.

  13. Cross-cultural comparisons of delay discounting of gain and loss.

    Science.gov (United States)

    Ishii, Keiko; Gang, Lili; Takahashi, Taiki

    2016-11-01

    People generally tend to discount future outcomes in favor of smaller but immediate gains (i.e., delay discounting). The present research examined cultural similarities and differences in delay discounting of gain and loss between Chinese and Japanese, based on a q-exponential model of intertemporal choice. Using a hypothetical situation, we asked 65 Japanese participants and 51 Chinese participants to choose between receiving (or paying) a different amount of money immediately or with a specified delay (1 week, 2 weeks, 1 month, 6 months, 1 year, 5 years, and 25 years). For each delay, participants completed a series of 40 binary choices for gain or loss. Regardless of cultures, the q-exponential model was the optimal model. Both impulsivity and time-inconsistency were higher for future gains than for future losses. In addition to the cultural similarities, Chinese participants discounted future gains and losses more steeply than did Japanese. In contrast, Japanese participants were more time-inconsistent in delay discounting than were Chinese, suggesting that the reduction in their subjective value depended relatively on delay.

  14. Wait for It: Delay-Discounting and Academic Performance among an Irish Adolescent Sample

    Science.gov (United States)

    Freeney, Yseult; O'Connell, Michael

    2010-01-01

    Beyond cognitive ability and family background, are there other significant determinants of educational attainment? From research in psychology, economics, education and criminology, one powerful influence is the ability to delay gratification, operationalised in this paper as "delay-discounting". It is intuitively plausible that the…

  15. The association between cingulate cortex glutamate concentration and delay discounting is mediated by resting state functional connectivity

    NARCIS (Netherlands)

    Schmaal, L.; Goudriaan, A.E.; van der Meer, J.; van den Brink, W.; Veltman, D.J.

    2012-01-01

    Humans vary in their ability to delay gratification and impulsive decision making is a common feature in various psychiatric disorders. The level of delay discounting is a relatively stable psychological trait, and therefore neural processes implicated in delay discounting are likely to be based on

  16. Effects of blood glucose on delay discounting, food intake and counterregulation in lean and obese men.

    Science.gov (United States)

    Klement, Johanna; Kubera, Britta; Eggeling, Jonas; Rädel, Christin; Wagner, Christin; Park, Soyoung Q; Peters, Achim

    2018-03-01

    Delay discounting as a measure of impulsivity has been shown to be higher in obesity with an association of increased food intake. Moreover, obese humans showed a higher wanting for high-calorie food than lean men when blood glucose concentrations were low. First studies linking blood glucose levels to delay discounting yielded mixed results. We hypothesized that obese people - in comparison to lean men - have a relative lack of energy, especially when blood glucose levels are low, that results in higher levels of delay discounting, food intake and hormonal counterregulation. We investigated 20 lean and 20 obese healthy young men in a single-blind balanced cross-over design. With a standardized glucose clamp technique, subjects underwent a hypoglycemic state in one condition and a euglycemic state in the control condition. Regularly, blood was sampled for assessment of hormonal status, and questionnaires were filled out to assess delay discounting and symptom awareness. After normalizing blood glucose concentrations, subjects were free to eat from a standardized test buffet, followed by a snack test. Delay discounting was higher in obese than in lean men throughout experiments (p  0.1). Furthermore, the discounting performance did not correlate with food intake from the test buffet or snack test (p > 0.3). As a response to hypoglycemia, hormonal counterregulation was pronounced in both weight groups (p  0.5). Our data suggest that augmented delay discounting is a robust feature in obesity that is not linked to glucose levels or actual food intake. With our systematically controlled approach, combining performance in delay discounting with regard to distinct blood glucose levels, different weight groups, counterregulatory behavior and food intake, our results imply that delay discounting is not susceptible to fluctuations of blood glucose and do not support the assumption that a low body's energy content leads to increased impulsivity. Further

  17. Longitudinal Associations Among Religiousness, Delay Discounting, and Substance Use Initiation in Early Adolescence.

    Science.gov (United States)

    Kim-Spoon, Jungmeen; McCullough, Michael E; Bickel, W K; Farley, Julee P; Longo, Gregory S

    2015-03-01

    Prior research indicates that religiousness is related negatively to adolescent health risk behaviors, yet how such protective effects operate is not well understood. This study examined the longitudinal associations among organizational and personal religiousness, delay discounting, and substance use initiation (alcohol, cigarette, and marijuana use). The sample comprised 106 early adolescents (10-13 years of age, 52% female) who were not using substances at Time 1. Path analyses suggested that high levels of personal religiousness at Time 1 were related to low levels of substance use at Time 2 (2.4 years later), mediated by low levels of delay discounting. Delay discounting appears to be an important contributor to the protective effect of religiousness on the development of substance use among adolescents.

  18. Heroin delay discounting: Modulation by pharmacological state, drug-use impulsivity, and intelligence.

    Science.gov (United States)

    Stoltman, Jonathan J K; Woodcock, Eric A; Lister, Jamey J; Lundahl, Leslie H; Greenwald, Mark K

    2015-12-01

    Delay discounting (DD) refers to how rapidly an individual devalues goods based on delays to receipt. DD usually is considered a trait variable but can be state dependent, yet few studies have assessed commodity valuation at short, naturalistically relevant time intervals that might enable state-dependent analysis. This study aimed to determine whether drug-use impulsivity and intelligence influence heroin DD at short (ecologically relevant) delays during two pharmacological states (heroin satiation and withdrawal). Out-of-treatment, intensive heroin users (n = 170; 53.5% African American; 66.7% male) provided complete DD data during imagined heroin satiation and withdrawal. Delays were 3, 6, 12, 24, 48, 72, and 96 hours; maximum delayed heroin amount was thirty $10 bags. Indifference points were used to calculate area under the curve (AUC). We also assessed drug-use impulsivity (subscales from the Impulsive Relapse Questionnaire [IRQ]) and estimated intelligence (Shipley IQ) as predictors of DD. Heroin discounting was greater (smaller AUC) during withdrawal than satiation. In regression analyses, lower intelligence and IRQ Capacity for Delay as well as higher IRQ Speed (to return to drug use) predicted greater heroin discounting in the satiation condition. Lower intelligence and higher IRQ Speed predicted greater discounting in the withdrawal condition. Sex, race, substance use variables, and other IRQ subscales were not significantly related to the withdrawal or satiation DD behavior. In summary, heroin discounting was temporally rapid, pharmacologically state dependent, and predicted by drug-use impulsivity and estimated intelligence. These findings highlight a novel and sensitive measure of acute DD that is easy to administer. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  19. Resource Slack and Propensity to Discount Delayed Investments of Time Versus Money

    Science.gov (United States)

    Zauberman, Gal; Lynch, John G.

    2005-01-01

    The authors demonstrate that people discount delayed outcomes as a result of perceived changes over time in supplies of slack. Slack is the perceived surplus of a given resource available to complete a focal task. The present research shows that, in general, people expect slack for time to be greater in the future than in the present. Typically,…

  20. Intolerance to Delayed Reward in Girls with Multiple Suicide Attempts

    Science.gov (United States)

    Mathias, Charles W.; Dougherty, Donald M.; James, Lisa M.; Richard, Dawn M.; Dawes, Michael A.; Acheson, Ashley; Hill-Kapturczak, Nathalie

    2011-01-01

    Impulsivity has been conceptualized as influencing the expression of suicidal behavior. Adolescence is a developmental period characterized both by a relatively high rate of suicide attempts and a high level of impulsivity. The current study examined two behavioral measures (delay reward and disinhibition) and one self-report measure of…

  1. The effect of reinforcer magnitude on probability and delay discounting of experienced outcomes in a computer game task in humans.

    Science.gov (United States)

    Greenhow, Anna K; Hunt, Maree J; Macaskill, Anne C; Harper, David N

    2015-09-01

    Delay and uncertainty of receipt both reduce the subjective value of reinforcers. Delay has a greater impact on the subjective value of smaller reinforcers than of larger ones while the reverse is true for uncertainty. We investigated the effect of reinforcer magnitude on discounting of delayed and uncertain reinforcers using a novel approach: embedding relevant choices within a computer game. Participants made repeated choices between smaller, certain, immediate outcomes and larger, but delayed or uncertain outcomes while experiencing the result of each choice. Participants' choices were generally well described by the hyperbolic discounting function. Smaller numbers of points were discounted more steeply than larger numbers as a function of delay but not probability. The novel experiential choice task described is a promising approach to investigating both delay and probability discounting in humans. © Society for the Experimental Analysis of Behavior.

  2. Delay Discounting as an Index of Sustainable Behavior: Devaluation of Future Air Quality and Implications for Public Health.

    Science.gov (United States)

    Berry, Meredith S; Nickerson, Norma P; Odum, Amy L

    2017-09-01

    Poor air quality and resulting annual deaths represent significant public health concerns. Recently, rapid delay discounting (the devaluation of future outcomes) of air quality has been considered a potential barrier for engaging in long term, sustainable behaviors that might help to reduce emissions (e.g., reducing private car use, societal support for clean air initiatives). Delay discounting has been shown to be predictive of real world behavior outside of laboratory settings, and therefore may offer an important framework beyond traditional variables thought to measure sustainable behavior such as importance of an environmental issue, or environmental attitudes/values, although more research is needed in this area. We examined relations between discounting of air quality, respiratory health, and monetary gains and losses. We also examined, relations between discounting and self-reported importance of air quality and respiratory health, and nature relatedness. Results showed rapid delay discounting of all outcomes across the time frames assessed, and significant positive correlations between delay discounting of air quality, respiratory health, and monetary outcomes. Steeper discounting of monetary outcomes relative to air quality and respiratory health outcomes was observed in the context of gains; however, no differences in discounting were observed across losses of monetary, air quality, and respiratory health. Replicating the sign effect, monetary outcomes were discounted more steeply than monetary losses. Importance of air quality, respiratory health and nature relatedness were significantly and positively correlated with one another, but not with degree of delay discounting of any outcome, demonstrating the need for more comprehensive measures that predict pro-environmental behaviors that might benefit individuals and public health over time. These results add to our understanding of decision-making, and demonstrate alarming rates of delay discounting of

  3. Delay Discounting of Video Game Players: Comparison of Time Duration Among Gamers.

    Science.gov (United States)

    Buono, Frank D; Sprong, Matthew E; Lloyd, Daniel P; Cutter, Christopher J; Printz, Destiny M B; Sullivan, Ryan M; Moore, Brent A

    2017-02-01

    Video game addiction or Internet game disorder, as proposed by the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), has similar criterion characteristics to other impulse control disorders. There is limited research examining video game addiction within a behavioral economic framework using delay discounting. The current study evaluated delay-discounting patterns of money and video game play by usual weekly hours of video game play. A total of 104 participants were split into 1 of 3 groups of video game players (low, medium, and high) and were asked to complete a monetary and video game discounting procedure through an online survey. Results showed significant differences between groups within both the monetary (p = 0.003) and video game discounting procedures (p = 0.004). Additionally, a positive linear relationship was noted between the groups across both procedures. The results of the current article reinforce previous findings that more hours of video game use are associated with greater impulsivity and provide implications for future research.

  4. A Tutorial on the Use of Excel 2010 and Excel for Mac 2011 for Conducting Delay-Discounting Analyses

    Science.gov (United States)

    Reed, Derek D.; Kaplan, Brent A.; Brewer, Adam T.

    2012-01-01

    In recent years, researchers and practitioners in the behavioral sciences have profited from a growing literature on delay discounting. The purpose of this article is to provide readers with a brief tutorial on how to use Microsoft Office Excel 2010 and Excel for Mac 2011 to analyze discounting data to yield parameters for both the hyperbolic…

  5. Explicit information reduces discounting behavior in monkeys

    Directory of Open Access Journals (Sweden)

    John ePearson

    2010-12-01

    Full Text Available Animals are notoriously impulsive in common laboratory experiments, preferring smaller, sooner rewards to larger, delayed rewards even when this reduces average reward rates. By contrast, the same animals often engage in natural behaviors that require extreme patience, such as food caching, stalking prey, and traveling long distances to high quality food sites. One possible explanation for this discrepancy is that standard laboratory delay discounting tasks artificially inflate impulsivity by subverting animals’ common learning strategies. To test this idea, we examined choices made by rhesus macaques in two variants of a standard delay discounting task. In the conventional variant, post-reward delays were uncued and adjusted to render total trial length constant; in the second, all delays were cued explicitly. We found that measured discounting was significantly reduced in the cued task, with discount rates well below those reported in studies using the standard uncued design. When monkeys had complete information, their decisions were more consistent with a strategy of reward rate maximization. These results indicate that monkeys, and perhaps other animals, are more patient than is normally assumed, and that laboratory measures of delay discounting may overstate impulsivity.

  6. Isolating behavioral mechanisms of intertemporal choice: nicotine effects on delay discounting and amount sensitivity.

    Science.gov (United States)

    Locey, Matthew L; Dallery, Jesse

    2009-03-01

    Many drugs of abuse produce changes in impulsive choice, that is, choice for a smaller-sooner reinforcer over a larger-later reinforcer. Because the alternatives differ in both delay and amount, it is not clear whether these drug effects are due to the differences in reinforcer delay or amount. To isolate the effects of delay, we used a titrating delay procedure. In phase 1, 9 rats made discrete choices between variable delays (1 or 19 s, equal probability of each) and a delay to a single food pellet. The computer titrated the delay to a single food pellet until the rats were indifferent between the two options. This indifference delay was used as the starting value for the titrating delay for all future sessions. We next evaluated the acute effects of nicotine (subcutaneous 1.0, 0.3, 0.1, and 0.03 mg/kg) on choice. If nicotine increases delay discounting, it should have increased preference for the variable delay. Instead, nicotine had very little effect on choice. In a second phase, the titrated delay alternative produced three food pellets instead of one, which was again produced by the variable delay (1 s or 19 s) alternative. Under this procedure, nicotine increased preference for the one pellet alternative. Nicotine-induced changes in impulsive choice are therefore likely due to differences in reinforcer amount rather than differences in reinforcer delay. In addition, it may be necessary to include an amount sensitivity parameter in any mathematical model of choice when the alternatives differ in reinforcer amount.

  7. Delay discounting differences in brain activation, connectivity, and structure in individuals with addiction: a systematic review protocol.

    Science.gov (United States)

    Owens, Max M; Amlung, Michael T; Beach, Steven R H; Sweet, Lawrence H; MacKillop, James

    2017-07-11

    Delayed reward discounting (DRD), the degree to which future rewards are discounted relative to immediate rewards, is used as an index of impulsive decision-making and has been associated with a number of problematic health behaviors. Given the robust behavioral association between DRD and addictive behavior, there is an expanding literature investigating the differences in the functional and structural correlates of DRD in the brain between addicted and healthy individuals. However, there has yet to be a systematic review which characterizes differences in regional brain activation, functional connectivity, and structure and places them in the larger context of the DRD literature. The objective of this systematic review is to summarize and critically appraise the existing literature examining differences between addicted and healthy individuals in the neural correlates of DRD using magnetic resonance imaging (MRI) or functional magnetic resonance imaging (fMRI). A systematic search strategy will be implemented that uses Boolean search terms in PubMed/MEDLINE and PsycINFO, as well as manual search methods, to identify the studies comprehensively. This review will include studies using MRI or fMRI in humans to directly compare brain activation, functional connectivity, or structure in relation to DRD between addicted and healthy individuals or continuously assess addiction severity in the context of DRD. Two independent reviewers will determine studies that meet the inclusion criteria for this review, extract data from included studies, and assess the quality of included studies using the Grading of Recommendations Assessment, Development and Evaluation framework. Then, narrative review will be used to explicate the differences in structural and functional correlates of DRD implicated by the literature and assess the strength of evidence for this conclusion. This review will provide a needed critical exegesis of the MRI studies that have been conducted investigating

  8. Delay discounting, impulsiveness, and addiction severity in opioid-dependent patients.

    Science.gov (United States)

    Robles, Elias; Huang, B Emma; Simpson, Pippa M; McMillan, Donald E

    2011-12-01

    Individuals who abuse drugs show higher delay discounting (DD) rate and impulsiveness scores compared with controls; however, it is unclear if DD rate covaries with severity of the addiction or if an individual's discounting rate can be changed by effective substance abuse treatment. This study compared methadone maintenance treatment (MMT) patients (n = 30) who had not used illegal drugs for 2 years with drug-using MMT patients (n = 30) and controls (n = 25) in terms of addiction severity, DD rate, and impulsiveness. Methadone patients abstinent from illegal drugs scored significantly lower on a number of addiction severity measures than the drug-using methadone patients. In addition, both groups of MMT patients showed significantly higher rates of DD and impulsiveness than the control group; however, no differences in DD rate or impulsiveness were found between the groups of patients. Results suggest that DD rate and impulsiveness may not covary with indicators of addiction severity in MMT patients. Published by Elsevier Inc.

  9. Hypothetical intertemporal choice and real economic behavior: delay discounting predicts voucher redemptions during contingency-management procedures.

    Science.gov (United States)

    Bickel, Warren K; Jones, Bryan A; Landes, Reid D; Christensen, Darren R; Jackson, Lisa; Mancino, Michael

    2010-12-01

    Delay discounting rates are predictive of drug use status, the likelihood of becoming abstinent, and a variety of health behaviors. Rates of delay discounting may also be related to other relevant behaviors associated with addiction, such as the frequency at which individuals redeem contingency management voucher earnings. This study examined the discounting rates of 152 participants in a buprenorphine treatment program for opioid abuse. Participants received up to 12 weeks of buprenorphine treatment combined with contingency management. Participant's drug use was measured via urine specimens submitted three times a week. Successive negative urine specimens were reinforced with increasing amounts of money. After each negative urine specimen, a participant could either redeem his or her earnings or accumulate it in an account. Analysis of the frequency of redemptions showed that participants with higher rates of delay discounting at study intake redeemed their earnings significantly more often than participants with lower rates of discounting. Age and income also predicted redemption rates. We suggest that delay discounting rates can be used to predict redemption behaviors in a contingency management treatment program and that these findings are consistent with the recent theory of the competing neurobehavioral decision systems. PsycINFO Database Record (c) 2010 APA, all rights reserved.

  10. On the Expected Discounted Penalty Function for the Classical Risk Model with Potentially Delayed Claims and Random Incomes

    Directory of Open Access Journals (Sweden)

    Huiming Zhu

    2014-01-01

    Full Text Available We focus on the expected discounted penalty function of a compound Poisson risk model with random incomes and potentially delayed claims. It is assumed that each main claim will produce a byclaim with a certain probability and the occurrence of the byclaim may be delayed depending on associated main claim amount. In addition, the premium number process is assumed as a Poisson process. We derive the integral equation satisfied by the expected discounted penalty function. Given that the premium size is exponentially distributed, the explicit expression for the Laplace transform of the expected discounted penalty function is derived. Finally, for the exponential claim sizes, we present the explicit formula for the expected discounted penalty function.

  11. Delayed discounting and hedonic hunger in the prediction of lab-based eating behavior.

    Science.gov (United States)

    Ely, Alice V; Howard, Janna; Lowe, Michael R

    2015-12-01

    Research suggests that characteristics identified in obese individuals, such as impulsive decision-making and hedonic hunger, may exist in nonobese populations. This study examined the independent and interactive effects of impulsive decision-making (measured via delay discounting, DD) and hedonic hunger (assessed with the Power of Food Scale, PFS) on food intake. Female participants (N=78) ate a self-determined amount of plain oatmeal, completed self-report measures and the delay discounting task, and participated in a sham taste test of palatable sweet and salty foods. Unexpectedly, PFS and DD scores interacted to predict consumption of the total amount of food consumed, and of oatmeal alone, but not of snack food alone. High-PFS participants consumed more when also high in DD, while low-PFS participants showed the opposite pattern of consumption. The findings identify variables that may increase propensity toward overconsumption and potential weight gain; future research is necessary to evaluate the utility of these constructs to predict increases in BMI over time. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Delay and reward choice in ADHD: an experimental test of the role of delay aversion.

    Science.gov (United States)

    Marco, Rafaela; Miranda, Ana; Schlotz, Wolff; Melia, Amanda; Mulligan, Aisling; Müller, Ueli; Andreou, Penny; Butler, Louise; Christiansen, Hanna; Gabriels, Isabel; Medad, Sheera; Albrecht, Bjorn; Uebel, Henrik; Asherson, Phillip; Banaschewski, Tobias; Gill, Michael; Kuntsi, Jonna; Mulas, Fernando; Oades, Robert; Roeyers, Herbert; Steinhausen, Hans-Christoph; Rothenberger, Aribert; Faraone, Stephen V; Sonuga-Barke, Edmund J S

    2009-05-01

    Children with attention deficit/hyperactivity disorder (ADHD) choose smaller sooner (SS) over larger later (LL) rewards more than controls. Here we assess the contributions of impulsive drive for immediate rewards (IDIR) and delay aversion (DAv) to this pattern. We also explore the characteristics of, and the degree of familiality in, ADHD SS responders. We had 360 ADHD probands; 349 siblings and 112 controls (aged between 6 to 17 years) chose between SS (1 point after 2 s) and LL reward (2 points after 30 s) outcomes on the Maudsley Index of Delay Aversion (Kuntsi, Oosterlaan, & Stevenson, 2001): Under one condition SS choice led to less overall trial delay under another it did not. ADHD participants chose SS more than controls under both conditions. This effect was larger when SS choice reduced trial delay. ADHD SS responders were younger, had lower IQ, more conduct disorder and had siblings who were more likely to be SS responders themselves. The results support a dual component model in which both IDIR and DAv contribute to SS choice in ADHD. SS choice may be a marker of an ADHD motivational subtype.

  13. Individual Differences in Discount Rate Are Associated With Demand for Self-Administered Cocaine, But Not Sucrose

    OpenAIRE

    Koffarnus, Mikhail N.; Woods, James H.

    2011-01-01

    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 i.v. 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 reinforceme...

  14. Delay Discounting Mediates Parent-Adolescent Relationship Quality and Risky Sexual Behavior for Low Self-Control Adolescents

    Science.gov (United States)

    Kahn, Rachel E.; Holmes, Christopher; Farley, Julee P.; Kim-Spoon, Jungmeen

    2015-01-01

    Parent-adolescent relationship quality and delay discounting may play important roles in adolescents’ sexual decision making processes, and levels of self-control during adolescence could act as a buffer within these factors. This longitudinal study included 219 adolescent (55% male; mean age = 12.66 years at Wave 1; mean age = 15.10 years at Wave 2) and primary caregiver dyads. Structural equation modeling was utilized to determine whether delay discounting mediated the association between parent-adolescent relationship quality and adolescents’ risky sexual behavior and how this mediated association may differ between those with high versus low self-control. The results revealed parent-adolescent relationship quality plays a role in the development of risky sexual behavior indirectly through levels of delay discounting, but only for adolescents with low self-control. These findings could inform sex education policies and health prevention programs that address adolescent risky sexual behavior. PMID:26202153

  15. Elevated outcome-anticipation and outcome-evaluation ERPs associated with a greater preference for larger-but-delayed rewards.

    Science.gov (United States)

    Pornpattananangkul, Narun; Nadig, Ajay; Heidinger, Storm; Walden, Keegan; Nusslock, Robin

    2017-06-01

    Although waiting for a reward reduces or discounts its value, some people have a stronger tendency to wait for larger rewards and forgo smaller-but-immediate rewards. This ability to delay gratification is captured by individual differences in so-called intertemporal choices in which individuals are asked to choose between larger-but-delayed versus smaller-but-immediate rewards. The current study used event-related potentials (ERPs) to examine whether enhancement in two neurocognitive processes, outcome anticipation and outcome evaluation, modulate individual variability in intertemporal responses. After completing a behavioral intertemporal choice task, 34 participants performed an ERP gambling task. From this ERP task, we separately examined individual differences in outcome anticipation (stimulus-preceding negativity; SPN), early outcome valuation (feedback-related negativity; FRN), and late outcome evaluation (P3). We observed that both elevated outcome-anticipation (SPN) and late outcome-evaluation (P3) neural processes predicted a stronger preference toward larger-but-delayed rewards. No relationship was observed between intertemporal responses and early outcome evaluation (FRN), indicating that the relationship between outcome evaluation and intertemporal responses was specific to the late outcome-evaluation processing stream. Moreover, multiple regression analyses indicated that the SPN and P3 independently modulate individual differences in intertemporal responses, suggesting separate mechanisms underlie the relationship between these two neurocognitive processes and intertemporal responses. Accordingly, we identify two potential neurocognitive modulators of individual variability in intertemporal responses. We discuss the mechanisms underlying these modulators in terms of anticipation-related processing (SPN) and a saliency bias toward gain (compared to loss) outcomes (P3).

  16. Haloperidol and Rimonabant Increase Delay Discounting in Rats Fed High-Fat and Standard-Chow Diets

    Science.gov (United States)

    Boomhower, Steven R.; Rasmussen, Erin B.

    2016-01-01

    The dopamine and endocannabinoid neurotransmitter systems have been implicated in delay discounting, a measure of impulsive choice, and obesity. The current study was designed to determine the extent to which haloperidol and rimonabant affected delay discounting in rats fed standard-chow and high-fat diets. Sprague-Dawley rats were allowed to free-feed under a high-fat diet (4.73 kcal/g) or a standard-chow diet (3.0 kcal/g) for three months. Then, operant sessions began in which rats (n = 9 standard chow; n = 10 high-fat) chose between one sucrose pellet delivered immediately vs. three sucrose pellets after a series of delays. In another condition, carrot-flavored pellets replaced sucrose pellets. After behavior stabilized, acute injections of rimonabant (0.3-10 mg/kg) and haloperidol (0.003-0.1 mg/kg) were administered i.p. before some choice sessions in both pellet conditions. Haloperidol and rimonabant increased discounting in both groups of rats by decreasing percent choice for the larger reinforcer and area-under-the-curve (AUC) values. Rats in the high-fat diet condition demonstrated increased sensitivity to haloperidol compared to chow-fed controls: haloperidol increased discounting in both dietary groups in the sucrose condition,, but only in the high-fat-fed rats in the carrot-pellet condition. These findings indicate that blocking D2 and CB1 receptors results in increased delay discounting, and that a high-fat diet may alter sensitivity to dopaminergic compounds using the delay-discounting task. PMID:25000488

  17. An EPQ model under cash discount and permissible delay in payments derived without derivatives

    Directory of Open Access Journals (Sweden)

    Huang Yung-Fu

    2007-01-01

    Full Text Available The main purpose of this paper is to investigate the case where the retailer’s unit selling price and the purchasing price per unit are not necessarily equal within the economic production quantity (EPQ framework under cash discount and permissible delay in payments. We establish the retailer’s inventory system as a cost minimization problem to determine the retailer’s optimal inventory cycle time, optimal order quantity and optimal payment time. This paper provides an algebraic approach to determine the optimal cycle time, optimal order quantity and optimal payment time. This approach provides one theorem to efficiently determine the optimal solution. Some previously published results of other researchers are deduced as special cases. Finally, numerical examples are given to illustrate the result and the managerial insights are also obtained.

  18. Improving control over the impulse for reward: sensitivity of harmful alcohol drinkers to delayed reward but not immediate punishment.

    Science.gov (United States)

    Rossiter, Sarah; Thompson, Julian; Hester, Robert

    2012-09-01

    Cognitive control dysfunction has been identified in dependent alcohol users and implicated in the transition from abuse to dependence, although evidence of dyscontrol in chronic but non-dependent 'harmful' alcohol abusers is mixed. The current study examined harmful alcohol users response inhibition over rewarding stimuli in the presence of monetary reward and punishment, to determine whether changes in sensitivity to these factors, noted in imaging studies of dependent users, influences impulse control. Harmful (n=30) and non-hazardous (n=55) alcohol users were administered a Monetary Incentive Go/No-go task that required participants to inhibit a prepotent motor response associated with reward. Harmful alcohol users showed a significantly poorer ability to withhold their impulse for a rewarding stimulus in the presence of immediate monetary punishment for failure, while retaining equivalent response inhibition performance under neutral conditions (associated with neither monetary loss or gain), and significantly better performance under delayed reward conditions. The results of the present study suggest that non-dependent alcohol abusers have altered sensitivity to reward and punishment that influences their impulse control for reward, in the absence of gross dyscontrol that is consistent with past findings in which such performance contingencies were not used. The ability of delayed monetary reward, but not punishment, to increase sustained impulse control in this sample has implications for the mechanism that might underlie the transition from alcohol abuse to dependence, as well as intervention strategies aimed at preventing this transition. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Reward: commentary. Temporal discounting in conduct disorder: toward an experience-adaptation hypothesis of the role of psychosocial insecurity.

    Science.gov (United States)

    Sonuga-Barke, Edmund J S

    2014-02-01

    Young people with conduct disorder often experience histories of psychosocial adversity and socioeconomic insecurity. For these individuals, real-world future outcomes are not only delayed in their delivery but also highly uncertain. Under such circumstances, accentuated time preference (extreme favoring of the present over the future) is a rational response to the everyday reality of social and economic transactions. Building on this observation, the author sets out the hypothesis that the exaggerated temporal discounting displayed by individuals with conduct disorder reported by White et al. (2014) is an adaptation to chronic exposure to psychosocial insecurity during development. The author postulates that this adaptation leads to (a) a decision-making bias whereby delay and uncertainty are coded as inseparable characteristics of choice outcomes and/or (b) reprogramming of the brain networks regulating intertemporal decision making. Future research could explore the putative role of environmental exposures to adversity in the development of exaggerated temporal discounting in conduct disorder as well as the mediating role of putative cognitive and neurobiological adaptations.

  20. Effects of chronic administration of drugs of abuse on impulsive choice (delay discounting) in animal models.

    Science.gov (United States)

    Setlow, Barry; Mendez, Ian A; Mitchell, Marci R; Simon, Nicholas W

    2009-09-01

    Drug-addicted individuals show high levels of impulsive choice, characterized by preference for small immediate over larger but delayed rewards. Although the causal relationship between chronic drug use and elevated impulsive choice in humans has been unclear, a small but growing body of literature over the past decade has shown that chronic drug administration in animal models can cause increases in impulsive choice, suggesting that a similar causal relationship may exist in human drug users. This article reviews this literature, with a particular focus on the effects of chronic cocaine administration, which have been most thoroughly characterized. The potential mechanisms of these effects are described in terms of drug-induced neural alterations in ventral striatal and prefrontal cortical brain systems. Some implications of this research for pharmacological treatment of drug-induced increases in impulsive choice are discussed, along with suggestions for future research in this area.

  1. Money earlier or later? Simple heuristics explain intertemporal choices better than delay discounting does.

    Science.gov (United States)

    Ericson, Keith M Marzilli; White, John Myles; Laibson, David; Cohen, Jonathan D

    2015-06-01

    Heuristic models have been proposed for many domains involving choice. We conducted an out-of-sample, cross-validated comparison of heuristic models of intertemporal choice (which can account for many of the known intertemporal choice anomalies) and discounting models. Heuristic models outperformed traditional utility-discounting models, including models of exponential and hyperbolic discounting. The best-performing models predicted choices by using a weighted average of absolute differences and relative percentage differences of the attributes of the goods in a choice set. We concluded that heuristic models explain time-money trade-off choices in experiments better than do utility-discounting models. © The Author(s) 2015.

  2. Money Earlier or Later? Simple Heuristics Explain Intertemporal Choices Better than Delay Discounting1

    Science.gov (United States)

    Marzilli Ericson, Keith M.; White, John Myles; Laibson, David; Cohen, Jonathan D.

    2015-01-01

    Heuristic models have been proposed for many domains of choice. We compare heuristic models of intertemporal choice, which can account for many of the known intertemporal choice anomalies, to discounting models. We conduct an out-of-sample, cross-validated comparison of intertemporal choice models. Heuristic models outperform traditional utility discounting models, including models of exponential and hyperbolic discounting. The best performing models predict choices by using a weighted average of absolute differences and relative (percentage) differences of the attributes of the goods in a choice set. We conclude that heuristic models explain time-money tradeoff choices in experiments better than utility discounting models. PMID:25911124

  3. The nature of impulsivity: visual exposure to natural environments decreases impulsive decision-making in a delay discounting task.

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

    Full Text Available The benefits of visual exposure to natural environments for human well-being in areas of stress reduction, mood improvement, and attention restoration are well documented, but the effects of natural environments on impulsive decision-making remain unknown. Impulsive decision-making in delay discounting offers generality, predictive validity, and insight into decision-making related to unhealthy behaviors. The present experiment evaluated differences in such decision-making in humans experiencing visual exposure to one of the following conditions: natural (e.g., mountains, built (e.g., buildings, or control (e.g., triangles using a delay discounting task that required participants to choose between immediate and delayed hypothetical monetary outcomes. Participants viewed the images before and during the delay discounting task. Participants were less impulsive in the condition providing visual exposure to natural scenes compared to built and geometric scenes. Results suggest that exposure to natural environments results in decreased impulsive decision-making relative to built environments.

  4. The effect of future time perspective on delay discounting is mediated by the gray matter volume of vmPFC.

    Science.gov (United States)

    Guo, Yiqun; Chen, Zhiyi; Feng, Tingyong

    2017-07-28

    Although several previous studies have shown that individuals' attitude towards time could affect their intertemporal preference, little is known about the neural basis of the relation between time perspective (TP) and delay discounting. In the present study, we quantified the gray matter (GM) cortical volume using voxel-based morphometry (VBM) methods to investigate the effect of TP on delay discounting (DD) across two independent samples. For group 1 (102 healthy college students; 46 male; 20.40 ± 1.87 years), behavioral results showed that only Future TP was a significant predictor of DD, and higher scores on Future TP were related to lower discounting rates. Whole-brain analysis revealed that steeper discounting correlated with greater GM volume in the ventromedial prefrontal cortex (vmPFC) and ventral part of posterior cingulate cortex (vPCC). Also, GM volume of a cluster in the vmPFC was correlated with Future TP. Interestingly, there was an overlapping region in vmPFC that was correlated with both DD and Future TP. Region-of-interest analysis further indicated that the overlapping region of vmPFC played a partially mediating role in the relation between Future TP and DD in the other independent dataset (Group 2, 36 healthy college students; 14 male; 20.18±1.80 years). Taken together, our results provide a new perspective from neural basis for explaining the relation between DD and future TP. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Heaven can wait. How religion modulates temporal discounting.

    Science.gov (United States)

    Paglieri, Fabio; Borghi, Anna M; Colzato, Lorenza S; Hommel, Bernhard; Scorolli, Claudia

    2013-11-01

    Evidence suggests that religious systems have specific effects on attentional and action control processes. The present study investigated whether religions also modulate choices that involve higher-order knowledge and the delay of gratification in particular. We tested Dutch Calvinists, Italian Catholics, and Atheists from both countries/cultures using an intertemporal choice task where participants could choose between a small immediate and a larger delayed monetary reward. Based on the Calvinist theory of predestination and the Catholic concept of a cycle of sin-confession-expiation, we predicted a reduced delay tolerance, i.e., higher discount rate, for Italian Catholics than for Dutch Calvinists, and intermediate rates for the two atheist groups. Analyses of discount rates support our hypotheses. We also found a magnitude effect on temporal discounting and faster responses for large than for small rewards across religions and countries/cultures. We conclude that temporal discounting is specifically modulated by religious upbringing rather than by generic cultural differences.

  6. Episodic future thinking reduces delay discounting and cigarette demand: an investigation of the good-subject effect.

    Science.gov (United States)

    Stein, Jeffrey S; Tegge, Allison N; Turner, Jamie K; Bickel, Warren K

    2018-04-01

    Episodic future thinking (EFT), an intervention involving mental simulation of future events, has been shown to reduce both delay discounting and cigarette self-administration. In the present study, we extended these findings by showing that EFT in a web-based sample of smokers reduces delay discounting and intensity of demand for cigarettes (ad libitum consumption) in a hypothetical purchase task. No effect was observed on elasticity of demand (sensitivity to price) or cigarette craving. We also explored whether demand characteristics (specifically, the "good-subject" effect) might be responsible for observed effects. EFT participants were significantly better able than control participants to discern the experimental hypothesis. However, EFT participants were not better than controls at identifying whether they had been assigned to the experimental group and, likewise, showed no differences in attitudes about the experiment and experimenter. Importantly, effects of EFT on delay discounting and demand remained significant even when controlling for measures of demand characteristics, indicating that EFT's effects are independent of participants' perceptions about the experiment.

  7. Delay Discounting Mediates Parent-Adolescent Relationship Quality and Risky Sexual Behavior for Low Self-Control Adolescents.

    Science.gov (United States)

    Kahn, Rachel E; Holmes, Christopher; Farley, Julee P; Kim-Spoon, Jungmeen

    2015-09-01

    Parent-adolescent relationship quality and delay discounting may play important roles in adolescents' sexual decision making processes, and levels of self-control during adolescence could act as a buffer within these factors. This longitudinal study included 219 adolescent (55 % male; mean age = 12.66 years at Wave 1; mean age = 15.10 years at Wave 2) and primary caregiver dyads. Structural equation modeling (SEM) was utilized to determine whether delay discounting mediated the association between parent-adolescent relationship quality and adolescents' risky sexual behavior and how this mediated association may differ between those with high versus low self-control. The results revealed parent-adolescent relationship quality plays a role in the development of risky sexual behavior indirectly through levels of delay discounting, but only for adolescents with low self-control. These findings could inform sex education policies and health prevention programs that address adolescent risky sexual behavior.

  8. Temporal discounting across three psychiatric disorders: Anorexia nervosa, obsessive compulsive disorder, and social anxiety disorder

    Science.gov (United States)

    Steinglass, Joanna E.; Lempert, Karolina M.; Choo, Tse-Hwei; Kimeldorf, Marcia B.; Wall, Melanie; Walsh, B. Timothy; Fyer, Abby J.; Schneier, Franklin R.; Simpson, H. Blair

    2018-01-01

    Background Temporal discounting refers to the tendency for rewards to lose value as the expected delay to receipt increases. Individuals with anorexia nervosa (AN) have been found to show reduced temporal discounting rates, indicating a greater preference for delayed rewards compared to healthy peers. Obsessive–compulsive disorder (OCD) and social anxiety disorder (SAD) commonly co-occur with AN, and anxiety has been related to development and prognosis of AN. We examined whether reduced temporal discounting is present across these potentially related disorders, and explored the relationship between temporal discounting and anxiety trans-diagnostically. Methods One hundred ninety six individuals (75 healthy controls (HC); 50 OCD; 27 AN; 44 SAD) completed two temporal discounting tasks in which they chose between smaller-sooner and larger-later monetary rewards. Two measures of discounting—discount rate and discount factor—were compared between diagnostic groups, and associations with anxious traits were examined. Results Individuals with AN showed decreased temporal discounting compared to HC. OCD and SAD groups did not differ significantly from HC. Across the sample, anxiety was associated with decreased discounting; more anxious individuals showed a greater preference for delayed reward. Conclusions We replicated the findings that individuals with AN show an increased preference for delayed reward relative to HC and that individuals with OCD do not differ from HC. We also showed that individuals with SAD do not differ from HC in discounting. Across this large sample, two measures of anxious temperament were associated with temporal discounting. These data raise new questions about the relationship between this dimensional trait and psychopathology. PMID:28009473

  9. Impulsive Choice, Alcohol Consumption, and Pre-Exposure to Delayed Rewards: II. Potential Mechanisms

    Science.gov (United States)

    Stein, Jeffrey S.; Renda, C. Renee; Hinnenkamp, Jay E.; Madden, Gregory J.

    2014-01-01

    In a prior study (Stein et al., 2013), we reported that rats pre-exposed to delayed rewards made fewer impulsive choices, but consumed more alcohol (12% wt/vol), than rats pre-exposed to immediate rewards. To understand the mechanisms that produced these findings, we again pre-exposed rats to either delayed (17.5 s; n = 32) or immediate (n = 30) rewards. In post-tests, delay-exposed rats made significantly fewer impulsive choices at both 15- and 30-s delays to a larger, later food reward than the immediacy-exposed comparison group. Behavior in an open-field test provided little evidence of differential stress exposure between groups. Further, consumption of either 12% alcohol or isocaloric sucrose in subsequent tests did not differ between groups. Because Stein et al. introduced alcohol concentration gradually (3–12%), we speculate that their group differences in 12% alcohol consumption were not determined by alcohol’s pharmacological effects, but by another variable (e.g., taste) that was preserved as an artifact from lower concentrations. We conclude that pre-exposure to delayed rewards generalizes beyond the pre-exposure delay; however, this same experimental variable does not robustly influence alcohol consumption. PMID:25418607

  10. Increased Capacity to Delay Reward in Anorexia Nervosa

    NARCIS (Netherlands)

    Steinglass, J.E.; Figner, B.; Berkowitz, S.; Simpson, H.B.; Weber, E.U.; Walsh, B.T.

    2012-01-01

    Individuals with anorexia nervosa (AN) are often characterized as possessing excessive self-control and are unusual in their ability to reduce or avoid the consumption of palatable foods. This behavior promotes potentially life-threatening weight loss and suggests disturbances in reward processing.

  11. Associations between Antisocial Personality Disorder and Sex on Discounting Rates.

    Science.gov (United States)

    Andrade, Leonardo F; Riven, Levi; Petry, Nancy M

    2014-12-01

    Numerous studies show that individuals with substance use and gambling problems discount delayed and probabilistic outcomes at different rates than controls. Few studies, however, investigated the association of discounting with antisocial personality disorders (ASPD), and none evaluated whether sex impacts these relationships. Because females with ASPD exhibit different patterns of antisocial behavior than their male counterparts, they may also differ in their decision-making tendencies. This study examined the effects of ASPD and sex on discounting in pathological gamblers. Results revealed effects of ASPD, and an interaction between ASPD and sex, on probability discounting rates. None of these variables, however, were related to delay discounting. Females with ASPD highly preferred probabilistic outcomes, suggesting that female gamblers with ASPD are particularly impulsive when it comes to probabilistic rewards. Greater understanding of sex differences in ASPD might help guide the selection of more effective sex-specific prevention and treatment programs.

  12. Transactional Problem Content in Cost Discounting: Parallel Effects for Probability and Delay

    Science.gov (United States)

    Jones, Stephen; Oaksford, Mike

    2011-01-01

    Four experiments investigated the effects of transactional content on temporal and probabilistic discounting of costs. Kusev, van Schaik, Ayton, Dent, and Chater (2009) have shown that content other than gambles can alter decision-making behavior even when associated value and probabilities are held constant. Transactions were hypothesized to lead…

  13. Associations between depression, distress tolerance, delay discounting, and alcohol-related problems in European American and African American college students.

    Science.gov (United States)

    Dennhardt, Ashley A; Murphy, James G

    2011-12-01

    Although levels of heavy drinking and alcohol-related problems are high in college students, there is significant variability in the number and type of problems experienced, even among students who drink heavily. African American students drink less and experience fewer alcohol-related problems than European American students, but are still at risk, and little research has investigated the potentially unique patterns and predictors of problems among these students. Depression, distress tolerance, and delay discounting have been implicated in adult substance abuse and may be important predictors of alcohol problem severity among college students. We examined the relationship between these variables and alcohol-related problems among African American and European American students (N = 206; 53% female; 68% European American; 28% African American) who reported recent heavy drinking. In regression models that controlled for drinking level, depression, distress tolerance, and delay discounting were associated with alcohol problems among African American students, but only depression was associated with alcohol problems among European American students. These results suggest that negative affect is a key risk factor for alcohol problems among college student drinkers. For African American students, the inability to tolerate negative emotions and to organize their behavior around future outcomes may also be especially relevant risk factors.

  14. Rare Neural Correlations Implement Robotic Conditioning with Delayed Rewards and Disturbances

    Science.gov (United States)

    Soltoggio, Andrea; Lemme, Andre; Reinhart, Felix; Steil, Jochen J.

    2013-01-01

    Neural conditioning associates cues and actions with following rewards. The environments in which robots operate, however, are pervaded by a variety of disturbing stimuli and uncertain timing. In particular, variable reward delays make it difficult to reconstruct which previous actions are responsible for following rewards. Such an uncertainty is handled by biological neural networks, but represents a challenge for computational models, suggesting the lack of a satisfactory theory for robotic neural conditioning. The present study demonstrates the use of rare neural correlations in making correct associations between rewards and previous cues or actions. Rare correlations are functional in selecting sparse synapses to be eligible for later weight updates if a reward occurs. The repetition of this process singles out the associating and reward-triggering pathways, and thereby copes with distal rewards. The neural network displays macro-level classical and operant conditioning, which is demonstrated in an interactive real-life human-robot interaction. The proposed mechanism models realistic conditioning in humans and animals and implements similar behaviors in neuro-robotic platforms. PMID:23565092

  15. Hyperactivity and frustration: the influence of control over and size of rewards in delaying gratification.

    Science.gov (United States)

    Rapport, M D; Tucker, S B; DuPaul, G J; Merlo, M; Stoner, G

    1986-06-01

    This study examined the differential effects of frustration on normal children and those diagnosed as having Attention Deficit Disorder with Hyperactivity. Each group consisted of 16 boys between the ages of 6 and 8 years who were prematched for age, grade, and classroom placement. All children completed a series of arithmetic problems in order to earn toy rewards. Using a variant of Mischel's (1974) delay-of-gratification paradigm, children were presented with two choice-of-delay conditions in a randomly assigned, counterbalanced sequence: a free-choice conflict situation involving a long-passive or short-active reward delay, and a short-active delay. Results showed that a significantly greater proportion of hyperactive children chose to complete problems for an immediate reward compared to their normal control counterparts (p less than .01). Group differences were no longer apparent in the short-active delay trial. The results are discussed in terms of frustration tolerance and contributing factors such as cognitive-attentional style. Implications for treatment and future directions are delineated.

  16. Der Einfluss von COMT Val158Met auf neuronale Korrelate von Delay Discounting bei adulten Patienten mit Aufmerksamkeitsdefizit/Hyperaktivitätsstörung (ADHS)

    OpenAIRE

    Gieseke, Heiner Alexander

    2013-01-01

    In dieser Studie führten 37 adulte Patienten mit einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) ein Delay Discounting (DD) - Paradigma aus, während gleichzeitig mittels Funktioneller-Nahinfrarotspektroskopie (fNIRS) die Gehirnaktivität der „Regions of Interest“ (ROIs) des Orbitofrontalen-Kortex (OFC) und des Dorsolateralen-Präfrontalen-Kortex (dlPFC) gemessen wurde. Mittels Fragebögen und eines Delay Discounting Tasks (DDT) wurden zusätzlich Verhaltensparameter erhoben und flosse...

  17. Does temporal discounting explain unhealthy behavior? A systematic review and reinforcement learning perspective

    Science.gov (United States)

    Story, Giles W.; Vlaev, Ivo; Seymour, Ben; Darzi, Ara; Dolan, Raymond J.

    2014-01-01

    The tendency to make unhealthy choices is hypothesized to be related to an individual's temporal discount rate, the theoretical rate at which they devalue delayed rewards. Furthermore, a particular form of temporal discounting, hyperbolic discounting, has been proposed to explain why unhealthy behavior can occur despite healthy intentions. We examine these two hypotheses in turn. We first systematically review studies which investigate whether discount rates can predict unhealthy behavior. These studies reveal that high discount rates for money (and in some instances food or drug rewards) are associated with several unhealthy behaviors and markers of health status, establishing discounting as a promising predictive measure. We secondly examine whether intention-incongruent unhealthy actions are consistent with hyperbolic discounting. We conclude that intention-incongruent actions are often triggered by environmental cues or changes in motivational state, whose effects are not parameterized by hyperbolic discounting. We propose a framework for understanding these state-based effects in terms of the interplay of two distinct reinforcement learning mechanisms: a “model-based” (or goal-directed) system and a “model-free” (or habitual) system. Under this framework, while discounting of delayed health may contribute to the initiation of unhealthy behavior, with repetition, many unhealthy behaviors become habitual; if health goals then change, habitual behavior can still arise in response to environmental cues. We propose that the burgeoning development of computational models of these processes will permit further identification of health decision-making phenotypes. PMID:24659960

  18. Neural and personality correlates of individual differences related to the effects of acute tryptophan depletion on future reward evaluation.

    Science.gov (United States)

    Demoto, Yoshihiko; Okada, Go; Okamoto, Yasumasa; Kunisato, Yoshihiko; Aoyama, Shiori; Onoda, Keiichi; Munakata, Ayumi; Nomura, Michio; Tanaka, Saori C; Schweighofer, Nicolas; Doya, Kenji; Yamawaki, Shigeto

    2012-01-01

    In general, humans tend to discount the value of delayed reward. An increase in the rate of discounting leads to an inability to select a delayed reward over a smaller immediate reward (reward-delay impulsivity). Although deficits in the serotonergic system are implicated in this reward-delay impulsivity, there is individual variation in response to serotonin depletion. The aim of the present study was to investigate whether the effects of serotonin depletion on the ability to evaluate future reward are affected by individual personality traits or brain activation. Personality traits were assessed using the NEO-Five Factor Inventory and Temperament and Character Inventory. The central serotonergic levels of 16 healthy volunteers were manipulated by dietary tryptophan depletion. Subjects performed a delayed reward choice task that required the continuous estimation of reward value during functional magnetic resonance imaging scanning. Discounting rates were increased in 9 participants, but were unchanged or decreased in 7 participants in response to tryptophan depletion. Participants whose discounting rate was increased by tryptophan depletion had significantly higher neuroticism and lower self-directedness. Furthermore, tryptophan depletion differentially affected the groups in terms of hemodynamic responses to the value of predicted future reward in the right insula. These results suggest that individuals who have high neuroticism and low self-directedness as personality traits are particularly vulnerable to the effect of low serotonin on future reward evaluation accompanied by altered brain activation patterns. Copyright © 2012 S. Karger AG, Basel.

  19. Rewards.

    Science.gov (United States)

    Gunderman, Richard B; Kamer, Aaron P

    2011-05-01

    For much of the 20th century, psychologists and economists operated on the assumption that work is devoid of intrinsic rewards, and the only way to get people to work harder is through the use of rewards and punishments. This so-called carrot-and-stick model of workplace motivation, when applied to medical practice, emphasizes the use of financial incentives and disincentives to manipulate behavior. More recently, however, it has become apparent that, particularly when applied to certain kinds of work, such approaches can be ineffective or even frankly counterproductive. Instead of focusing on extrinsic rewards such as compensation, organizations and their leaders need to devote more attention to the intrinsic rewards of work itself. This article reviews this new understanding of rewards and traces out its practical implications for radiology today. Copyright © 2011. Published by Elsevier Inc.

  20. A Reduction in Delay Discounting by Using Episodic Future Imagination and the Association with Episodic Memory Capacity.

    Science.gov (United States)

    Hu, Xiaochen; Kleinschmidt, Helena; Martin, Jason A; Han, Ying; Thelen, Manuela; Meiberth, Dix; Jessen, Frank; Weber, Bernd

    2016-01-01

    Delay discounting (DD) refers to the phenomenon that individuals discount future consequences. Previous studies showed that future imagination reduces DD, which was mediated by functional connectivity between medial prefrontal valuation areas and a key region for episodic memory (hippocampus). Future imagination involves an initial period of construction and a later period of elaboration, with the more elaborative latter period recruiting more cortical regions. This study examined whether elaborative future imagination modulated DD, and if so, what are the underlying neural substrates. It was assumed that cortical areas contribute to the modulation effect during the later period of imagination. Since future imagination is supported by episodic memory capacity, we additionally hypothesize that the neural network underlying the modulation effect is related to individual episodic memory capacity. Twenty-two subjects received an extensive interview on personal future events, followed by an fMRI DD experiment with and without the need to perform elaborative future imagination simultaneously. Subjects' episodic memory capacity was also assessed. Behavioral results replicate previous findings of a reduced discount rate in the DD plus imagination condition compared to the DD only condition. The behavioral effect positively correlated with: (i) subjective value signal changes in midline brain structures during the initial imagination period; and (ii) signal changes in left prefrontoparietal areas during the later imagination period. Generalized psychophysiological interaction (gPPI) analyses reveal positive correlations between the behavioral effect and functional connectivity among the following areas: right anterior cingulate cortex (ACC) and left hippocampus; left inferior parietal cortex (IPC) and left hippocampus; and left IPC and bilateral occipital cortices. These changes in functional connectivity are also associated with episodic memory capacity. A hierarchical

  1. The role of empathy in choosing rewards from another’s perspective

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    Garret eO'Connell

    2013-05-01

    Full Text Available As social animals, we regularly act in the interest of others by making decisions on their behalf. These decisions can take the form of choices between smaller short-term rewards and larger long-term rewards, and can be effectively indexed by temporal discounting. In a temporal discounting paradigm, a reward loses subjective value with increasing delay presumably because it becomes more difficult to simulate how much the recipient (e.g. future self will value it. If this is the case, then the value of delayed rewards should be discounted even more steeply when we are choosing for someone whose feelings we do not readily simulate, such as socially distant strangers. Second, the ability to simulate shows individual differences and is indexed by trait empathy. We hypothesised that individuals high in trait empathy will more readily simulate, and hence discount less steeply for distant others, compared to those who are low on trait empathy. To test these predictions, we asked 63 participants from the general population to perform a temporal discounting task from the perspectives of close and distant others, as well as their own. People were found to discount less steeply for themselves, and the steepness of temporal discounting increased with increasing distance from self. Additionally, individuals who scored high in trait empathy were found to discount less steeply for distant others compared to those who scored low. These findings confirm the role of empathy in determining how we choose rewards for others.

  2. Anodal Stimulation of the Left DLPFC Increases IGT Scores and Decreases Delay Discounting Rate in Healthy Males

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    Qinghua He

    2016-09-01

    Full Text Available Previous correlational imaging studies have implicated the dorsolateral prefrontal cortex (DLPFC in decision making. Using High-Definition Transcranial Direct Current Stimulation (HD-tDCS, the present study directly investigated the causal role of the DLPFC in performing the Iowa Gambling Task (IGT and the Inter-Temporal Choice (ITC task. Three experiments were conducted: Exp. 1 (N = 41 to study the left DLPFC, Exp. 2 (N = 49 to study the right DLPFC, and Exp. 3 (N = 20, a subset of those in Exp. 1 to switch the experimental and control conditions. All participants were healthy male college students. For Exps. 1 and 2, participants were randomly assigned to either the HD- tDCS or the sham stimulation condition. For Exp. 3, participants were assigned to the condition they were not in during Exp. 1. Results showed that HD-tDCS over the left DLPFC increased IGT score, decreased the recency parameter in IGT, and lowered delay discounting rate (k in the ITC task. We discussed the potential roles of impulse control and time perception in mediating the effect of tDCS stimulation of left DLPFC on decision making. Our results have clinical implications for the treatment of disorders involving poor decision-making, such as addictions.

  3. Stress hormones predict hyperbolic time-discount rates six months later in adults.

    Science.gov (United States)

    Takahashi, Taiki; Shinada, Mizuho; Inukai, Keigo; Tanida, Shigehito; Takahashi, Chisato; Mifune, Nobuhiro; Takagishi, Haruto; Horita, Yutaka; Hashimoto, Hirofumi; Yokota, Kunihiro; Kameda, Tatsuya; Yamagishi, Toshio

    2010-01-01

    Stress hormones have been associated with temporal discounting. Although time-discount rate is shown to be stable over a long term, no study to date examines whether individual differences in stress hormones could predict individuals' time-discount rates in the relatively distant future (e.g., six month later), which is of interest in neuroeconomics of stress-addiction association. We assessed 87 participants' salivary stress hormone (cortisol, cortisone, and alpha-amylase) levels and hyperbolic discounting of delayed rewards consisting of three magnitudes, at the time-interval of six months. For salivary steroid assays, we employed a liquid chromatography/ mass spectroscopy (LC/MS) method. The correlations between the stress hormone levels and time-discount rates were examined. We observed that salivary alpha-amylase (sAA) levels were negatively associated with time-discount rates in never-smokers. Notably, salivary levels of stress steroids (i.e., cortisol and cortisone) negatively and positively related to time-discount rates in men and women, respectively, in never-smokers. Ever-smokers' discount rates were not predicted from these stress hormone levels. Individual differences in stress hormone levels predict impulsivity in temporal discounting in the future. There are sex differences in the effect of stress steroids on temporal discounting; while there was no sex defference in the relationship between sAA and temporal discounting.

  4. Delay Discounting Rates Are Temporally Stable in an Equivalent Present Value Procedure Using Theoretical and Area under the Curve Analyses

    Science.gov (United States)

    Harrison, Justin; McKay, Ryan

    2012-01-01

    Temporal discounting rates have become a popular dependent variable in social science research. While choice procedures are commonly employed to measure discounting rates, equivalent present value (EPV) procedures may be more sensitive to experimental manipulation. However, their use has been impeded by the absence of test-retest reliability data.…

  5. Personality influences temporal discounting preferences: behavioral and brain evidence.

    Science.gov (United States)

    Manning, Joshua; Hedden, Trey; Wickens, Nina; Whitfield-Gabrieli, Susan; Prelec, Drazen; Gabrieli, John D E

    2014-09-01

    Personality traits are stable predictors of many life outcomes that are associated with important decisions that involve tradeoffs over time. Therefore, a fundamental question is how tradeoffs over time vary from person to person in relation to stable personality traits. We investigated the influence of personality, as measured by the Five-Factor Model, on time preferences and on neural activity engaged by intertemporal choice. During functional magnetic resonance imaging (fMRI), participants made choices between smaller-sooner and larger-later monetary rewards. For each participant, we estimated a constant-sensitivity discount function that dissociates impatience (devaluation of future consequences) from time sensitivity (consistency with rational, exponential discounting). Overall, higher neuroticism was associated with a relatively greater preference for immediate rewards and higher conscientiousness with a relatively greater preference for delayed rewards. Specifically, higher conscientiousness correlated positively with lower short-term impatience and more exponential time preferences, whereas higher neuroticism (lower emotional stability) correlated positively with higher short-term impatience and less exponential time preferences. Cognitive-control and reward brain regions were more activated when higher conscientiousness participants selected a smaller-sooner reward and, conversely, when higher neuroticism participants selected a larger-later reward. The greater activations that occurred when choosing rewards that contradicted personality predispositions may reflect the greater recruitment of mental resources needed to override those predispositions. These findings reveal that stable personality traits fundamentally influence how rewards are chosen over time. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Rats bred for high alcohol drinking are more sensitive to delayed and probabilistic outcomes.

    Science.gov (United States)

    Wilhelm, C J; Mitchell, S H

    2008-10-01

    Alcoholics and heavy drinkers score higher on measures of impulsivity than nonalcoholics and light drinkers. This may be because of factors that predate drug exposure (e.g. genetics). This study examined the role of genetics by comparing impulsivity measures in ethanol-naive rats selectively bred based on their high [high alcohol drinking (HAD)] or low [low alcohol drinking (LAD)] consumption of ethanol. Replicates 1 and 2 of the HAD and LAD rats, developed by the University of Indiana Alcohol Research Center, completed two different discounting tasks. Delay discounting examines sensitivity to rewards that are delayed in time and is commonly used to assess 'choice' impulsivity. Probability discounting examines sensitivity to the uncertain delivery of rewards and has been used to assess risk taking and risk assessment. High alcohol drinking rats discounted delayed and probabilistic rewards more steeply than LAD rats. Discount rates associated with probabilistic and delayed rewards were weakly correlated, while bias was strongly correlated with discount rate in both delay and probability discounting. The results suggest that selective breeding for high alcohol consumption selects for animals that are more sensitive to delayed and probabilistic outcomes. Sensitivity to delayed or probabilistic outcomes may be predictive of future drinking in genetically predisposed individuals.

  7. Temporal discounting rates and their relation to exercise behavior in older adults.

    Science.gov (United States)

    Tate, Linda M; Tsai, Pao-Feng; Landes, Reid D; Rettiganti, Mallikarjuna; Lefler, Leanne L

    2015-12-01

    As our nation's population ages, the rates of chronic illness and disability are expected to increase significantly. Despite the knowledge that exercise may prevent chronic disease and promote health among older adults, many still are inactive. Factors related to exercise behaviors have been explored in recent years. However, temporal discounting is a motivational concept that has not been explored in regard to exercise in older adults. Temporal discounting is a decision making process by which an individual chooses a smaller more immediate reward over a larger delayed reward. The aim of this study was to determine if temporal discounting rates vary between exercising and non-exercising older adults. This study used cross-sectional survey of 137 older adults living in the community. Older adults were recruited from 11 rural Arkansas churches. The Kirby delay-discounting Monetary Choice Questionnaire was used to collect discounting rates and then bivariate analysis was performed to compare temporal discounting rate between the exercisers and non-exercisers. Finally, multivariate analysis was used to compare discounting rate controlling for other covariates. The results indicated that exercising older adults display lower temporal discounting rates than non-exercising older adults. After controlling for education, exercisers still have lower temporal discounting rates than non-exercisers (phealth conditions relate to lack of exercise especially in older adults. This research suggests that if we can find appropriate incentives for discounting individuals, some type of immediate reward, then potentially we can design programs to engage and retain older adults in exercise. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Ethanol induces impulsive-like responding in a delay-of-reward operant choice procedure: impulsivity predicts autoshaping.

    Science.gov (United States)

    Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

    1998-10-01

    Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion of retractable lever conditioned stimulus (CS) followed by the response-independent delivery of food (US)] were followed by testing for impulsive-like responding in a two-choice lever-press operant delay-of-reward procedure (immediate small food reward versus delayed large food reward). Delay-of-reward functions revealed two distinct subject populations. Subjects in the Sensitive group (n=7) were more impulsive-like, increasing immediate reward choices at longer delays for large reward, while those in the Insensitive group (n=8) responded predominantly on only one lever. During the prior autoshaping phase, the Sensitive group had performed more autoshaping CRs, and correlations revealed that impulsive subjects acquired the autoshaping CR in fewer trials. In the Sensitive group, acute injections of ethanol (0, 0.25, 0.50, 1.00, 1.50 g/kg) given immediately before delay-of-reward sessions yielded an inverted U-shaped dose-response curve with increased impulsivity induced by the 0.25, 0.50, and 1.00 g/kg doses of ethanol, while choice strategy of the Insensitive group was not influenced by ethanol dose. Ethanol induced impulsive-like responding only in rats that were flexible in their response strategy (Sensitive group), and this group also performed more autoshaping CRs. Data support the hypothesis that autoshaping and impulsivity are linked.

  9. Future Discounting in Congo Basin Hunter-Gatherers Declines with Socio-Economic Transitions.

    Directory of Open Access Journals (Sweden)

    Gul Deniz Salali

    Full Text Available Humans have a tendency to discount the future; that is we value small, short-term rewards over larger, long-term rewards. The degree of future discounting, however, changes in response to socio-ecological factors. Here, we study Mbendjele BaYaka hunter-gatherers of northern Congo and their farmer neighbours to investigate adaptations in inter-temporal preferences in humans. We argue that in immediate-return systems, where food storage is absent and egalitarianism is enforced through levelling mechanisms, future discounting is an adaptive strategy to prevent wealth accumulation and the emergence of hierarchies. This ensures food sharing and allows for survival in unpredictable environments where there is risk of an energy shortfall. On the other hand, when food storage is made possible by the emergence of agriculture or as seen in some delayed-return hunter-gatherer populations, wealth accumulation, hierarchies and lower discount rates become the adaptive strategy. Therefore, individuals in immediate-return, egalitarian societies will discount the future more than those in non-egalitarian, delayed-return societies. Consistent with the predictions we found that market integration and socio-economic transitions decrease the future discounting in Mbendjele hunter-gatherers. Our measures of socio-economic differences marked this transition in hunter-gatherers living in a logging town. The degree of future-discounting was the same between more market-integrated hunter-gatherers and their farmer neighbours.

  10. Neural correlates of sample-coding and reward-coding in the delay activity of neurons in the entopallium and nidopallium caudolaterale of pigeons (Columba livia).

    Science.gov (United States)

    Johnston, Melissa; Anderson, Catrona; Colombo, Michael

    2017-01-15

    We recorded neuronal activity from the nidopallium caudolaterale, the avian equivalent of mammalian prefrontal cortex, and the entopallium, the avian equivalent of the mammalian visual cortex, in four birds trained on a differential outcomes delayed matching-to-sample procedure in which one sample stimulus was followed by reward and the other was not. Despite similar incidence of reward-specific and reward-unspecific delay cell types across the two areas, overall entopallium delay activity occurred following both rewarded and non-rewarded stimuli, whereas nidopallium caudolaterale delay activity tended to occur following the rewarded stimulus but not the non-rewarded stimulus. These findings are consistent with the view that delay activity in entopallium represents a code of the sample stimulus whereas delay activity in nidopallium caudolaterale represents a code of the possibility of an upcoming reward. However, based on the types of delay cells encountered, cells in NCL also code the sample stimulus and cells in ENTO are influenced by reward. We conclude that both areas support the retention of information, but that the activity in each area is differentially modulated by factors such as reward and attentional mechanisms. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Brain Activity in Valuation Regions while Thinking about the Future Predicts Individual Discount Rates

    Science.gov (United States)

    Cooper, Nicole; Kim, B. Kyu; Zauberman, Gal

    2013-01-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future—specifically, to judge the subjective length of future time intervals—predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future. PMID:23926268

  12. Isolating the delay component of impulsive choice in adolescent rats

    Directory of Open Access Journals (Sweden)

    Jesse eMcClure

    2014-01-01

    Full Text Available Impulsive choice — the preference for small immediate rewards over larger delayed rewards — has been linked to various psychological conditions ranging from behavioral disorders to addiction. These links highlight the critical need to dissect the various components of this multifaceted behavioral trait. Delay discounting tasks allow researchers to study an important factor of this behavior: how the subjective value of a rewards changes over a delay period. However, existing methods of delay discounting include a confound of modifying reward sizes during the procedure. Here we present a new approach of using a single constant reward size to assess delay discounting. A complementary approach could hold delay constant and assess the utility of changing quantities of a reward. Isolating these behavioral components can advance our ability to explore the behavioral complexity of impulsive choice. We present the methods for isolating delay in detail, and further capitalize on this method by pairing it with a standard peak interval task to test whether individual variation in delay discounting can be explained by differences in perception of time in male and female adolescent rats. We find that rats that were more precise in discriminating time intervals were also less impulsive in their choice. Our data suggest that differences in timing and delay discounting are not causally related, but instead are more likely influenced by a common factor. Further, the mean-level change in our measure between postnatal day 28 and 42 suggests this test may be capturing a developmental change in this factor. In summary, this new method of isolating individual components of impulsive choice (delay or quantity can be efficiently applied in either adolescent or adult animal models and may help elucidate the mechanisms underlying impulsivity and its links to psychological disorders.

  13. Time-discounting and tobacco smoking: a systematic review and network analysis.

    Science.gov (United States)

    Barlow, Pepita; McKee, Martin; Reeves, Aaron; Galea, Gauden; Stuckler, David

    2017-06-01

    Tobacco smoking harms health, so why do people smoke and fail to quit? An explanation originating in behavioural economics suggests a role for time-discounting, which describes how the value of a reward, such as better health, decreases with delay to its receipt. A large number of studies test the relationship of time-discounting with tobacco outcomes but the temporal pattern of this relationship and its variation according to measurement methods remain unclear. We review the association between time-discounting and smoking across (i) the life course, from initiation to cessation, and (ii) diverse discount measures. We identified 69 relevant studies in Web of Science and PubMed. We synthesized findings across methodologies and evaluated discount measures, study quality and cross-disciplinary fertilization. In 44 out of 54 studies, smokers more greatly discounted the future than non-smokers and, in longitudinal studies, higher discounting predicted future smoking. Smokers with lower time-discount rates achieved higher quit rates. Findings were consistent across studies measuring discount rates using hypothetical monetary or cigarette reward scenarios. The methodological quality of the majority of studies was rated as 'moderate' and co-citation analysis revealed an isolation of economics journals and a dearth of studies in public health. There is moderate yet consistent evidence that high time-discounting is a risk factor for smoking and unsuccessful cessation. Policy scenarios assuming a flat rate of population discounting may inadequately capture smokers' perceptions of costs and benefits. © The Author 2016; Published by Oxford University Press on behalf of the International Epidemiological Association

  14. Association of cognition with temporal discounting in community based older persons

    Directory of Open Access Journals (Sweden)

    Boyle Patricia A

    2012-08-01

    Full Text Available Abstract Background The objective of this study was to test the hypothesis that cognitive function is negatively associated with temporal discounting in old age. Methods Participants were 388 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging in the Chicago metropolitan area. Temporal discounting was measured using standard questions in which participants were asked to choose between an immediate, smaller payment and a delayed, larger one. Cognition was measured using a detailed battery including 19 tests. The association between cognition and temporal discounting was examined via mixed models adjusted for age, sex, education, income, and the number of chronic medical conditions. Results Descriptive data revealed a consistent pattern whereby older persons with lower cognitive function were more likely to discount greater but delayed rewards compared to those with higher cognitive function. Further, in a mixed effect model adjusted for age, sex, education, income, and chronic medical conditions, global cognitive function was negatively associated with temporal discounting (estimate = −0.45, SE = 0.18, p = 0.015, such that a person with lower cognition exhibited greater discounting. Finally, in subsequent models examining domain specific associations, perceptual speed and visuospatial abilities were associated with temporal discounting, but episodic memory, semantic memory and working memory were not. Conclusion Among older persons without dementia, a lower level of cognitive function is associated with greater temporal discounting. These findings have implications regarding the ability of older persons to make decisions that involve delayed rewards but maximize well-being.

  15. Starlings uphold principles of economic rationality for delay and probability of reward.

    Science.gov (United States)

    Monteiro, Tiago; Vasconcelos, Marco; Kacelnik, Alex

    2013-04-07

    Rationality principles are the bedrock of normative theories of decision-making in biology and microeconomics, but whereas in microeconomics, consistent choice underlies the notion of utility; in biology, the assumption of consistent selective pressures justifies modelling decision mechanisms as if they were designed to maximize fitness. In either case, violations of consistency contradict expectations and attract theoretical interest. Reported violations of rationality in non-humans include intransitivity (i.e. circular preferences) and lack of independence of irrelevant alternatives (changes in relative preference between options when embedded in different choice sets), but the extent to which these observations truly represent breaches of rationality is debatable. We tested both principles with starlings (Sturnus vulgaris), training subjects either with five options differing in food delay (exp. 1) or with six options differing in reward probability (exp. 2), before letting them choose repeatedly one option out of several binary and trinary sets of options. The starlings conformed to economic rationality on both tests, showing strong stochastic transitivity and no violation of the independence principle. These results endorse the rational choice and optimality approaches used in behavioural ecology, and highlight the need for functional and mechanistic enquiring when apparent violations of such principles are observed.

  16. Introducing Upfront Money Can Decrease Discounting in Intertemporal Choices with Losses.

    Science.gov (United States)

    Jiang, Cheng-Ming; Sun, Hong-Yue; Zheng, Sheng-Hua; Wang, Liang-Jun; Qin, Yu

    2016-01-01

    People generally tend to advance gains and postpone losses in intertemporal choice. Jiang et al. (2014) recently showed that adding upfront losses or gains to both smaller and sooner (SS) and larger and later (LL) rewards can decrease people's discounting. To account for this decrease, they proposed the salience hypothesis, which states that introducing upfront losses or gains makes the money dimension more salient than not, thus increasing people's preference for LL rewards. Considering that decreasing the discounting of delayed losses is imperative and that most previous studies have focused on intertemporal choices with gains, in the current paper we conducted two experiments and used hypothetical money outcomes to examine whether the effect of upfront money could be extended to intertemporal choices with losses. The results showed that when both SS and LL intertemporal losses were combined with an upfront loss or gain, people's discounting rate decreased and the preference for the SS option increased. This finding further supports the salience account.

  17. Dopamine in the nucleus accumbens core, but not shell, increases during signaled food reward and decreases during delayed extinction.

    Science.gov (United States)

    Biesdorf, C; Wang, A-L; Topic, B; Petri, D; Milani, H; Huston, J P; de Souza Silva, M A

    2015-09-01

    Microdialysis studies in rat have generally shown that appetitive stimuli release dopamine (DA) in the nucleus accumbens (NAc) shell and core. Here we examined the release of DA in the NAc during delivery of reward (food) and during extinction of food reward in the freely moving animal by use of in vivo microdialysis and HPLC. Fifty-two male Wistar rats were trained to receive food reward associated with appearance of cue-lights in a Skinner-box during in vivo microdialysis. Different behavioral protocols were used to assess the effects of extinction on DA and its metabolites. Results Exp. 1: (a) During a 20-min period of cued reward delivery, DA increased significantly in the NAc core, but not shell subregion; (b) for the next 60min period half of the rats underwent immediate extinction (with the CS light presented during non-reward) and the other half did not undergo extinction to the cue lights (CS was not presented during non-reward). DA remained significantly increased in both groups, providing no evidence for a decrease in DA during extinction in either NAc core or shell regions. (c) In half of the animals of the group that was not subjected to extinction, the cue lights were turned on for 30min, thus, initiating extinction to cue CS at a 1h delay from the period of reward. In this group DA in the NAc core, but not shell, significantly decreased. Behavioral analysis showed that while grooming is an indicator of extinction-induced behavior, glances toward the cue-lights (sign tracking) are an index of resistance to extinction. Results Exp. 2: (a) As in Exp. 1, during a 30-min period of cued reward delivery, DA levels again increased significantly in the NAc core but not in the NAc shell. (b) When extinction (the absence of reward with the cue lights presented) was administered 24h after the last reward session, DA again significantly decreased in the NAc core, but not in the NAc shell. (a) These results confirm the importance of DA release in the NAc for

  18. The influence of mortality and socioeconomic status on risk and delayed rewards: a replication with British participants

    Directory of Open Access Journals (Sweden)

    Gillian V. Pepper

    2017-07-01

    Full Text Available Here, we report three attempts to replicate a finding from an influential psychological study (Griskevicius et al., 2011b. The original study found interactions between childhood SES and experimental mortality-priming condition in predicting risk acceptance and delay discounting outcomes. The original study used US student samples. We used British university students (replication 1 and British online samples (replications 2 and 3 with a modified version of the original priming material, which was tailored to make it more credible to a British audience. We did not replicate the interaction between childhood SES and mortality-priming condition in any of our three experiments. The only consistent trend of note was an interaction between sex and priming condition for delay discounting. We note that psychological priming effects are considered fragile and often fail to replicate. Our failure to replicate the original finding could be due to demographic differences in study participants, alterations made to the prime, or other study limitations. However, it is also possible that the previously reported interaction is not a robust or generalizable finding.

  19. Discounting Behavior

    DEFF Research Database (Denmark)

    Andersen, Steffen; Harrison, Glenn W.; Lau, Morten

    2014-01-01

    We re-evaluate the theory, experimental design and econometrics behind claims that individuals exhibit non-constant discounting behavior. Theory points to the importance of controlling for the non-linearity of the utility function of individuals, since the discount rate is defined over time-dated...

  20. The anticipation and outcome phases of reward and loss processing: A neuroimaging meta-analysis of the monetary incentive delay task.

    Science.gov (United States)

    Oldham, Stuart; Murawski, Carsten; Fornito, Alex; Youssef, George; Yücel, Murat; Lorenzetti, Valentina

    2018-04-25

    The processing of rewards and losses are crucial to everyday functioning. Considerable interest has been attached to investigating the anticipation and outcome phases of reward and loss processing, but results to date have been inconsistent. It is unclear if anticipation and outcome of a reward or loss recruit similar or distinct brain regions. In particular, while the striatum has widely been found to be active when anticipating a reward, whether it activates in response to the anticipation of losses as well remains ambiguous. Furthermore, concerning the orbitofrontal/ventromedial prefrontal regions, activation is often observed during reward receipt. However, it is unclear if this area is active during reward anticipation as well. We ran an Activation Likelihood Estimation meta-analysis of 50 fMRI studies, which used the Monetary Incentive Delay Task (MIDT), to identify which brain regions are implicated in the anticipation of rewards, anticipation of losses, and the receipt of reward. Anticipating rewards and losses recruits overlapping areas including the striatum, insula, amygdala and thalamus, suggesting that a generalised neural system initiates motivational processes independent of valence. The orbitofrontal/ventromedial prefrontal regions were recruited only during the reward outcome, likely representing the value of the reward received. Our findings help to clarify the neural substrates of the different phases of reward and loss processing, and advance neurobiological models of these processes. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  1. Effects of High Frequency Repeated Transcranial Magnetic Stimulation and Continuous Theta Burst Stimulation on Gambling Reinforcement, Delay Discounting, and Stroop Interference in Men with Pathological Gambling.

    Science.gov (United States)

    Zack, Martin; Cho, Sang Soo; Parlee, Jennifer; Jacobs, Mark; Li, Crystal; Boileau, Isabelle; Strafella, Antonio

    Repeated transcranial magnetic stimulation (rTMS) can reduce cravings and improve cognitive function in substance dependent individuals. Whether these benefits extend to individuals with pathological gambling (PG) is unclear. High-frequency rTMS of the medial prefrontal cortex (PFC) and continuous theta burst stimulation (cTBS) of the right dorsolateral PFC can reduce impulsive choice in healthy volunteers. This study aimed to assess the effects of these two protocols on gambling reinforcement and related responses in otherwise healthy men with PG. Participants (n = 9) underwent active or sham treatments at weekly intervals in a repeated-measures, Latin square design. Subjective and physiological responses were assessed before and after a 15-min slot machine game on each session. Delay discounting and Stroop tasks measured post-game impulsive choice and attentional control. Multivariate analysis of covariance, controlling for winnings on the slot machine under each treatment, found that rTMS reduced the post-game increase in Desire to Gamble; cTBS reduced amphetamine-like effects, and decreased diastolic blood pressure. Treatment had no significant univariate effects on bet size or speed of play in the game; however, a multivariate effect for the two indices suggested that treatment decreased behavioral activation. Neither treatment reduced impulsive choice, while both treatments increased Stroop interference. rTMS and cTBS can reduce gambling reinforcement in non-comorbid men with PG. Separate processes appear to mediate gambling reinforcement and betting behavior as against delay discounting and Stroop interference. Interventions that modify risky as opposed to temporal aspects of decision making may better predict therapeutic response in PG. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Koffarnus, Mikhail N; Woods, James H

    2013-01-01

    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. © 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.

  3. Reward processing and intertemporal decision making in adults and adolescents: the role of impulsivity and decision consistency.

    Science.gov (United States)

    Ripke, Stephan; Hübner, Thomas; Mennigen, Eva; Müller, Kathrin U; Rodehacke, Sarah; Schmidt, Dirk; Jacob, Mark J; Smolka, Michael N

    2012-10-10

    Several studies report differences between adults and adolescents in reward processing and impulsivity. Consistently, adolescents are more impulsive in their decision making, as measured by intertemporal choice tasks. Since impulsivity affects an individual's perception and neural processing of rewards, it is unclear whether previously reported differences in brain activation between adults and adolescents are primarily due to maturation of the brain reward system or differences in impulsivity (i.e. discounting behaviour). To disentangle this, we analysed data from 235 adolescents and 29 adults who performed an intertemporal choice task in which monetary rewards were adapted to individual impulsivity. Using functional magnetic resonance imaging (fMRI), we measured brain activity and assessed impulsivity and consistency of choices at the behavioural level. Although adolescents discounted delayed rewards more steeply than adults, when controlling for impulsivity, neural processing of reward value did not differ between groups. However, more impulsive subjects showed a lower brain response to delayed rewards, independent of age. Concerning decision making, adolescents exhibited a lower consistency of choices and less brain activity in the parietal network than adults. We conclude that processing of the value of prospective delayed rewards is more sensitive to discounting behaviour than to chronological age. Lower consistency of intertemporal choices might indicate ongoing maturation of parietal brain areas in adolescents. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Beyond discounting: possible experimental models of impulse control.

    Science.gov (United States)

    Monterosso, J; Ainslie, G

    1999-10-01

    Animal studies of impulsivity have typically used one of three models: a delay of reward procedure, a differential reinforcement for low rate responding (DRL) procedure, or an autoshaping procedure. In each of these paradigms, we argue, measurement of impulsivity is implicitly or explicitly equated with the effect delay has on the value of reward. The steepness by which delay diminishes value (the temporal discount function) is treated as an index of impulsivity. In order to provide a better analog of human impulsivity, this model needs to be expanded to include the converse of impulsivity - self-control. Through mechanisms such as committing to long range interests before the onset of temptation, or through bundling individual choices into classes of choices that are made at once, human decision-making can often look far less myopic than single trial experiments predict. For people, impulsive behavior may be more often the result of the breakdown of self-control mechanisms than of steep discount functions. Existing animal models of self-control are discussed, and future directions are suggested for psychopharmacological research.

  5. The effects of working memory load and attention refocusing on delay discounting rates in alcohol use disorder with comorbid antisocial personality disorder.

    Science.gov (United States)

    Gunn, Rachel L; Gerst, Kyle R; Lake, Allison J; Finn, Peter R

    2018-02-01

    Executive working memory capacity (eWMC) is central to adaptive decision-making. Research has revealed reduced eWMC and higher rates of impulsive decision making in individuals with alcohol use disorders (AUDs: DSM-IV Alcohol Dependence of Alcohol Abuse) and antisocial psychopathology (AP). Recent work has shown that placing a load on working memory (WM) further increases impulsive decision making on the delay discounting (DD) task in those with AUDs and AP. The current study examined the effects of an attention refocusing manipulation to offset the effects of this WM-load on DD rates in control subjects, those with AUDs without AP, and AUDs with AP (AUD-AP). Results revealed that 1) the AUD-AP group had higher DD rates (i.e., more impulsive decision-making) than the AUD group, followed by controls, and 2) attention refocusing after a load is placed on WM was associated with lower DD rates compared to the load without refocusing in both AUD groups, but not controls. Results suggest that refocusing attention after a cognitive load may be an effective cognitive strategy for reducing the impulsivity-enhancing effects of cognitive load on decision making in individuals with AUDs and AP. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Risk, reward, and decision-making in a rodent model of cognitive aging.

    Science.gov (United States)

    Gilbert, Ryan J; Mitchell, Marci R; Simon, Nicholas W; Bañuelos, Cristina; Setlow, Barry; Bizon, Jennifer L

    2011-01-01

    Impaired decision-making in aging can directly impact factors (financial security, health care) that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 months) and aged (23-25 months) male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (one food pellet) and a large but uncertain reward (two food pellets with varying probabilities of delivery ranging from 100 to 0%). Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the small but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was also certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for reward costs (i.e., delay or probability). These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct mechanisms that can impact cost-benefit decision-making.

  7. Intergenerational discounting

    International Nuclear Information System (INIS)

    Schelling, T.C.

    1995-01-01

    A ''discount rate'' for the consumption of future generations from current investments for their benefit is typically composed of two parts: ''time preference'' and an allowance for the lower marginal utility of consumption due to higher average levels of consumption in the future. Time preference would be involved if one were postponing one's own consumption; it has little or nothing to do with income redistribution, which is what greenhouse abatement is about. A lower marginal utility of consumption is an anomaly in income redistribution: we rarely deliberately transfer consumption from the less to the more well-to-do. Time may serve as a kind of measure of distance; we may prefer beneficiaries who are closer in time, in geographical distance, in culture, surely in kinship. Perhaps to keep our thinking straight we should use a term like ''depreciation'', rather than ''discounting''. (Author)

  8. Activity in dlPFC and its effective connectivity to vmPFC are associated with temporal discounting

    Directory of Open Access Journals (Sweden)

    Todd A Hare

    2014-03-01

    Full Text Available There is widespread interest in identifying computational and neurobiological mechanisms that influence the ability to choose long-term benefits over more proximal and readily available rewards in domains such as dietary and economic choice. We present the results of a human fMRI study that examines how neural activity relates to observed individual differences in the discounting of future rewards during an intertemporal monetary choice task. We found that a region of left dlPFC BA-46 was more active in trials where subjects chose delayed rewards, after controlling for the subjective value of those rewards. We also found that the connectivity from dlPFC BA-46 to a region of vmPFC widely associated with the computational of stimulus values, increased at the time of choice, and especially during trials in which subjects chose delayed rewards. Finally, we found that estimates of effective connectivity between these two regions played a critical role in predicting out-of-sample, between-subject differences in discount rates. Together with previous findings in dietary choice, these results suggest that a common set of computational and neurobiological mechanisms facilitate choices in favor of long- term reward in both settings.

  9. Orbitofrontal reward sensitivity and impulsivity in adult attention deficit hyperactivity disorder.

    Science.gov (United States)

    Wilbertz, Gregor; van Elst, Ludger Tebartz; Delgado, Mauricio R; Maier, Simon; Feige, Bernd; Philipsen, Alexandra; Blechert, Jens

    2012-03-01

    Impulsivity symptoms of adult attention deficit hyperactivity disorder (ADHD) such as increased risk taking have been linked with impaired reward processing. Previous studies have focused on reward anticipation or on rewarded executive functioning tasks and have described a striatal hyporesponsiveness and orbitofrontal alterations in adult and adolescent ADHD. Passive reward delivery and its link to behavioral impulsivity are less well understood. To study this crucial aspect of reward processing we used functional magnetic resonance imaging (fMRI) combined with electrodermal assessment in male and female adult ADHD patients (N=28) and matched healthy control participants (N=28) during delivery of monetary and non-monetary rewards. Further, two behavioral tasks assessed risky decision making (game of dice task) and delay discounting. Results indicated that both groups activated ventral and dorsal striatum and the medial orbitofrontal cortex (mOFC) in response to high-incentive (i.e. monetary) rewards. A similar, albeit less strong activation pattern was found for low-incentive (i.e. non-monetary) rewards. Group differences emerged when comparing high and low incentive rewards directly: activation in the mOFC coded for the motivational change in reward delivery in healthy controls, but not ADHD patients. Additionally, this dysfunctional mOFC activity in patients correlated with risky decision making and delay discounting and was paralleled by physiological arousal. Together, these results suggest that the mOFC codes reward value and type in healthy individuals whereas this function is deficient in ADHD. The brain-behavior correlations suggest that this deficit might be related to behavioral impulsivity. Reward value processing difficulties in ADHD should be considered when assessing reward anticipation and emotional learning in research and applied settings. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Risk, reward, and decision-making in a rodent model of cognitive aging

    Directory of Open Access Journals (Sweden)

    Ryan J Gilbert

    2012-01-01

    Full Text Available Impaired decision-making in aging can directly impact factors (financial security, quality of healthcare that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 mo. and aged (23-25 mo. male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (1 food pellet and a large but uncertain reward (2 food pellets with varying probabilities of delivery ranging from 100% to 0%. Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the smaller but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for costs (i.e., delay, probability. These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct neural mechanisms that can impact cost

  11. Temporal Discounting Is Associated with an Increased Risk of Mortality among Community-Based Older Persons without Dementia.

    Directory of Open Access Journals (Sweden)

    Patricia A Boyle

    Full Text Available Temporal discounting is an important determinant of many health and financial outcomes, but we are not aware of studies that have examined the association of temporal discounting with mortality.Participants were 406 older persons without dementia from the Rush Memory and Aging Project, a longitudinal cohort study of aging. Temporal discounting was measured using standard preference elicitation questions. Individual discount rates were estimated using a well-established hyperbolic function and used to predict the risk of mortality during up to 5 years of follow-up.The mean estimate of discounting was 0.45 (SD = 0.33, range: 0.08-0.90, with higher scores indicating a greater propensity to prefer smaller immediate rewards over larger but delayed ones. During up to 5 years of follow-up (mean = 3.6 years, 62 (15% of 406 persons died. In a proportional hazards model adjusted for age, sex, and education, temporal discounting was associated with an increased risk of mortality (HR = 1.103, 95% CI 1.024, 1.190, p = 0.010. Thus, a person with the highest discount rate (score = 0.90 was about twice more likely to die over the study period compared to a person with the lowest discount rate (score = 0.08. Further, the association of discounting with mortality persisted after adjustment for the level of global cognitive function, the burden of vascular risk factors and diseases, and an indicator of psychological well being (i.e., purpose in life.Temporal discounting is associated with an increased risk of mortality in old age after accounting for global cognitive function and indicators of physical and mental health.

  12. Gratitude intervention modulates P3 amplitude in a temporal discounting task.

    Science.gov (United States)

    Patalano, Andrea L; Lolli, Sydney L; Sanislow, Charles A

    2018-06-23

    Gratitude has been shown to reduce economic impatience. In particular, individuals induced to experience heightened gratitude are more willing to choose delayed larger rewards over immediate smaller rewards (i.e., they have lower discounting rates) than those in a neutral condition. Using the event-related potential (ERP) method, we investigated the relation between gratitude level and neurophysiological correlates. Of interest was motivated information processing, as indexed by the P3 component. Participants were administered a gratitude or a neutral mood induction followed by a temporal discounting task (choosing between a fixed immediate reward versus a future reward that varied across trials) while electroencephalogram (EEG) activity was recorded. Individuals in the gratitude condition had greater P3 amplitude, suggesting greater attention to the future-reward option (the choice option that varied across trials), even when this option was not selected, and providing the first evidence of gratitude-induced changes in electrophysiological activity. Copyright © 2018. Published by Elsevier B.V.

  13. BIS impulsivity and acute nicotine exposure are associated with discounting global consequences in the Harvard game.

    Science.gov (United States)

    Hogarth, Lee; Stillwell, David J; Tunney, Richard J

    2013-01-01

    The Barratt Impulsivity Scale (BIS) provides a transdiagnostic marker for a number of psychiatric conditions and drug abuse, but the precise psychological trait(s) tapped by this questionnaire remain obscure. To address this, 51 smokers completed in counterbalanced order the BIS, a delay discounting task and a Harvard game that measured choice between a response that yielded a high immediate monetary payoff but decreased opportunity to earn money overall (local choice) versus a response that yielded a lower immediate payoff but afforded a greater opportunity to earn overall (global choice). Individual level of BIS impulsivity and self-elected smoking prior to the study were independently associated with increased preference for the local over the global choice in the Harvard game, but not delay discounting. BIS impulsivity and acute nicotine exposure reflect a bias in the governance of choice by immediate reward contingencies over global consequences, consistent with contemporary dual-process instrumental learning theories. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Temporal discounting and emotional self-regulation in children with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Utsumi, Daniel Augusto; Miranda, Mônica Carolina; Muszkat, Mauro

    2016-12-30

    Temporal Discounting (TD) reflects a tendency to discount a reward more deeply the longer its delivery is delayed. TD tasks and behavioral scales have been used to investigate 'hot' executive functions in ADHD. The present study analyzed TD task performance shown by ADHD and control groups for correlations with emotional self-regulation metrics from two scales, the Behavior Rating Inventory of Executive Functions (BRIEF) and the Child Behavior Checklist (CBCL). Children (ages 8-12) with ADHD (n=25) and controls (n=24) were assessed using material rewards (toys) for three types of task: Hypothetical (H); Hypothetical with temporal expectation (HTE); and Real (R). Between-group differences were found for the HTE task, on which the ADHD group showed a higher rate of discounting their favorite toy over time, especially at 10s and 20s. This was the only task on which performance significantly correlated with BRIEF metrics, thus suggesting associations between impulsivity and low emotional self-regulation, but no task was correlated with CBCL score. The conclusion is that tasks involving toys and HTE in particular may be used to investigate TD in children with ADHD and as a means of evaluating the interface between the reward system and emotional self-regulation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Victims' time discounting 2.5 years after the Wenchuan earthquake: an ERP study.

    Directory of Open Access Journals (Sweden)

    Jin-Zhen Li

    Full Text Available Time discounting refers to the fact that the subjective value of a reward decreases as the delay until its occurrence increases. The present study investigated how time discounting has been affected in survivors of the magnitude-8.0 Wenchuan earthquake that occurred in China in 2008.Nineteen earthquake survivors and 22 controls, all school teachers, participated in the study. Event-related brain potentials (ERPs for time discounting tasks involving gains and losses were acquired in both the victims and controls.The behavioral data replicated our previous findings that delayed gains were discounted more steeply after a disaster. ERP results revealed that the P200 and P300 amplitudes were increased in earthquake survivors. There was a significant group (earthquake vs. non-earthquake × task (gain vs. loss interaction for the N300 amplitude, with a marginally significantly reduced N300 for gain tasks in the experimental group, which may suggest a deficiency in inhibitory control for gains among victims.The results suggest that post-disaster decisions might involve more emotional (System 1 and less rational thinking (System 2 in terms of a dual-process model of decision making. The implications for post-disaster intervention and management are also discussed.

  16. Victims' time discounting 2.5 years after the Wenchuan earthquake: an ERP study.

    Science.gov (United States)

    Li, Jin-Zhen; Gui, Dan-Yang; Feng, Chun-Liang; Wang, Wen-Zhong; Du, Bo-Qi; Gan, Tian; Luo, Yue-Jia

    2012-01-01

    Time discounting refers to the fact that the subjective value of a reward decreases as the delay until its occurrence increases. The present study investigated how time discounting has been affected in survivors of the magnitude-8.0 Wenchuan earthquake that occurred in China in 2008. Nineteen earthquake survivors and 22 controls, all school teachers, participated in the study. Event-related brain potentials (ERPs) for time discounting tasks involving gains and losses were acquired in both the victims and controls. The behavioral data replicated our previous findings that delayed gains were discounted more steeply after a disaster. ERP results revealed that the P200 and P300 amplitudes were increased in earthquake survivors. There was a significant group (earthquake vs. non-earthquake) × task (gain vs. loss) interaction for the N300 amplitude, with a marginally significantly reduced N300 for gain tasks in the experimental group, which may suggest a deficiency in inhibitory control for gains among victims. The results suggest that post-disaster decisions might involve more emotional (System 1) and less rational thinking (System 2) in terms of a dual-process model of decision making. The implications for post-disaster intervention and management are also discussed.

  17. The effects of HIV-1 regulatory TAT protein expression on brain reward function, response to psychostimulants and delay-dependent memory in mice.

    Science.gov (United States)

    Kesby, James P; Markou, Athina; Semenova, Svetlana

    2016-10-01

    Depression and psychostimulant abuse are common comorbidities among humans with immunodeficiency virus (HIV) disease. The HIV regulatory protein TAT is one of multiple HIV-related proteins associated with HIV-induced neurotoxicity. TAT-induced dysfunction of dopamine and serotonin systems in corticolimbic brain areas may result in impaired reward function, thus, contributing to depressive symptoms and psychostimulant abuse. Transgenic mice with doxycycline-induced TAT protein expression in the brain (TAT+, TAT- control) show neuropathology resembling brain abnormalities in HIV+ humans. We evaluated brain reward function in response to TAT expression, nicotine and methamphetamine administration in TAT+ and TAT- mice using the intracranial self-stimulation procedure. We evaluated the brain dopamine and serotonin systems with high-performance liquid chromatography. The effects of TAT expression on delay-dependent working memory in TAT+ and TAT- mice using the operant delayed nonmatch-to-position task were also assessed. During doxycycline administration, reward thresholds were elevated by 20% in TAT+ mice compared with TAT- mice. After the termination of doxycycline treatment, thresholds of TAT+ mice remained significantly higher than those of TAT- mice and this was associated with changes in mesolimbic serotonin and dopamine levels. TAT+ mice showed a greater methamphetamine-induced threshold lowering compared with TAT- mice. TAT expression did not alter delay-dependent working memory. These results indicate that TAT expression in mice leads to reward deficits, a core symptom of depression, and a greater sensitivity to methamphetamine-induced reward enhancement. Our findings suggest that the TAT protein may contribute to increased depressive-like symptoms and continued methamphetamine use in HIV-positive individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Unhealthy diets, obesity and time discounting: a systematic literature review and network analysis.

    Science.gov (United States)

    Barlow, Pepita; Reeves, Aaron; McKee, Martin; Galea, Gauden; Stuckler, David

    2016-09-01

    There is an increasing policy commitment to address the avoidable burdens of unhealthy diet, overweight and obesity. However, to design effective policies, it is important to understand why people make unhealthy dietary choices. Research from behavioural economics suggests a critical role for time discounting, which describes how people's value of a reward, such as better health, decreases with delay to its receipt. We systematically reviewed the literature on the relationship of time discounting with unhealthy diets, overweight and obesity in Web of Science and PubMed. We identified 41 studies that met our inclusion criteria as they examined the association between time discount rates and (i) unhealthy food consumption; (ii) overweight and (iii) response to dietary and weight loss interventions. Nineteen out of 25 cross-sectional studies found time discount rates positively associated with overweight, obesity and unhealthy diets. Experimental studies indicated that lower time discounting was associated with greater weight loss. Findings varied by how time discount rates were measured; stronger results were observed for food than monetary-based measurements. Network co-citation analysis revealed a concentration of research in nutrition journals. Overall, there is moderate evidence that high time discounting is a significant risk factor for unhealthy diets, overweight and obesity and may serve as an important target for intervention. © 2016 The Authors Obesity Reviews published by John Wiley & Sons Ltd on behalf of International Association for the Study of Obesity (IASO). © 2016 The Authors Obesity Reviews published by John Wiley & Sons Ltd on behalf of International Association for the Study of Obesity (IASO).

  19. The delay effect on outcome evaluation: results from an Event-related Potential study

    Directory of Open Access Journals (Sweden)

    Chen eQu

    2013-11-01

    Full Text Available Behavioral studies demonstrate that the timing of receiving gains or losses affects decision-making, a phenomenon known as temporal discounting, as participants are inclined to prefer immediate rewards over delayed ones and vice versa for losses. The present study used the event-related potential (ERP technique with a simple gambling task to investigate how delayed rewards and losses affected the brain activity in outcome evaluations made by 20 young adults. Statistical analysis revealed a larger feedback related negativity (FRN effect between loss and gain following immediate outcomes than following future outcomes. In addition, delay impacted FRN only in gain conditions, with delayed winning eliciting a more negative FRN than immediatewinning. These results suggest that temporal discounting and sign effect could be encoded in the FRN in the early stage of outcome evaluation.

  20. Separate valuation subsystems for delay and effort decision costs.

    Science.gov (United States)

    Prévost, Charlotte; Pessiglione, Mathias; Météreau, Elise; Cléry-Melin, Marie-Laure; Dreher, Jean-Claude

    2010-10-20

    Decision making consists of choosing among available options on the basis of a valuation of their potential costs and benefits. Most theoretical models of decision making in behavioral economics, psychology, and computer science propose that the desirability of outcomes expected from alternative options can be quantified by utility functions. These utility functions allow a decision maker to assign subjective values to each option under consideration by weighting the likely benefits and costs resulting from an action and to select the one with the highest subjective value. Here, we used model-based neuroimaging to test whether the human brain uses separate valuation systems for rewards (erotic stimuli) associated with different types of costs, namely, delay and effort. We show that humans devalue rewards associated with physical effort in a strikingly similar fashion to those they devalue that are associated with delays, and that a single computational model derived from economics theory can account for the behavior observed in both delay discounting and effort discounting. However, our neuroimaging data reveal that the human brain uses distinct valuation subsystems for different types of costs, reflecting in opposite fashion delayed reward and future energetic expenses. The ventral striatum and the ventromedial prefrontal cortex represent the increasing subjective value of delayed rewards, whereas a distinct network, composed of the anterior cingulate cortex and the anterior insula, represent the decreasing value of the effortful option, coding the expected expense of energy. Together, these data demonstrate that the valuation processes underlying different types of costs can be fractionated at the cerebral level.

  1. On multiple discount rates

    OpenAIRE

    Chambers, Christopher P.; Echenique, Federico

    2016-01-01

    We propose a theory of intertemporal choice that is robust to specific assumptions on the discount rate. One class of models requires that one utility stream be chosen over another if and only if its discounted value is higher for all discount factors in a set. Another model focuses on an average discount factor. Yet another model is pessimistic, and evaluates a flow by the lowest available discounted value.

  2. Incidental rewarding cues influence economic decisions in people with obesity

    Science.gov (United States)

    Simmank, Jakob; Murawski, Carsten; Bode, Stefan; Horstmann, Annette

    2015-01-01

    Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n = 52) completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discount rates. Additionally, participants were primed by affective visual cues of different contextual categories before making financial decisions. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity toward changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short. PMID:26528158

  3. Incidental rewarding cues influence economic decision-making in obesity

    Directory of Open Access Journals (Sweden)

    Jakob eSimmank

    2015-10-01

    Full Text Available Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n=52 completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discounting rates. Additionally, participants were primed by affective visual cues of different contextual categories before the financial decision. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity towards changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short.

  4. Discounting in Economic Evaluations.

    Science.gov (United States)

    Attema, Arthur E; Brouwer, Werner B F; Claxton, Karl

    2018-05-19

    Appropriate discounting rules in economic evaluations have received considerable attention in the literature and in national guidelines for economic evaluations. Rightfully so, as discounting can be quite influential on the outcomes of economic evaluations. The most prominent controversies regarding discounting involve the basis for and height of the discount rate, whether costs and effects should be discounted at the same rate, and whether discount rates should decline or stay constant over time. Moreover, the choice for discount rules depends on the decision context one adopts as the most relevant. In this article, we review these issues and debates, and describe and discuss the current discounting recommendations of the countries publishing their national guidelines. We finish the article by proposing a research agenda.

  5. Discounting and nuclear power

    International Nuclear Information System (INIS)

    Jones, P.M.S.

    1984-01-01

    The paper describes the practice of discounting and its applicability to nuclear power, and the choice of discount rates. Opportunity cost of capital; risk; social time preference; intergenerational equity; non-monetary aspects; and discounting and nuclear energy; are all discussed. (U.K.)

  6. Do the Powerful Discount the Future Less? The Effects of Power on Temporal Discounting.

    Science.gov (United States)

    Duan, Jinyun; Wu, Sherry J; Sun, Luying

    2017-01-01

    Individuals have the tendency to discount rewards in the future, known as temporal discounting, and we find that sense of power (the felt capacity to influence the thinking and behavior of others) reduces such tendency. In Studies 1 and 2, we used both an experiment and a survey with organizational employees to demonstrate that power reduced temporal discounting. In Study 3, we replicated study 1 while exploring a unique cultural trait of Danbo , or indifference to fame and wealth, across two ethnic groups (Han and Tibetan groups) in China. While power reduces temporal discounting, the relationship between the two may be leveraged by individual differences of optimism, frustration, and Danbo . The results imply a more nuanced interpretation of how individual and situational factors can affect intertemporal choice.

  7. Can we use human judgments to determine the discount rate?

    Science.gov (United States)

    Baron, J

    2000-12-01

    It has been suggested that the long-term discount rate for environmental goods should decrease at longer delays. One justification for this suggestion is that human judgments support it. This article presents an experiment showing that judgments concerning discount rates are internally inconsistent. These results point to potential problems with the use of judgments referenda for determining discount rates in cost-benefit analyses.

  8. Discounted Duration Calculus

    DEFF Research Database (Denmark)

    Ody, Heinrich; Fränzle, Martin; Hansen, Michael Reichhardt

    2016-01-01

    To formally reason about the temporal quality of systems discounting was introduced to CTL and LTL. However, these logic are discrete and they cannot express duration properties. In this work we introduce discounting for a variant of Duration Calculus. We prove decidability of model checking...... for a useful fragment of discounted Duration Calculus formulas on timed automata under mild assumptions. Further, we provide an extensive example to show the usefulness of the fragment....

  9. Discounting and Expropriation Risk

    OpenAIRE

    Giovanni Immordino; Mario Padula

    2007-01-01

    This paper investigates the association between discounting and risk of expropriation and provides the theoretical conditions that make a positive association consistent with rationality. Moreover, using a national representative sample and a representative sample of the 50+ in eleven European countries, we show that discounting increases with expropriation risk. The two surveys give direct measures of discount rate as well as measures derived from households consumption decisions and provide...

  10. Discounting in Time

    DEFF Research Database (Denmark)

    Fahrenberg, Uli; Larsen, Kim Guldstrand

    2009-01-01

    This paper deals with the issue of discounting in weighted timed transition systems. Discounting provides a way to model optimal-cost problems for infinite runs and has applications in optimal scheduling and other areas. We show that when postulating a certain natural additivity property for the ......This paper deals with the issue of discounting in weighted timed transition systems. Discounting provides a way to model optimal-cost problems for infinite runs and has applications in optimal scheduling and other areas. We show that when postulating a certain natural additivity property...

  11. Balancing risk and reward: a rat model of risky decision making.

    Science.gov (United States)

    Simon, Nicholas W; Gilbert, Ryan J; Mayse, Jeffrey D; Bizon, Jennifer L; Setlow, Barry

    2009-09-01

    We developed a behavioral task in rats to assess the influence of risk of punishment on decision making. Male Long-Evans rats were given choices between pressing a lever to obtain a small, 'safe' food reward and a large food reward associated with risk of punishment (footshock). Each test session consisted of 5 blocks of 10 choice trials, with punishment risk increasing with each consecutive block (0, 25, 50, 75, 100%). Preference for the large, 'risky' reward declined with both increased probability and increased magnitude of punishment, and reward choice was not affected by the level of satiation or the order of risk presentation. Performance in this risky decision-making task was correlated with the degree to which the rats discounted the value of probabilistic rewards, but not delayed rewards. Finally, the acute effects of different doses of amphetamine and cocaine on risky decision making were assessed. Systemic amphetamine administration caused a dose-dependent decrease in choice of the large risky reward (ie, it made rats more risk averse). Cocaine did not cause a shift in reward choice, but instead impaired the rats' sensitivity to changes in punishment risk. These results should prove useful for investigating neuropsychiatric disorders in which risk taking is a prominent feature, such as attention deficit/hyperactivity disorder and addiction.

  12. Monetary discounting and ventral striatal dopamine receptor availability in nontreatment-seeking alcoholics and social drinkers.

    Science.gov (United States)

    Oberlin, Brandon G; Albrecht, Daniel S; Herring, Christine M; Walters, James W; Hile, Karen L; Kareken, David A; Yoder, Karmen K

    2015-06-01

    Dopamine (DA) in the ventral striatum (VST) has long been implicated in addiction pathologies, yet its role in temporal decision-making is not well-understood. To determine if VST DA D2 receptor availability corresponds with greater impulsive choice in both nontreatment-seeking alcoholics (NTS) and social drinkers (SD). NTS subjects (n = 10) and SD (n = 13) received PET scans at baseline with the D2/D3 radioligand [(11)C]raclopride (RAC). Outside the scanner, subjects performed a delay discounting procedure with monetary rewards. RAC binding potential (BPND) was estimated voxelwise, and correlations were performed to test for relationships between VST BPND and delay discounting performance. Self-reported impulsivity was also tested for correlations with BPND. Across all subjects, greater impulsive choice for $20 correlated with lower BPND in the right VST. NTS showed greater impulsive choice than SD and were more impulsive by self-report. Across all subjects, the capacity of larger rewards to reduce impulsive choice (the magnitude effect) correlated negatively (p = 0.028) with problematic alcohol use (AUDIT) scores. Self-reported impulsivity did not correlate with BPND in VST. Preference for immediate reinforcement may reflect greater endogenous striatal DA or lower D2 number, or both. Alcoholic status did not mediate significant effects on VST BPND, suggesting minimal effects from alcohol exposure. The apparent lack of BPND correlation with self-reported impulsivity highlights the need for objective behavioral assays in the study of the neurochemical substrates of behavior. Finally, our results suggest that the magnitude effect may be more sensitive to alcohol-induced problems than single discounting measures.

  13. Mobile technology habits: patterns of association among device usage, intertemporal preference, impulse control, and reward sensitivity.

    Science.gov (United States)

    Wilmer, Henry H; Chein, Jason M

    2016-10-01

    Mobile electronic devices are playing an increasingly pervasive role in our daily activities. Yet, there has been very little empirical research investigating how mobile technology habits might relate to individual differences in cognition and affect. The research presented in this paper provides evidence that heavier investment in mobile devices is correlated with a relatively weaker tendency to delay gratification (as measured by a delay discounting task) and a greater inclination toward impulsive behavior (i.e., weaker impulse control, assessed behaviorally and through self-report) but is not related to individual differences in sensitivity to reward. Analyses further demonstrated that individual variation in impulse control mediates the relationship between mobile technology usage and delay of gratification. Although based on correlational results, these findings lend some backing to concerns that increased use of portable electronic devices could have negative impacts on impulse control and the ability to appropriately valuate delayed rewards.

  14. Discounting of Condom-Protected Sex as a Measure of High Risk for Sexually Transmitted Infection Among College Students.

    Science.gov (United States)

    Collado, Anahí; Johnson, Patrick S; Loya, Jennifer M; Johnson, Matthew W; Yi, Richard

    2017-10-01

    The study examined sexual delay discounting, or the devaluation of condom-protected sex in the face of delay, as a risk factor for sexually transmitted infection (STI) among college students. Participants (143 females, 117 males) completed the sexual delay discounting task (Johnson & Bruner, 2012) and questionnaires of risky sexual behavior, risk perception, and knowledge. Participants exhibited steeper sexual delay discounting (above and beyond general likelihood of having unprotected sex) when partners were viewed as more desirable or less likely to have a STI, with males demonstrating greater sexual delay discounting than females across most conditions. Importantly, greater self-reported risky sexual behaviors were associated with higher rates of sexual delay discounting, but not with likelihood of using a condom in the absence of delay. These results provide support for considering sexual delay discounting, with particular emphasis on potential delays to condom use, as a risk factor for STI among college students.

  15. The impact of Parkinson's disease and subthalamic deep brain stimulation on reward processing.

    Science.gov (United States)

    Evens, Ricarda; Stankevich, Yuliya; Dshemuchadse, Maja; Storch, Alexander; Wolz, Martin; Reichmann, Heinz; Schlaepfer, Thomas E; Goschke, Thomas; Lueken, Ulrike

    2015-08-01

    Due to its position in cortico-subthalamic and cortico-striatal pathways, the subthalamic nucleus (STN) is considered to play a crucial role not only in motor, but also in cognitive and motivational functions. In the present study we aimed to characterize how different aspects of reward processing are affected by disease and deep brain stimulation of the STN (DBS-STN) in patients with idiopathic Parkinson's disease (PD). We compared 33 PD patients treated with DBS-STN under best medical treatment (DBS-on, medication-on) to 33 PD patients without DBS, but optimized pharmacological treatment and 34 age-matched healthy controls. We then investigated DBS-STN effects using a postoperative stimulation-on/ -off design. The task set included a delay discounting task, a task to assess changes in incentive salience attribution, and the Iowa Gambling Task. The presence of PD was associated with increased incentive salience attribution and devaluation of delayed rewards. Acute DBS-STN increased risky choices in the Iowa Gambling Task under DBS-on condition, but did not further affect incentive salience attribution or the evaluation of delayed rewards. Findings indicate that acute DBS-STN affects specific aspects of reward processing, including the weighting of gains and losses, while larger-scale effects of disease or medication are predominant in others reward-related functions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Reduced sensitivity to sooner reward during intertemporal decision-making following insula damage in humans

    Directory of Open Access Journals (Sweden)

    Manuela eSellitto

    2016-01-01

    Full Text Available During intertemporal choice, humans tend to prefer small-sooner rewards over larger-delayed rewards, reflecting temporal discounting (TD of delayed outcomes. Functional neuroimaging evidence has implicated the insular cortex in time-sensitive decisions, yet it is not clear whether activity in this brain region is crucial for, or merely associated with, TD behaviour. Here, patients with damage to the insula (Insular patients, control patients with lesions outside the insula, and healthy individuals chose between smaller-sooner and larger-later monetary rewards. Insular patients were less sensitive to sooner rewards than were the control groups, exhibiting reduced TD. A Voxel-based Lesion-Symptom Mapping (VLSM analysis confirmed a statistically significant association between insular damage and reduced TD. These results indicate that the insular cortex is crucial for intertemporal choice. We suggest that he insula may be necessary to anticipate the bodily/emotional effects of receiving rewards at different delays, influencing the computation of their incentive value. Devoid of such input, insular patients’ choices would be governed by a heuristic of quantity, allowing patients to wait for larger options.

  17. The Contrast Effect in Temporal and Probabilistic Discounting

    Science.gov (United States)

    Chen, Cheng; He, Guibing

    2016-01-01

    In this information age, messages related to time, and uncertainty surround us. At the same time, our daily lives are filled with decisions accompanied by temporal delay or uncertainty. Will such information influence our temporal and probabilistic discounting? The authors address this question from the perspectives of decision by sampling (DbS) theory and psychological distance theory. Studies 1 and 2 investigated the effect of contextual messages on temporal discounting and probabilistic discounting, respectively. The results indicated that participants who memorized messages about long-term and low-probability events rated delay or uncertainty as mentally closer and exhibited a less degree of value discounting than those who memorized messages regarding short-term and high-probability events. In addition, a sense of distance from present or reality mediated the effect of contextual messages on value discounting. The implications of the current findings for theory and applications are discussed. PMID:27014122

  18. Values in Time Discounting.

    Science.gov (United States)

    Heilmann, Conrad

    2017-10-01

    Controversies about time discounting loom large in decisions about climate change. Prominently, a particularly controversial debate about time discounting in climate change decision-making has been conducted within climate economics, between the authors of Stern et al. (Stern review on the economics of climate change, 2006) and their critics (most prominently Dasgupta in Comments on the Stern review's economics of climate change, 2006; Tol in Energy Environ 17(6):977-981, 2006; Weitzman in J Econ Lit XLV:703-724, 2007; Nordhaus in J Econ Lit XLV:686-702, 2007). The article examines the role of values in this debate. Firstly, it is shown that time discounting is a case in which values are key because it is at heart an ethical problem. Secondly, it is argued that time discounting in climate economics is a case of economists making frequent and routine references to ethical values and indeed conduct ethical debates with each other. Thirdly, it is argued that there is evidence for deep and pervasive entanglement between facts and values in the prevalent methodologies for time discounting. Finally, it is argued that this means that economists have given up the 'value-free ideal' concerning time discounting, and discussed how the current methodology of time discounting in economics can be improved.

  19. Hunger does not motivate reward in women remitted from anorexia nervosa.

    Science.gov (United States)

    Wierenga, Christina E; Bischoff-Grethe, Amanda; Melrose, A James; Irvine, Zoe; Torres, Laura; Bailer, Ursula F; Simmons, Alan; Fudge, Julie L; McClure, Samuel M; Ely, Alice; Kaye, Walter H

    2015-04-01

    Hunger enhances sensitivity to reward, yet individuals with anorexia nervosa (AN) are not motivated to eat when starved. This study investigated brain response to rewards during hunger and satiated states to examine whether diminished response to reward could underlie food restriction in AN. Using a delay discounting monetary decision task known to discriminate brain regions contributing to processing of immediate rewards and cognitive control important for decision making regarding future rewards, we compared 23 women remitted from AN (RAN group; to reduce the confounding effects of starvation) with 17 healthy comparison women (CW group). Monetary rewards were used because the rewarding value of food may be confounded by anxiety in AN. Interactions of Group (RAN, CW) × Visit (hunger, satiety) revealed that, for the CW group, hunger significantly increased activation in reward salience circuitry (ventral striatum, dorsal caudate, anterior cingulate cortex) during processing of immediate reward, whereas satiety increased activation in cognitive control circuitry (ventrolateral prefrontal cortex, insula) during decision making. In contrast, brain response in reward and cognitive neurocircuitry did not differ during hunger and satiety in the RAN group. A main effect of group revealed elevated response in the middle frontal gyrus for the RAN group compared with the CW group. Women remitted from AN failed to increase activation of reward valuation circuitry when hungry and showed elevated response in cognitive control circuitry independent of metabolic state. Decreased sensitivity to the motivational drive of hunger may explain the ability of individuals with AN to restrict food when emaciated. Difficulties in valuating emotional salience may contribute to inabilities to appreciate the risks inherent in this disorder. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. Positive autobiographical memory retrieval reduces temporal discounting.

    Science.gov (United States)

    Lempert, Karolina M; Speer, Megan E; Delgado, Mauricio R; Phelps, Elizabeth A

    2017-10-01

    People generally prefer rewards sooner rather than later. This phenomenon, temporal discounting, underlies many societal problems, including addiction and obesity. One way to reduce temporal discounting is to imagine positive future experiences. Since there is overlap in the neural circuitry associated with imagining future experiences and remembering past events, here we investigate whether recalling positive memories can also promote more patient choice. We found that participants were more patient after retrieving positive autobiographical memories, but not when they recalled negative memories. Moreover, individuals were more impulsive after imagining novel positive scenes that were not related to their memories, showing that positive imagery alone does not drive this effect. Activity in the striatum and temporo parietal junction during memory retrieval predicted more patient choice, suggesting that to the extent that memory recall is rewarding and involves perspective-taking, it influences decision-making. Furthermore, representational similarity in the ventromedial prefrontal cortex between memory recall and decision phases correlated with the behavioral effect across participants. Thus, we have identified a novel manipulation for reducing temporal discounting-remembering the positive past-and have begun to characterize the psychological and neural mechanisms behind it. © The Author (2017). Published by Oxford University Press.

  1. Open access discount information

    International Development Research Centre (IDRC) Digital Library (Canada)

    Lauren Doyle

    Wiley Interdisciplinary Reviews: Climate Change. Wiley offers OA in: Gold: ... International Journal of Health Services. Journal of ... Camridge University Press offers waivers and discounts based on: 1) Authors of ... based on the World Bank list.

  2. Is there time discounting for risk premium?

    Science.gov (United States)

    Shavit, Tal; Rosenboim, Mosi

    2015-03-01

    Individuals with a higher subjective discount rate concentrate more on the present and delay is more significant for them. However, when a risky asset is delayed, not only is the outcome delayed but also the risk. In this paper, we suggest a new, two-stage experimental method with real monetary incentives that allows us to distinguish between the effect of the risk and the effect of the time when pricing a risky asset. We show that when individuals have greater preference for the present, their risk aversion for a risky asset realized in the future decreases. We argue that the effect of the risk for future asset is lower for individuals with higher time preference because they discount not only the outcome but also the risks. © Society for the Experimental Analysis of Behavior.

  3. Discounting in the evaluation of the cost-effectiveness of a vaccination programme: A critical review.

    Science.gov (United States)

    Jit, Mark; Mibei, Walter

    2015-07-31

    Discounting future costs and health benefits usually has a large effect on results of cost-effectiveness evaluations of vaccination because of delays between the initial expenditure in the programme and the health benefits from averting disease. Most guidelines currently recommend discounting both costs and health effects at a positive, constant, common rate back to a common point in time. A review of 84 published economic evaluations of vaccines found that most of them apply these recommendations. However, both technical and normative arguments have been presented for discounting health at a different rate to consumption (differential discounting), discounting at a rate that changes over time (non-constant discounting), discounting intra-generational and inter-generational effects at a different rate (two-stage discounting), and discounting the health gains from an intervention to a different discount year from the time of intervention (delayed discounting). These considerations are particularly acute for vaccines, because their effects can occur in a different generation from the one paying for them, and because the time of vaccination, of infection aversion, and of disease aversion usually differ. Using differential, two-stage or delayed discounting in model-based cost-effectiveness evaluations of vaccination raises technical challenges, but mechanisms have been proposed to overcome them. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Social Discounting under Risk.

    Science.gov (United States)

    Jin, Jia; Pei, Guanxiong; Ma, Qingguo

    2017-01-01

    As a measure of how prosocial behavior depends on social distance, social discounting is defined as the decrease in generosity between the decision maker and the recipient as the social distance increases. While risk is a ubiquitous part of modern life, there is limited research on the relationship between risk and prosocial behavior. In the present experiment, we empirically test whether risk has an influence on social discounting. We use the choice titration procedure to examine this effect. Our data show that independent of risk, participants are less eager to forego money and exhibit more selfishness toward a specific person when the social distance increases; these findings are reflected in the hyperbolic model. Interestingly, risk influences the shape of the social discounting function, which is reflected in the notable different discount rates. Individuals who make decisions under risk yield a smaller discount rate than those who make decisions without risk, i.e., under risk subjects reduce less their generosity as a function of the social distance. Furthermore, this distinct type of generosity occurs typically among individuals with 10-distance recipients but not with the closest- and furthest-social-distance recipients.

  5. Belief reward shaping in reinforcement learning

    CSIR Research Space (South Africa)

    Marom, O

    2018-02-01

    Full Text Available A key challenge in many reinforcement learning problems is delayed rewards, which can significantly slow down learning. Although reward shaping has previously been introduced to accelerate learning by bootstrapping an agent with additional...

  6. Distinct age-related differences in temporal discounting and risk taking in adolescents and young adults

    NARCIS (Netherlands)

    Water, E. de; Cillessen, A.H.N.; Scheres, A.P.J.

    2014-01-01

    Age-related differences in temporal discounting (TD) and risk taking, and their association, were examined in adolescents and young adults (n=337) aged 12-27years. Since monetary rewards are typically used in TD and risk-taking tasks, the association between monetary reward valuation and age and

  7. Aggregate Social Discount Rate Derived from Individual Discount Rates

    OpenAIRE

    Kenneth F. Reinschmidt

    2002-01-01

    In the economic evaluation of large public-sector projects, an aggregate social discount rate may be used in present worth comparison of alternatives. This paper uses the assumptions that individual discount rates are constant over time and approximately Normally distributed across the affected population, with mean \\mu and variance \\sigma 2 , to derive an aggregate discount function that is exponential in form but with time-dependent aggregate discount rate \\rho (t) = \\mu - \\sigma 2 t/2, whe...

  8. Dopamine D2/3- and μ-opioid receptor antagonists reduce cue-induced responding and reward impulsivity in humans.

    Science.gov (United States)

    Weber, S C; Beck-Schimmer, B; Kajdi, M-E; Müller, D; Tobler, P N; Quednow, B B

    2016-07-05

    Increased responding to drug-associated stimuli (cue reactivity) and an inability to tolerate delayed gratification (reward impulsivity) have been implicated in the development and maintenance of drug addiction. Whereas data from animal studies suggest that both the dopamine and opioid system are involved in these two reward-related processes, their role in humans is less clear. Moreover, dopaminergic and opioidergic drugs have not been directly compared with regard to these functions, even though a deeper understanding of the underlying mechanisms might inform the development of specific treatments for elevated cue reactivity and reward impulsivity. In a randomized, double-blind, between-subject design we administered the selective dopamine D2/D3 receptor antagonist amisulpride (400 mg, n=41), the unspecific opioid receptor antagonist naltrexone (50 mg, n=40) or placebo (n=40) to healthy humans and measured cue-induced responding with a Pavlovian-instrumental transfer task and reward impulsivity with a delay discounting task. Mood was assessed using a visual analogue scale. Compared with placebo, amisulpride significantly suppressed cue-induced responding and reward impulsivity. The effects of naltrexone were similar, although less pronounced. Both amisulpride and naltrexone decreased average mood ratings compared with placebo. Our results demonstrate that a selective blockade of dopamine D2/D3 receptors reduces cue-induced responding and reward impulsivity in healthy humans. Antagonizing μ-opioid receptors has similar effects for cue-induced responding and to a lesser extent for reward impulsivity.

  9. Discounting of money and sex: effects of commodity and temporal position in stimulant-dependent men and women.

    Science.gov (United States)

    Jarmolowicz, David P; Landes, Reid D; Christensen, Darren R; Jones, Bryan A; Jackson, Lisa; Yi, Richard; Bickel, Warren K

    2014-11-01

    Research on delay discounting has contributed to the understanding of numerous addiction-related phenomena. For example, studies have shown that substance dependent individuals discount their addictive substances (e.g., cocaine) more rapidly than they do other commodities (e.g., money). Recent research has shown that substance dependent individuals discount delayed sex more rapidly than delayed money, and their discounting rates for delayed sex were higher than those of non-addicted individuals. The particular reason that delay discounting rates for sex are higher than those for money, however, are unclear. Do individuals discount delayed sex rapidly because immediate sex is particularly appealing or because delayed sex does not retain its value? Moreover, do the same factors influence men and women's choices? The current study examined delay discounting in four conditions (money now versus money later; sex now versus sex later; money now, versus sex later; sex now versus money later) in cocaine dependent men and women. The procedures used isolated the role of the immediate versus delayed commodity. For men, the higher rates of delay discounting for sex were because delayed sex did not retain its value, whereas both the immediate and delayed commodity influenced the female participants' decisions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Decomposing the social discount rate

    OpenAIRE

    Scarborough, Helen

    2010-01-01

    Recent modelling of the costs and benefits of climate change has renewed debate surrounding assumptions regarding the social discount rate in analysing the impacts of environmental change. Previous literature segments the social discount rate into being influenced by two key factors; the rate of pure time preference and the elasticity of marginal utility of future consumption. These components of the social discount rate reinforce the linkages between the choice of social discount rate and in...

  11. Cognitive Procedures and Hyperbolic Discounting

    NARCIS (Netherlands)

    Nir, A.

    2004-01-01

    "Hyperbolic discount functions are characterized by a relatively high discount rate over short horizons and a relatively low discount rate over long horizons" (Laibson 1997).We suggest two cognitive procedures where individuals perceive future utility as decreasing at a decreasing rate as a function

  12. Positive autobiographical memory retrieval reduces temporal discounting

    Science.gov (United States)

    Lempert, Karolina M; Speer, Megan E; Delgado, Mauricio R

    2017-01-01

    Abstract People generally prefer rewards sooner rather than later. This phenomenon, temporal discounting, underlies many societal problems, including addiction and obesity. One way to reduce temporal discounting is to imagine positive future experiences. Since there is overlap in the neural circuitry associated with imagining future experiences and remembering past events, here we investigate whether recalling positive memories can also promote more patient choice. We found that participants were more patient after retrieving positive autobiographical memories, but not when they recalled negative memories. Moreover, individuals were more impulsive after imagining novel positive scenes that were not related to their memories, showing that positive imagery alone does not drive this effect. Activity in the striatum and temporo parietal junction during memory retrieval predicted more patient choice, suggesting that to the extent that memory recall is rewarding and involves perspective-taking, it influences decision-making. Furthermore, representational similarity in the ventromedial prefrontal cortex between memory recall and decision phases correlated with the behavioral effect across participants. Thus, we have identified a novel manipulation for reducing temporal discounting—remembering the positive past—and have begun to characterize the psychological and neural mechanisms behind it. PMID:28655195

  13. Shopping in discount stores

    DEFF Research Database (Denmark)

    Zielke, Stephan

    2014-01-01

    quarters of intentions to shop in discount stores. Value perception has the strongest total effect, which is partly mediated by enjoyment, shame and guilt. Attributions influence the shopping intention indirectly via value perception and emotions. The inferior quality attribution has the strongest total......This paper analyzes the impact of price-related attributions, emotions and value perception on the intention to shop at grocery discounters in an integrated framework. Moderating effects of price consciousness are also analyzed. The results show that the proposed model explains almost three...... effect, followed by the efficiency of the business model attribution. The unfairness to stakeholders and the tricks in price communication attribution mostly influence the shopping intention for less price-conscious customers....

  14. Temporal discounting and heart rate reactivity to stress.

    Science.gov (United States)

    Diller, James W; Patros, Connor H G; Prentice, Paula R

    2011-07-01

    Temporal discounting is the reduction of the value of a reinforcer as a function of increasing delay to its presentation. Impulsive individuals discount delayed consequences more rapidly than self-controlled individuals, and impulsivity has been related to substance abuse, gambling, and other problem behaviors. A growing body of literature has identified biological correlates of impulsivity, though little research to date has examined relations between delay discounting and markers of poor health (e.g., cardiovascular reactivity to stress). We evaluated the relation between one aspect of impulsivity, measured using a computerized temporal discounting task, and heart rate reactivity, measured as a change in heart rate from rest during a serial subtraction task. A linear regression showed that individuals who were more reactive to stress responded more impulsively (i.e., discounted delayed reinforcers more rapidly). When results were stratified by gender, the effect was observed for females, but not for males. This finding supports previous research on gender differences in cardiovascular reactivity and suggests that this type of reactivity may be an important correlate of impulsive behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Variable delay-to-signal: a fast paradigm for assessment of aspects of impulsivity in rats

    Directory of Open Access Journals (Sweden)

    Hugo eLeite-Almeida

    2013-10-01

    Full Text Available Testing impulsive behavior in rodents is challenging and labor-intensive. We developed a new behavioral paradigm – the Variable Delay-to-Signal (VDS test – that provides rapid and simultaneous assessment of response and decision impulsivity in rodents. Presentation of a light at variable delays signals the permission for action (nose poke contingent with a reward. Two blocks of 25 trials at 3s delay flank a block of 70 trials in which light is presented with randomly selected 6s or 12s delays. Exposure to such large delays boosts the rate of premature responses when the delay drops to 3s in the final block, an effect that is blunted by an acute methamphetamine challenge and that correlates with the delay-discounting paradigm (choice impulsivity. Finally, as expected, treatment with the NMDA antagonist MK-801 caused a generalized response increase in all VDS blocks. The pharmacological validation, particularly with methamphetamine which has a well established dual effect on response and decision impulsivity, and the correlations between the impulsive behavior in the delay-discounting and VDS paradigms, suggests that the later is able to provide, in a single session, a multi-dimensional assessment of impulsive behavior.

  16. Beyond Rewards

    Science.gov (United States)

    Hall, Philip S.

    2009-01-01

    Using rewards to impact students' behavior has long been common practice. However, using reward systems to enhance student learning conveniently masks the larger and admittedly more difficult task of finding and implementing the structure and techniques that children with special needs require to learn. More important, rewarding the child for good…

  17. Reward positivity: Reward prediction error or salience prediction error?

    Science.gov (United States)

    Heydari, Sepideh; Holroyd, Clay B

    2016-08-01

    The reward positivity is a component of the human ERP elicited by feedback stimuli in trial-and-error learning and guessing tasks. A prominent theory holds that the reward positivity reflects a reward prediction error signal that is sensitive to outcome valence, being larger for unexpected positive events relative to unexpected negative events (Holroyd & Coles, 2002). Although the theory has found substantial empirical support, most of these studies have utilized either monetary or performance feedback to test the hypothesis. However, in apparent contradiction to the theory, a recent study found that unexpected physical punishments also elicit the reward positivity (Talmi, Atkinson, & El-Deredy, 2013). The authors of this report argued that the reward positivity reflects a salience prediction error rather than a reward prediction error. To investigate this finding further, in the present study participants navigated a virtual T maze and received feedback on each trial under two conditions. In a reward condition, the feedback indicated that they would either receive a monetary reward or not and in a punishment condition the feedback indicated that they would receive a small shock or not. We found that the feedback stimuli elicited a typical reward positivity in the reward condition and an apparently delayed reward positivity in the punishment condition. Importantly, this signal was more positive to the stimuli that predicted the omission of a possible punishment relative to stimuli that predicted a forthcoming punishment, which is inconsistent with the salience hypothesis. © 2016 Society for Psychophysiological Research.

  18. Incentive theory: IV. Magnitude of reward

    OpenAIRE

    Killeen, Peter R.

    1985-01-01

    Incentive theory is successfully applied to data from experiments in which the amount of food reward is varied. This is accomplished by assuming that incentive value is a negatively accelerated function of reward duration. The interaction of the magnitude of a reward with its delay is confirmed, and the causes and implications of this interaction are discussed.

  19. Gender-Specific Effects of Cognitive Load on Social Discounting.

    Science.gov (United States)

    Strombach, Tina; Margittai, Zsofia; Gorczyca, Barbara; Kalenscher, Tobias

    2016-01-01

    We live busy, social lives, and meeting the challenges of our complex environments puts strain on our cognitive systems. However, cognitive resources are limited. It is unclear how cognitive load affects social decision making. Previous findings on the effects of cognitive load on other-regarding preferences have been ambiguous, allowing no coherent opinion whether cognitive load increases, decreases or does not affect prosocial considerations. Here, we suggest that social distance between individuals modulates whether generosity towards a recipient increases or decreases under cognitive load conditions. Participants played a financial social discounting task with several recipients at variable social distance levels. In this task, they could choose between generous alternatives, yielding medium financial rewards for the participant and recipient at variable social distances, or between a selfish alternative, yielding larger rewards for the participant alone. We show that the social discount function of male participants was significantly flattened under high cognitive load conditions, suggesting they distinguished less between socially close and socially distant recipients. Unexpectedly, the cognitive-load effect on social discounting was gender-specific: while social discounting was strongly dependent on cognitive load in men, women were nearly unaffected by cognitive load manipulations. We suggest that cognitive load leads men, but not women to simplify the decision problem by neglecting the social distance information. We consider our study a good starting point for further experiments exploring the role of gender in prosocial choice.

  20. Network Effects Versus Strategic Discounting

    DEFF Research Database (Denmark)

    Zucchini, Leon; Claussen, Jörg; Trüg, Moritiz

    . Alternatively, research on strategic discounting suggests small operators use on-net discounts to advertise with low on-net prices. We test the relative strength of these effects using data on tariff setting in German mobile telecommunications between 2001 and 2009. We find that large operators are more likely......Mobile telecommunication operators routinely charge subscribers lower prices for calls on their own network than for calls to other networks (on-net discounts). Studies on tariff-mediated network effects suggest this is due to large operators using on-net discounts to damage smaller rivals...

  1. Beyond the Shadow of a Trait: Understanding Discounting through Item-Level Analysis of Personality Scales

    Science.gov (United States)

    Charlton, Shawn R.; Gossett, Bradley D.; Charlton, Veda A.

    2011-01-01

    Temporal discounting, the loss in perceived value associated with delayed outcomes, correlates with a number of personality measures, suggesting that an item-level analysis of trait measures might provide a more detailed understanding of discounting. The current report details two studies that investigate the utility of such an item-level…

  2. Rewards and Performance Incentives.

    Science.gov (United States)

    Zigon, Jack

    1994-01-01

    Discusses rewards and performance incentives for employees, including types of rewards; how rewards help in managing; dysfunctional awards; selecting the right reward; how to find rewards that fit; and delivering rewards effectively. Examples are included. (three references) (LRW)

  3. 5 CFR 1315.7 - Discounts.

    Science.gov (United States)

    2010-01-01

    ... acceptance has occurred. Agencies are encouraged to include discount terms in a contract to give agencies... web site at http://www.fms.treas.gov/prompt/index.html. (b) Discounts taken after the discount date...

  4. College Students Discount Money "Won" More than Money "Owed"

    Science.gov (United States)

    Weatherly, Jeffrey N.; Derenne, Adam; Terrell, Heather K.

    2010-01-01

    Evidence in the research literature indicates people may treat "won" money differently than they would their own money. The present study had a sample of 648 college students complete a delay-discounting task that involved the hypothetical monetary amounts of $1,000 or $100,000. Participants were asked repeatedly what amount they would…

  5. Towards a healthier discount procedure.

    Science.gov (United States)

    Klock, Rogier M; Brouwer, Werner Bf; Annemans, Lieven Jp; Bos, Jasper M; Postma, Maarten J

    2005-02-01

    Most national guidelines for pharmacoeconomic research prescribe discounting, mostly of money and health against the same rate. There is much debate on whether this is adequate. Two theoretical arguments, the consistency argument of Weinstein and Stason, and the paralyzing paradox of Keeler and Cretin, are mostly responsible for the current standards. However, more recently, several authors have indicated that the basis to claim the necessity of using similar discount rates is rather weak, both practically and theoretically. In terms of finding a new theoretical basis on which to base discount rates for money and, in particular, health, Van Hout has made an important suggestion arguing that the discount rate for health could be based on the expected growth in life expectancy and the diminishing marginal utility related to such additional health. Similarly, Gravelle and Smith argue that if the value of health grows over time, discount rates that are used for costs cannot directly be applied to effects, but should be adjusted downwards.

  6. Estimating Discount Rates

    Directory of Open Access Journals (Sweden)

    Laurence Booth

    2015-04-01

    Full Text Available Discount rates are essential to applied finance, especially in setting prices for regulated utilities and valuing the liabilities of insurance companies and defined benefit pension plans. This paper reviews the basic building blocks for estimating discount rates. It also examines market risk premiums, as well as what constitutes a benchmark fair or required rate of return, in the aftermath of the financial crisis and the U.S. Federal Reserve’s bond-buying program. Some of the results are disconcerting. In Canada, utilities and pension regulators responded to the crash in different ways. Utilities regulators haven’t passed on the full impact of low interest rates, so that consumers face higher prices than they should whereas pension regulators have done the opposite, and forced some contributors to pay more. In both cases this is opposite to the desired effect of monetary policy which is to stimulate aggregate demand. A comprehensive survey of global finance professionals carried out last year provides some clues as to where adjustments are needed. In the U.S., the average equity market required return was estimated at 8.0 per cent; Canada’s is 7.40 per cent, due to the lower market risk premium and the lower risk-free rate. This paper adds a wealth of historic and survey data to conclude that the ideal base long-term interest rate used in risk premium models should be 4.0 per cent, producing an overall expected market return of 9-10.0 per cent. The same data indicate that allowed returns to utilities are currently too high, while the use of current bond yields in solvency valuations of pension plans and life insurers is unhelpful unless there is a realistic expectation that the plans will soon be terminated.

  7. Synchronisation of customers’ orders using discounts

    DEFF Research Database (Denmark)

    Buhayenko, Viktoryia; van Eikenhorst, Erik

    2016-01-01

    Conventionally, price discounts are offered to enhance demand, for example to get rid of excess inventory. This paper, however, studies the possibility of using discounts in situations when total demand is non-sensitive to changes in prices. By introducing a discount in some periods, the supplier...... the supplier's profit a modification of the heuristic which differs in the discount approximation used is developed....

  8. Discounted semi-Markov decision processes : linear programming and policy iteration

    NARCIS (Netherlands)

    Wessels, J.; van Nunen, J.A.E.E.

    1975-01-01

    For semi-Markov decision processes with discounted rewards we derive the well known results regarding the structure of optimal strategies (nonrandomized, stationary Markov strategies) and the standard algorithms (linear programming, policy iteration). Our analysis is completely based on a primal

  9. Discounted semi-Markov decision processes : linear programming and policy iteration

    NARCIS (Netherlands)

    Wessels, J.; van Nunen, J.A.E.E.

    1974-01-01

    For semi-Markov decision processes with discounted rewards we derive the well known results regarding the structure of optimal strategies (nonrandomized, stationary Markov strategies) and the standard algorithms (linear programming, policy iteration). Our analysis is completely based on a primal

  10. Children's Conceptions of Work and Play: Exploring an Alternative to the Discounting Principle.

    Science.gov (United States)

    Hennessey, Beth A.; Berger, Andrea R.

    Factors such as an expected reward have been shown to severely undermine individuals' intrinsic interest in a given task. This "overjustification effect," or "discounting principle," has been demonstrated across the life span, except in the case of young children, who have been shown to be incapable of engaging in this…

  11. Future Discounting by Slum-Dwelling Youth versus University Students in Rio de Janeiro

    Science.gov (United States)

    Ramos, Dandara; Victor, Tania; Seidl-de-Moura, Maria Lucia; Daly, Martin

    2013-01-01

    We compared Future Discounting (FD, preference for smaller, sooner rewards over larger, later ones) by 160 Brazilian youth (16-30 years old; 71 women and 89 men). University students and slum-dwelling (favela) youth were compared. Participants completed a monetary FD task, a scale of youngsters' view of their neighborhood, and self-reported…

  12. I want to media multitask and I want to do it now: Individual differences in media multitasking predict delay of gratification and system-1 thinking.

    Science.gov (United States)

    Schutten, Dan; Stokes, Kirk A; Arnell, Karen M

    2017-01-01

    Media multitasking, the concurrent use of multiple media forms, has been shown to be related to greater self-reported impulsivity and less self-control. These measures are both hallmarks of the need for immediate gratification which has been associated with fast, intuitive 'system-1' decision making, as opposed to more deliberate and effortful 'system-2' decision making. In Study 1, we used the Cognitive Reflection Task (CRT) to examine whether individuals who engage heavily in media multitasking differ from those who are light media multitaskers in their degree of system-1 versus system-2 thinking. In Study 2 we examined whether heavy and light media multitaskers differ in delay of gratification, using the delay discounting measure which estimates the preference for smaller immediate rewards, relative to larger delayed rewards in a hypothetical monetary choice task. We found that heavy media multitaskers were more likely than light media multitaskers to endorse intuitive, but wrong, decisions on the CRT indicating a greater reliance on 'system-1' thinking. Heavy media multitaskers were also willing to settle for less money immediately relative to light media multitaskers who were more willing to wait for the larger delayed reward. These results suggest that heavy media multitaskers have a reactive decision-making style that promotes current desires (money, ease of processing) at the expense of accuracy and future rewards. These findings highlight the potential for heavy media multitaskers to be at risk for problematic behaviors associated with delay discounting - behaviors such as substance abuse, overeating, problematic gambling, and poor financial management.

  13. Deficient neural activity subserving decision-making during reward waiting time in intertemporal choice in adult attention-deficit hyperactivity disorder.

    Science.gov (United States)

    Todokoro, Ayako; Tanaka, Saori C; Kawakubo, Yuki; Yahata, Noriaki; Ishii-Takahashi, Ayaka; Nishimura, Yukika; Kano, Yukiko; Ohtake, Fumio; Kasai, Kiyoto

    2018-04-24

    Impulsivity, which significantly affects social adaptation, is an important target behavioral characteristic in interventions for attention-deficit hyperactivity disorder (ADHD). Typically, people are willing to wait longer to acquire greater rewards. Impulsivity in ADHD may be associated with brain dysfunction in decision-making involving waiting behavior under such situations. We tested the hypothesis that brain circuitry during a period of waiting (i.e., prior to the acquisition of reward) is altered in adults with ADHD. The participants included 14 medication-free adults with ADHD and 16 healthy controls matched for age, sex, IQ, and handedness. The behavioral task had participants choose between a delayed, larger monetary reward and an immediate, smaller monetary reward, where the reward waiting time actually occurred during functional magnetic resonance imaging measurement. We tested for group differences in the contrast values of blood-oxygen-level dependent signals associated with the length of waiting time, calculated using the parametric modulation method. While the two groups did not differ in the time discounting rate, the delay-sensitive contrast values were significantly lower in the caudate and visual cortex in individuals with ADHD. The higher impulsivity scores were significantly associated with lower delay-sensitive contrast values in the caudate and visual cortex. These results suggest that deficient neural activity affects decision-making involving reward waiting time during intertemporal choice tasks, and provide an explanation for the basis of impulsivity in adult ADHD. © 2018 The Author. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

  14. Choice between delayed food and immediate opioids in rats: treatment effects and individual differences.

    Science.gov (United States)

    Panlilio, Leigh V; Secci, Maria E; Schindler, Charles W; Bradberry, Charles W

    2017-11-01

    Addiction involves maladaptive choice behavior in which immediate drug effects are valued more than delayed nondrug rewards. To model this behavior and extend our earlier work with the prescription opioid oxycodone, we allowed rats to choose between immediate intravenous delivery of the short-acting opioid remifentanil and delayed delivery of highly palatable food pellets. Treatment drugs were tested on a baseline where remifentanil was preferred over food. Treatment with a high dose of the opioid antagonist naltrexone decreased but did not reverse the preference for remifentanil. Treatment with the serotonin 5-HT 2C agonist lorcaserin decreased remifentanil and food self-administration nonselectively. Across conditions in which the alternative to delayed food was either a moderate dose of oxycodone, a moderate or high dose of remifentanil, a smaller more immediate delivery of food, or timeout with no primary reinforcement, choice was determined by both the length of the delay and the nature of the alternative option. Delayed food was discounted most steeply when the alternative was a high dose of remifentanil, which was preferred over food when food was delayed by 30 s or more. Within-subject comparisons showed no evidence for trait-like impulsivity or sensitivity to delay across these conditions. Choice was determined more by the current contingencies of reinforcement than by innate individual differences. This finding suggests that people might develop steep delay-discounting functions because of the contingencies in their environment, and it supports the use of contingency management to enhance the relative value of delayed nondrug reinforcers.

  15. The Attraction Effect Modulates Reward Prediction Errors and Intertemporal Choices.

    Science.gov (United States)

    Gluth, Sebastian; Hotaling, Jared M; Rieskamp, Jörg

    2017-01-11

    Classical economic theory contends that the utility of a choice option should be independent of other options. This view is challenged by the attraction effect, in which the relative preference between two options is altered by the addition of a third, asymmetrically dominated option. Here, we leveraged the attraction effect in the context of intertemporal choices to test whether both decisions and reward prediction errors (RPE) in the absence of choice violate the independence of irrelevant alternatives principle. We first demonstrate that intertemporal decision making is prone to the attraction effect in humans. In an independent group of participants, we then investigated how this affects the neural and behavioral valuation of outcomes using a novel intertemporal lottery task and fMRI. Participants' behavioral responses (i.e., satisfaction ratings) were modulated systematically by the attraction effect and this modulation was correlated across participants with the respective change of the RPE signal in the nucleus accumbens. Furthermore, we show that, because exponential and hyperbolic discounting models are unable to account for the attraction effect, recently proposed sequential sampling models might be more appropriate to describe intertemporal choices. Our findings demonstrate for the first time that the attraction effect modulates subjective valuation even in the absence of choice. The findings also challenge the prospect of using neuroscientific methods to measure utility in a context-free manner and have important implications for theories of reinforcement learning and delay discounting. Many theories of value-based decision making assume that people first assess the attractiveness of each option independently of each other and then pick the option with the highest subjective value. The attraction effect, however, shows that adding a new option to a choice set can change the relative value of the existing options, which is a violation of the independence

  16. The effect of natural scenes on temporal and probability discounting

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Results: There was no significant difference in delay discounting between groups F(1,172 = .613, p = .607. Males discounted significantly less than females on temporal and probability discounting tasks F(1,300 = 6.795, p = .010; F(1,300 = 9.941, p = .002, respectively. Older individuals delay discount significantly less than younger individuals F(3,300 = 11.826, p < .001. Older individuals had significantly higher positive affect than younger individuals F(3,300 = 7.956, p < .001. Conclusions: The discounting functions obtained were consistent with previous studies. The results for age and gender on discounting contributes to discussion of these matters: While lower levels of impulsivity in older adults is perhaps to be expected, the gender effect obtained here is less easily explained. Contrary to Berry et al. (2014 we found no evidence for any effect of viewing natural scenes on discounting, regardless of their aesthetic properties. While this discrepancy could relate to the differences in methodology employed, it would suggest that the claims for an effect of natural scenes on impulsivity should be treated with caution.

  17. Intergenerational equity and the social discount rate

    OpenAIRE

    Scarborough, Helen

    2011-01-01

    Recent modelling of the costs and benefits of climate change has renewed debate regarding assumptions for the social discount rate in analysing the impacts of environmental change. Previous literature suggests two key factors influence estimates of the social discount rate: the rate of pure time preference and the elasticity of marginal utility of future consumption. These components of the social discount rate reinforce the linkages between the choice of social discount rate and intergenerat...

  18. Using crowdsourcing to compare temporal, social temporal, and probability discounting among obese and non-obese individuals.

    Science.gov (United States)

    Bickel, Warren K; George Wilson, A; Franck, Christopher T; Terry Mueller, E; Jarmolowicz, David P; Koffarnus, Mikhail N; Fede, Samantha J

    2014-04-01

    Previous research comparing obese and non-obese samples on the delayed discounting procedure has produced mixed results. The aim of the current study was to clarify these discrepant findings by comparing a variety of temporal discounting measures in a large sample of internet users (n=1163) obtained from a crowdsourcing service, Amazon Mechanical Turk (AMT). Measures of temporal, social-temporal (a combination of standard and social temporal), and probability discounting were obtained. Significant differences were obtained on all discounting measures except probability discounting, but the obtained effect sizes were small. These data suggest that larger-N studies will be more likely to detect differences between obese and non-obese samples, and may afford the opportunity, in future studies, to decompose a large obese sample into different subgroups to examine the effect of other relevant measures, such as the reinforcing value of food, on discounting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. 18 CFR 704.39 - Discount rate.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discount rate. 704.39... STANDARDS AND PROCEDURES Standards for Plan Formulation and Evaluation § 704.39 Discount rate. (a) The interest rate to be used in plan formulation and evaluation for discounting future benefits and computing...

  20. Escaping the impulse to immediate gratification: the prospect concept promotes a future-oriented mindset, prompting an inclination towards delayed gratification.

    Science.gov (United States)

    Cheng, Ying-Yao; Shein, Paichi Pat; Chiou, Wen-Bin

    2012-02-01

    People's willingness to postpone receiving an immediate reward in order to gain additional benefits in the future, that is, a tendency to shallow delay discounting, is closely related to one's health, wealth, and happiness. We conducted two experiments investigating how the prospect concept can induce a future-oriented mindset and induce people to behave accordingly. We found that engaging in prospective imagery led the participants to focus on delayed utility over immediate utility in financial decisions (Experiment 1). Participants who received the prospect prime via a scrambled-sentence task decreased their desire to pursue hedonic activities for instant gratification (Experiment 2). Moreover, a state of future orientation mediated the effect of the prospect prime on measures of delayed gratification (Experiments 1 and 2). Thus, reminders of prospect may activate a mindset for future orientation by which delayed gratification is strengthened. ©2011 The British Psychological Society.

  1. A Note on Dynamic Programming with Unbounded Rewards

    NARCIS (Netherlands)

    J.A.E.E. van Nunen (Jo); J. Wessels

    1978-01-01

    textabstractIn a recent paper, Lippman presents sufficient conditions for Denardo's N-stage contraction in discounted semi-Markov decision processes with unbounded rewards. In this note it is demonstrated that Lippman's conditions may be replaced by weaker conditions which even imply l-stage

  2. Intertemporal Decision Making After Brain Injury: Amount-Dependent Steeper Discounting after Frontal Cortex Damage

    Directory of Open Access Journals (Sweden)

    Białaszek Wojciech

    2017-12-01

    Full Text Available Traumatic brain injuries to the frontal lobes are associated with many maladaptive forms of behavior. We investigated the association between brain damage and impulsivity, as measured by the rate of delay discounting (i.e., the extent to which future outcomes are devalued in time. The main aim of this study was to test the hypothesis of steeper discounting of different amounts in a group of patients with frontal lobe damage. We used a delay discounting task in the form of a structured interview. A total of 117 participants were divided into five groups: three neurological groups and two groups without brain damage. Our analyses showed that patients with focal damage to the frontal lobes demonstrated steeper delay discounting than other participants. Other clinical groups demonstrated similar discounting rates. The data pattern related to the magnitude effect on the group level suggested that the magnitude effect is absent in the group of patients with damage to the frontal lobes; however, results were less consistent on an individual level. Amount-dependent discounting was observed in only two groups, the healthy control group and the neurological group with other cortical areas damaged.

  3. Hoarders Only Discount Consumables and are More Patient for Money

    Directory of Open Access Journals (Sweden)

    Brian Donald Vickers

    2016-03-01

    Full Text Available Individuals with hoarding disorder (HD excessively acquire and retain goods while also exhibiting characteristics of impulsivity and addiction. However, HD individuals do not always perform impulsively in experiments, they do not appear interested in money, and they exhibit many features of risk-aversion and future-planning. To examine impulsivity in HD, we compared validated community participants high and low in hoarding tendencies on questionnaire measures of hoarding and impulsivity as well as a standard experimental measure of impulsivity (intertemporal discounting that was modified to compare decisions about money, pens, and snacks. Common discounting effects were replicated. Compared to the low hoarding group, the high hoarding group was more impatient for consumables (pens and snacks but they were more patient for money. This increased patience for money in high hoarding individuals is in contrast to all other studies on discounting in disordered populations, but consistent with the phenomenology of HD. HD does not appear to be driven by a fundamental inability to wait, but rather a specific, potent desire for consumable rewards.

  4. Hoarders Only Discount Consumables and Are More Patient for Money.

    Science.gov (United States)

    Vickers, Brian D; Preston, Stephanie D; Gonzalez, Richard; Angott, Andrea M

    2016-01-01

    Individuals with hoarding disorder (HD) excessively acquire and retain goods while also exhibiting characteristics of impulsivity and addiction. However, HD individuals do not always perform impulsively in experiments, they do not appear interested in money, and they exhibit many features of risk-aversion and future-planning. To examine impulsivity in HD, we compared validated community participants high and low in hoarding tendencies on questionnaire measures of hoarding and impulsivity as well as a standard experimental measure of impulsivity (intertemporal discounting) that was modified to compare decisions about money, pens, and snacks. Common discounting effects were replicated. Compared to the low hoarding group, the high hoarding group was more impatient for consumables (pens and snacks) but they were more patient for money. This increased patience for money in high hoarding individuals is in contrast to all other studies on discounting in disordered populations, but consistent with the phenomenology of HD. HD does not appear to be driven by a fundamental inability to wait, but rather a specific, potent desire for consumable rewards.

  5. Dissociable roles of glucocorticoid and noradrenergic activation on social discounting.

    Science.gov (United States)

    Margittai, Zsofia; van Wingerden, Marijn; Schnitzler, Alfons; Joëls, Marian; Kalenscher, Tobias

    2018-04-01

    People often exhibit prosocial tendencies towards close kin and friends, but generosity decreases as a function of increasing social distance between donor and recipient, a phenomenon called social discounting. Evidence suggests that acute stress affects prosocial behaviour in general and social discounting in particular. We tested the causal role of the important stress neuromodulators cortisol (CORT) and noradrenaline (NA) in this effect by considering two competing hypotheses. On the one hand, it is possible that CORT and NA act in concert to increase generosity towards socially close others by reducing the aversiveness of the cost component in costly altruism and enhancing the emotional salience of vicarious reward. Alternatively, it is equally plausible that CORT and NA exert dissociable, opposing effects on prosocial behaviour based on prior findings implicating CORT in social affiliation, and NA in aggressive and antagonistic tendencies. We pharmacologically manipulated CORT and NA levels in a sample of men (N = 150) and found that isolated hydrocortisone administration promoted prosocial tendencies towards close others, reflected in an altered social discount function, but this effect was offset by concurrent noradrenergic activation brought about by simultaneous yohimbine administration. These results provide inceptive evidence for causal, opposing roles of these two important stress neuromodulators on prosocial behaviour, and give rise to the possibility that, depending on the neuroendocrine response profile, stress neuromodulator action can foster both tend-and-befriend and fight-or-flight tendencies at the same time. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Psychosocial Influences on Fruit and Vegetable Intake Following a NYC Supermarket Discount.

    Science.gov (United States)

    Bernales-Korins, Maria; Ang, Ian Yi Han; Khan, Shamima; Geliebter, Allan

    2017-08-01

    To assess the effect of a 50% discount on fruits and vegetables (F&V) on the purchase and intake of F&V and on psychosocial determinants of F&V intake: self-efficacy (SE), stages of change (SOC), and perceived barriers (PB). This randomized controlled trial was conducted in local supermarkets over 16 weeks, including a 4-week baseline, 8-week discount intervention, and 4-week follow-up. Shoppers with overweight or obesity (BMI > 25) were randomized to receive a discount or no discount via their reward scan card after the baseline. Twenty-four-hour recalls and psychosocial measures were obtained for each study period. Purchases (P supermarket discount intervention led to increases in purchases and intakes of F&V and increases in the psychosocial factors SE and SOC and did not decrease PB. The discount intervention prompted participants to move from the preparation to action stage of SOC, which acted as a mediator for increased F&V intake. © 2017 The Obesity Society.

  7. Major depressive disorder is characterized by greater reward network activation to monetary than pleasant image rewards.

    Science.gov (United States)

    Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S

    2011-12-30

    Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Secretary Problems: Weights and Discounts

    OpenAIRE

    Babaioff, M.; Dinitz, M.; Gupta, A.; Immorlica, Nicole Simone; Talwar, K.

    2009-01-01

    textabstractThe classical secretary problem studies the problem of selecting online an element (a “secretary”) with maximum value in a randomly ordered sequence. The difficulty lies in the fact that an element must be either selected or discarded upon its arrival, and this decision is irrevocable. Constant-competitive algorithms are known for the classical secretary problems and several variants. We study the following two extensions of the secretary problem: In the discounted secretary probl...

  9. Emotional arousal and discount rate in intertemporal choice are reference dependent.

    Science.gov (United States)

    Lempert, Karolina M; Glimcher, Paul W; Phelps, Elizabeth A

    2015-04-01

    Many decisions involve weighing immediate gratification against future consequences. In such intertemporal choices, people often choose smaller, immediate rewards over larger delayed rewards. It has been proposed that emotional responses to immediate rewards lead us to choose them at our long-term expense. Here we utilize an objective measure of emotional arousal-pupil dilation-to examine the role of emotion in these decisions. We show that emotional arousal responses, as well as choices, in intertemporal choice tasks are reference-dependent and reflect the decision-maker's recent history of offers. Arousal increases when less predictable rewards are better than expected, whether those rewards are immediate or delayed. Furthermore, when immediate rewards are less predictable than delayed rewards, participants tend to be patient. When delayed rewards are less predictable, immediate rewards are preferred. Our findings suggest that we can encourage people to be more patient by changing the context in which intertemporal choices are made. (c) 2015 APA, all rights reserved).

  10. It's about time: Earlier rewards increase intrinsic motivation.

    Science.gov (United States)

    Woolley, Kaitlin; Fishbach, Ayelet

    2018-06-01

    Can immediate (vs. delayed) rewards increase intrinsic motivation? Prior research compared the presence versus absence of rewards. By contrast, this research compared immediate versus delayed rewards, predicting that more immediate rewards increase intrinsic motivation by creating a perceptual fusion between the activity and its goal (i.e., the reward). In support of the hypothesis, framing a reward from watching a news program as more immediate (vs. delayed) increased intrinsic motivation to watch the program (Study 1), and receiving more immediate bonus (vs. delayed, Study 2; and vs. delayed and no bonus, Study 3) increased intrinsic motivation in an experimental task. The effect of reward timing was mediated by the strength of the association between an activity and a reward, and was specific to intrinsic (vs. extrinsic) motivation-immediacy influenced the positive experience of an activity, but not perceived outcome importance (Study 4). In addition, the effect of the timing of rewards was independent of the effect of the magnitude of the rewards (Study 5). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  11. Low Discounting Behavior among Small-Scale Fishers in Fiji and Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    Louise S. L. Teh

    2011-06-01

    Full Text Available Understanding the socio-economic factors that are associated with fishers’ willingness to delay gratification may be useful for designing appropriate fisheries management and conservation policies. We aim to identify the predictors of low discounting behaviour among fishers, which is analogous to having a longer-term outlook. We base our empirical study on two small-scale tropical reef fisheries in Sabah, Malaysia, and Fiji. We use an experimental approach to identify fishers with low discount rates, and then use a logistic regression model to identify predictors of low discount rates. We find that 42% of the respondents have low discount rates, and that site and village level variables are significant predictors of low discount rates. Within Sabah and Fiji, boat ownership and relative catch differentiate low discounting from non-low discounting fishers, but these variables have contradictory effects in Sabah and Fiji. Overall, our results imply that a substantial proportion of reef fishers may be willing to engage in conservation initiatives; however, local socio-cultural, economic, and ecological conditions have to be considered first during the process of designing management interventions.

  12. Paralimbic and lateral prefrontal encoding of reward value during intertemporal choice in attempted suicide.

    Science.gov (United States)

    Vanyukov, P M; Szanto, K; Hallquist, M N; Siegle, G J; Reynolds, C F; Forman, S D; Aizenstein, H J; Dombrovski, A Y

    2016-01-01

    Alongside impulsive suicide attempts, clinicians encounter highly premeditated suicidal acts, particularly in older adults. We have previously found that in contrast to the more impulsive suicide attempters' inability to delay gratification, serious and highly planned suicide attempts were associated with greater willingness to wait for larger rewards. This study examined neural underpinnings of intertemporal preference in suicide attempters. We expected that impulsivity and suicide attempts, particularly poorly planned ones, would predict altered paralimbic subjective value representations. We also examined lateral prefrontal and paralimbic correlates of premeditation in suicidal behavior. A total of 48 participants aged 46-90 years underwent extensive clinical and cognitive characterization and completed the delay discounting task in the scanner: 26 individuals with major depression (13 with and 13 without history of suicide attempts) and 22 healthy controls. More impulsive individuals displayed greater activation in the precuneus/posterior cingulate cortex (PCC) to value difference favoring the delayed option. Suicide attempts, particularly better-planned ones, were associated with deactivation of the lateral prefrontal cortex (lPFC) in response to value difference favoring the immediate option. Findings were robust to medication exposure, depression severity and possible brain damage from suicide attempts, among other confounders. Finally, in suicide attempters longer reward delays were associated with diminished parahippocampal responses. Impulsivity was associated with an altered paralimbic (precuneus/PCC) encoding of value difference during intertemporal choice. By contrast, better-planned suicidal acts were associated with altered lPFC representations of value difference. The study provides preliminary evidence of impaired decision processes in both impulsive and premeditated suicidal behavior.

  13. Hyperbolic Discounting of the Far-Distant Future

    OpenAIRE

    Anchugina, Nina; Ryan, Matthew; Slinko, Arkadii

    2017-01-01

    We prove an analogue of Weitzman's (1998) famous result that an exponential discounter who is uncertain of the appropriate exponential discount rate should discount the far-distant future using the lowest (i.e., most patient) of the possible discount rates. Our analogous result applies to a hyperbolic discounter who is uncertain about the appropriate hyperbolic discount rate. In this case, the far-distant future should be discounted using the probability-weighted harmonic mean of the possible...

  14. Reviewing and piloting methods for decreasing discount rates; someone, somewhere in time.

    Science.gov (United States)

    Parouty, Mehraj B Y; Krooshof, Daan G M; Westra, Tjalke A; Pechlivanoglou, Petros; Postma, Maarten J

    2013-08-01

    There has been substantial debate on the need for decreasing discounting for monetary and health gains in economic evaluations. Next to the discussion on differential discounting, a way to identify the need for such discounting strategies is through eliciting the time preferences for monetary and health outcomes. In this article, the authors investigate the perceived time preference for money and health gains through a pilot survey on Dutch university students using methods on functional forms previously suggested. Formal objectives of the study were to review such existing methods and to pilot them on a convenience sample using a questionnaire designed for this specific purpose. Indeed, a negative relation between the time of delay and the variance of the discounting rate for all models was observed. This study was intended as a pilot for a large-scale population-based investigation using the findings from this pilot on wording of the questionnaire, interpretation, scope and analytic framework.

  15. Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward

    Science.gov (United States)

    Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios

    2014-01-01

    To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. PMID:25008408

  16. Motivation and reward systems

    NARCIS (Netherlands)

    van Eerde, W.; Vodosek, M.; den Hartog, D.N.; McNett, J.M.

    2014-01-01

    Reward systems are identified as one of the human resource management (HRM) practices that may impact motivation. Reward systems may consist of several components, including financial and nonfinancial rewards, in fixed and variable amounts. Reinforcement, expectancy, and equity principles are

  17. Life cycle costing with a discount rate

    Science.gov (United States)

    Posner, E. C.

    1978-01-01

    This article studies life cycle costing for a capability needed for the indefinite future, and specifically investigates the dependence of optimal policies on the discount rate chosen. The two costs considered are reprocurement cost and maintenance and operations (M and O) cost. The procurement price is assumed known, and the M and O costs are assumed to be a known function, in fact, a non-decreasing function, of the time since last reprocurement. The problem is to choose the optimum reprocurement time so as to minimize the quotient of the total cost over a reprocurement period divided by the period. Or one could assume a discount rate and try to minimize the total discounted costs into the indefinite future. It is shown that the optimum policy in the presence of a small discount rate hardly depends on the discount rate at all, and leads to essentially the same policy as in the case in which discounting is not considered.

  18. Optimal Discount Rates for Government Projects

    OpenAIRE

    Park, Sangkyun

    2012-01-01

    Project selection based on the net present value can be optimal only if the discount rate is optimal. The optimal discount rate for a government project can be a risk-free rate, a comparable market rate (market interest rate corresponding to the risk of cash flows to the government), or an adjusted market rate, depending on circumstances. This paper clarifies the conditions for each case. Provided that the optimal discount rate is the comparable market rate, it varies across intervention meth...

  19. Essays on Discounting Behavior and Gambling Behavior

    OpenAIRE

    Jessen, Lasse J.

    2016-01-01

    This thesis consists of three independent chapters on the elicitation of individual discount rates and on the estimation of gambling prevalence in Denmark. The first chapter, “Discount Rate Sensitivity to Background Consumption and Consumption Smoothing,” studies the sensitivity of individual discount rates with respect to background consumption and consumption smoothing. I use simulated choice data from standard decision tasks in time preference experiments and show that indiv...

  20. Discounting in economics and climate change

    International Nuclear Information System (INIS)

    Nordhaus, W.D.

    1997-01-01

    This paper examines the complexity of the issues surrounding the discounting issue as applied to the economics of climatic change. It is assumed that living standards will continue to improve, and that future generations will be more able to resource environmental improvements than our own. Measures to counter climate change now may have a deleterious effect on economic growth. Approaches to this situation include: lowering the discount rate; differential discounting; climate targeting; and emissions or concentrations limitations. Policies that focus directly on reducing pollutants are likely to have fewer deleterious economic effects than those that manipulate the discount rate on goods. 3 refs., 2 figs

  1. Social discounting involves modulation of neural value signals by temporoparietal junction

    Science.gov (United States)

    Strombach, Tina; Weber, Bernd; Hangebrauk, Zsofia; Kenning, Peter; Karipidis, Iliana I.; Tobler, Philippe N.; Kalenscher, Tobias

    2015-01-01

    Most people are generous, but not toward everyone alike: generosity usually declines with social distance between individuals, a phenomenon called social discounting. Despite the pervasiveness of social discounting, social distance between actors has been surprisingly neglected in economic theory and neuroscientific research. We used functional magnetic resonance imaging (fMRI) to study the neural basis of this process to understand the neural underpinnings of social decision making. Participants chose between selfish and generous alternatives, yielding either a large reward for the participant alone, or smaller rewards for the participant and another individual at a particular social distance. We found that generous choices engaged the temporoparietal junction (TPJ). In particular, the TPJ activity was scaled to the social-distance–dependent conflict between selfish and generous motives during prosocial choice, consistent with ideas that the TPJ promotes generosity by facilitating overcoming egoism bias. Based on functional coupling data, we propose and provide evidence for a biologically plausible neural model according to which the TPJ supports social discounting by modulating basic neural value signals in the ventromedial prefrontal cortex to incorporate social-distance–dependent other-regarding preferences into an otherwise exclusively own-reward value representation. PMID:25605887

  2. Community-based faculty: motivation and rewards.

    Science.gov (United States)

    Fulkerson, P K; Wang-Cheng, R

    1997-02-01

    The reasons why practicing physicians precept students in their offices, and the rewards they wish to receive for this work, have not been clearly elucidated. This study determined the reasons for precepting and the rewards expected among a network of preceptors in Milwaukee. A questionnaire was mailed to 120 community-based physician preceptors in a required, third-year ambulatory care clerkship. Respondents were asked to identify why they volunteered and what they considered appropriate recognition or reward. The personal satisfaction derived from the student-teacher interaction was, by far, the most important motivator for preceptors (84%). The most preferred rewards for teaching included clinical faculty appointment, CME and bookstore discounts, computer networking, and workshops for improving skills in clinical teaching. Community-based private physicians who participate in medical student education programs are primarily motivated by the personal satisfaction that they derive from the teaching encounter. An effective preceptor recognition/reward program can be developed using input from the preceptors themselves.

  3. Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events.

    Science.gov (United States)

    Murayama, Kou; Kitagami, Shinji

    2014-02-01

    Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward.

  4. Discounting future health benefits: the poverty of consistency arguments.

    Science.gov (United States)

    Nord, Erik

    2011-01-01

    In economic evaluation of health care, main stream practice is to discount benefits at the same rate as costs. But main papers in which this practice is advocated have missed a distinction between two quite different evaluation problems: (1) How much does the time of program occurrence matter for value and (2) how much do delays in health benefits from programs implemented at a given time matter? The papers have furthermore focused on logical and arithmetic arguments rather than on real value considerations. These 'consistency arguments' are at best trivial, at worst logically flawed. At the end of the day, there is a sensible argument for equal discounting of costs and benefits rooted in microeconomic theory of rational, utility maximising consumers' saving behaviour. But even this argument is problematic, first because the model is not clearly supported by empirical observations of individuals' time preferences for health, second because it relates only to evaluation in terms of overall individual utility. It does not provide grounds for claiming that decision makers with a wider societal perspective, which may include concerns for fair distribution, need to discount Copyright © 2010 John Wiley & Sons, Ltd. 2010 John Wiley & Sons, Ltd.

  5. Adaptive neural reward processing during anticipation and receipt of monetary rewards in mindfulness meditators.

    Science.gov (United States)

    Kirk, Ulrich; Brown, Kirk Warren; Downar, Jonathan

    2015-05-01

    Reward seeking is ubiquitous and adaptive in humans. But excessive reward seeking behavior, such as chasing monetary rewards, may lead to diminished subjective well-being. This study examined whether individuals trained in mindfulness meditation show neural evidence of lower susceptibility to monetary rewards. Seventy-eight participants (34 meditators, 44 matched controls) completed the monetary incentive delay task while undergoing functional magnetic resonance imaging. The groups performed equally on the task, but meditators showed lower neural activations in the caudate nucleus during reward anticipation, and elevated bilateral posterior insula activation during reward anticipation. Meditators also evidenced reduced activations in the ventromedial prefrontal cortex during reward receipt compared with controls. Connectivity parameters between the right caudate and bilateral anterior insula were attenuated in meditators during incentive anticipation. In summary, brain regions involved in reward processing-both during reward anticipation and receipt of reward-responded differently in mindfulness meditators than in nonmeditators, indicating that the former are less susceptible to monetary incentives. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  6. Evaluation of Deep Discount Fare Strategies

    Science.gov (United States)

    1995-08-01

    This report evaluates the success of a fare pricing strategy known as deep discounting, that entails the bulk sale of transit tickets or tokens to customers at a significant discount compared to the full fare single ticket price. This market-driven s...

  7. Smoking, Discount Rates, and Returns to Education

    Science.gov (United States)

    Fersterer, Josef; Winter-Ebmer, Rudolf

    2003-01-01

    Individual time preference determines schooling enrolment. Moreover, smoking behavior in early ages has been shown to be highly related to time preference rates. Insofar as discount rates are uncorrelated to ability, predicting school enrolment by discount rates can get rid of the ability bias in an earnings regression. Accordingly, we use smoking…

  8. Essays on Discounting Behavior and Gambling Behavior

    DEFF Research Database (Denmark)

    Jessen, Lasse J.

    This thesis consists of three independent chapters on the elicitation of individual discount rates and on the estimation of gambling prevalence in Denmark. The first chapter, “Discount Rate Sensitivity to Background Consumption and Consumption Smoothing,” studies the sensitivity of individual...

  9. Can Adolescents Learn Self-control? Delay of Gratification in the Development of Control over Risk Taking

    Science.gov (United States)

    Duckworth, Angela L.; Sznitman, Sharon; Park, Sunhee

    2010-01-01

    Recent findings from developmental neuroscience suggest that the adolescent brain is too immature to exert control over impulsive drives, such as sensation seeking, that increase during adolescence. Using a discounting of delayed reward paradigm, this research examines the ability to delay gratification as a potential source of control over risk-taking tendencies that increase during adolescence. In addition, it explores the role of experience resulting from risk taking as well as future time perspective as contributors to the development of this ability. In a nationally representative sample (n=900) of young people aged 14–22, a structural equation analysis shows that risk taking as assessed by use of three popular drugs (tobacco, marijuana, and alcohol) is inversely related to the ability to delay gratification. The relation is robust across gender, age, and different levels of sensation seeking. In addition, high sensation seekers exhibit dramatic age-related increase in delay of gratification, lending support to the hypothesis that engaging in risky behavior provides experience that leads to greater patience for long-term rewards. The findings support the conclusion that a complete understanding of the development of self-control must consider individual differences not easily explained by universal trends in brain maturation. PMID:20306298

  10. Impulsivity in abstinent early- and late-onset alcoholics: differences in self-report measures and a discounting task.

    Science.gov (United States)

    Dom, G; D'haene, P; Hulstijn, W; Sabbe, B

    2006-01-01

    To test the hypothesis that early-onset alcoholics (EOAs) can be differentiated from late-onset alcoholics (LOAs) by more severe substance-related problems and higher levels of impulsivity and aggression. A cross-sectional patient survey with a community comparison group. The European Addiction Severity Index was used to assess substance-related problems and the Barratt Impulsiveness Scale, the Dutch version of the Zuckermann Sensation Seeking Scale and the Buss-Durkee Hostility Inventory were used to assess impulsive and aggressive traits. Impulsive decision making was assessed using a delay discounting task (DDT) with hypothetical monetary rewards. Participants were EOAs (n = 42) and LOAs (n = 46) recruited from an addiction treatment centre and an unmatched, non-substance-abusing comparison group (n = 54). Findings The EOAs had higher levels of impulsive decision making than both the LOAs and the comparison group. The EOAs had higher scores than the LOAs on measures of impulsiveness, aggressiveness and the severity of substance-related problems. This study provides evidence that EOAs are more impulsive and aggressive than LOAs. Further identification of alcoholism subtypes based on dimensions of impulsivity should be considered in the light of their relationship with pharmacological and behavioural treatment interventions.

  11. Focus on the future: Episodic future thinking reduces discount rate and snacking.

    Science.gov (United States)

    Dassen, Fania C M; Jansen, Anita; Nederkoorn, Chantal; Houben, Katrijn

    2016-01-01

    Obesity seems related to a preference for immediate gratification. By changing this focus on short term benefits to a more future-oriented outlook, delay discounting (impulsive decision making) can be changed by a manipulation of episodic future thinking (EFT). EFT comprises a vivid mental simulation of general future experiences. EFT may also affect consumption of unhealthy foods, which can be seen as a choice for immediate gratification. Recent research shows that future orientation should be tailored to the behavior at outcome. We therefore hypothesize that the effectiveness of EFT on food intake could be enhanced by making the content food-related. We conducted a 2 (future vs past thinking) by 2 (food vs non-food related thoughts) between-subject design experiment in female undergraduates (N = 94), to compare the efficacy of EFT versus the recalling of episodic past events in reducing discount rate and caloric intake. Content of imagery was either unrestricted or food-related. Participants engaged in EFT or control episodic imagery while snacks were offered to freely consume, and next the Monetary Choice Questionnaire was completed as a measure of delay discounting, while again being engaged in EFT or control imagery. Both types of EFT reduced delay discounting, however, only food-related EFT lead to more restricted caloric consumption. Thus, we found evidence that EFT reduced discount rate during decision making. However, in order to restrict caloric intake, EFT should entail food-related imagery. As discount rate and caloric intake were not related in the current sample, the underlying mechanism remains to be discovered. Results however suggest that EFT is a promising technique to resist immediate gratification. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Delaying gratification depends on social trust

    Science.gov (United States)

    Michaelson, Laura; de la Vega, Alejandro; Chatham, Christopher H.; Munakata, Yuko

    2013-01-01

    Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then choose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity. PMID:23801977

  13. Delaying gratification depends on social trust

    Directory of Open Access Journals (Sweden)

    Laura eMichaelson

    2013-06-01

    Full Text Available Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then chose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity.

  14. Reward Anticipation in Ventral Striatum and Individual Sensitivity to Reward : A Pilot Study of a Child-Friendly fMRI Task

    NARCIS (Netherlands)

    van Hulst, Branko M; de Zeeuw, Patrick; Lupas, Kellina; Bos, Dienke J; Neggers, Sebastiaan F W; Durston, Sarah

    2015-01-01

    Reward processing has been implicated in developmental disorders. However, the classic task to probe reward anticipation, the monetary incentive delay task, has an abstract coding of reward and no storyline and may therefore be less appropriate for use with developmental populations. We modified the

  15. Discounting Behaviour and the Magnitude Effect

    DEFF Research Database (Denmark)

    Andersen, Steffen; Harrison, Glenn W.; Lau, Morten Igel

    2013-01-01

    We evaluate the claim that individuals exhibit a magnitude effect in their discounting behaviour, where higher discount rates are inferred from choices made with lower principals, all else being equal. If the magnitude effect is quantitatively significant, it is not appropriate to use one discount...... rate that is independent of the scale of the project for cost–benefit analysis and capital budgeting. Using data from a field experiment in Denmark, we find statistically significant evidence of a magnitude effect that is much smaller than is claimed. This evidence surfaces only if one controls...

  16. Dissociable Brain Signatures of Choice Conflict and Immediate Reward Preferences in Alcohol Use Disorders

    Science.gov (United States)

    Amlung, Michael; Sweet, Lawrence H.; Acker, John; Brown, Courtney L.; MacKillop, James

    2013-01-01

    Impulsive delayed reward discounting (DRD) is an important behavioral process in alcohol use disorders (AUDs), reflecting incapacity to delay gratification. Recent work in neuroeconomics has begun to unravel the neural mechanisms supporting DRD, but applications of neuroeconomics in relation to AUDs have been limited. This study examined the neural mechanisms of DRD preferences in AUDs, with emphasis on dissociating activation patterns based on DRD choice type and level of cognitive conflict. Heavy drinking adult males with (n = 13) and without (n = 12) a diagnosis of an AUD completed a monetary DRD task during a functional magnetic resonance imaging scan. Participant responses were coded based on choice type (impulsive vs. restrained) and level of cognitive conflict (easy vs. hard). AUD+ participants exhibited significantly more impulsive DRD decision-making. Significant activation during DRD was found in several decision-making regions, including dorsolateral prefrontal cortex (DLPFC), insula, posterior parietal cortex (PPC), and posterior cingulate. An axis of cognitive conflict was also observed, with hard choices associated with anterior cingulate cortex and easy choices associated with activation in supplementary motor area. AUD+ individuals exhibited significant hyperactivity in regions associated with cognitive control (DLPFC) and prospective thought (PPC) and exhibited less task-related deactivation of areas associated with the brain's default network during DRD decisions. This study provides further clarification of the brain systems supporting DRD in general and in relation to AUDs. PMID:23231650

  17. Dissociable brain signatures of choice conflict and immediate reward preferences in alcohol use disorders.

    Science.gov (United States)

    Amlung, Michael; Sweet, Lawrence H; Acker, John; Brown, Courtney L; MacKillop, James

    2014-07-01

    Impulsive delayed reward discounting (DRD) is an important behavioral process in alcohol use disorders (AUDs), reflecting incapacity to delay gratification. Recent work in neuroeconomics has begun to unravel the neural mechanisms supporting DRD, but applications of neuroeconomics in relation to AUDs have been limited. This study examined the neural mechanisms of DRD preferences in AUDs, with emphasis on dissociating activation patterns based on DRD choice type and level of cognitive conflict. Heavy drinking adult men with (n = 13) and without (n = 12) a diagnosis of an AUD completed a monetary DRD task during a functional magnetic resonance imaging scan. Participant responses were coded based on choice type (impulsive versus restrained) and level of cognitive conflict (easy versus hard). AUD+ participants exhibited significantly more impulsive DRD decision-making. Significant activation during DRD was found in several decision-making regions, including dorsolateral prefrontal cortex (DLPFC), insula, posterior parietal cortex (PPC), and posterior cingulate. An axis of cognitive conflict was also observed, with hard choices associated with anterior cingulate cortex and easy choices associated with activation in supplementary motor area. AUD+ individuals exhibited significant hyperactivity in regions associated with cognitive control (DLPFC) and prospective thought (PPC) and exhibited less task-related deactivation of areas associated with the brain's default network during DRD decisions. This study provides further clarification of the brain systems supporting DRD in general and in relation to AUDs. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.

  18. The Timing Effects of Reward, Business Longevity, and Involvement on Consumers’ Responses to a Reward Program

    Directory of Open Access Journals (Sweden)

    Badri Munir Sukoco

    2015-06-01

    Full Text Available Managers could elicit customers’ repeat purchase behavior through a well-designed reward program. This study examines two extrinsic cues - business longevity and timing effects of reward – to determine the consumers’ perceived risk and intention to participate in this kind of program. Moreover, this study discusses how different levels of involvement might interact with these two cues. An experiment with a 2 (business longevity: long vs. short x 2 (timing of reward: delayed vs. immediate x 2 (involvement: high vs. low between-subject factorial design is conducted to validate the proposed research hypotheses. The results show that an immediate reward offered by an older, more established, firm for a highly-involved product, make loyalty programs less risky and consequently attract consumers to participate. Interestingly, immediate rewards that are offered by older firms for a product that customers are less involved in has the opposite effects. Managerial and academic implications are further presented in this study.

  19. Discounting risks in the far future

    International Nuclear Information System (INIS)

    Lind, Niels

    2007-01-01

    Risks to life and health in the future must be discounted in quantitative risk analysis. Yet, risks in the distant future become trivialized if any reasonable constant interest rate is used. Our responsibility toward future generations rules out such drastic discounting. A solution to this problem is proposed here, resting on the ethical principle that our duty with respect to saving lives is the same to all generations, whether in the near or far future. It is shown that when a choice between prospects involving different risks has a financing horizon T, then ordinary principles of discounting apply up to this time T, while no further discounting is justifiable after T. The principle implies that risk events beyond the financing horizon should be valued as if they occurred at the financing horizon

  20. Time management problems and discounted utility.

    Science.gov (United States)

    König, Cornelius J; Kleinmann, Martin

    2007-05-01

    The lens of behavioral decision theory offers a new perspective for research on time management. The basic idea of this approach is that people discount future consequences of their time management decisions, meaning that they work on tasks with smaller but sooner outcomes rather than on tasks with larger but later outcomes. The authors performed 2 experimental studies to test whether people are sensitive to differences in the discounted utility of time management decisions. In Experiment 1, they used vignettes of typical time management situations; Experiment 2 was a laboratory simulation (an in-basket task that was part of a training assessment). Participants in both studies were German students. As expected, manipulating the discounted utility of options resulted in different time management decisions. In Experiment 1, reactions to time management situations were judged as less likely if the reactions had lower discounted utilities. In Experiment 2, people spent less time on an interruption.

  1. Do Declining Discount Rates lead to Time Inconsistent Economic Advice?

    DEFF Research Database (Denmark)

    Hansen, Anders Chr.

    2006-01-01

    This paper addresses the risk of time inconsistency in economic appraisals related to the use of hyperbolic discounting (declining discount rates) instead of exponential discounting (constant discount rate). Many economists are uneasy about the prospects of potential time inconsistency. The paper...

  2. 7 CFR 1786.153 - Discounted present value.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Discounted present value. 1786.153 Section 1786.153... Discounted Prepayments on RUS Electric Loans § 1786.153 Discounted present value. (a) The discounted present value shall be calculated by summing the present values of all remaining payments on all Qualified Notes...

  3. 7 CFR 1786.53 - Discounted present value.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Discounted present value. 1786.53 Section 1786.53... Special Discounted Prepayments on RUS Direct/Insured Loans § 1786.53 Discounted present value. The Discounted Present Value shall be calculated five business days before prepayment is made by summing the...

  4. Reward-enhanced memory in younger and older adults.

    Science.gov (United States)

    Spaniol, Julia; Schain, Cécile; Bowen, Holly J

    2014-09-01

    We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward-cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase with study-test delay. In Experiment 1, younger and older participants encoded a series of picture stimuli associated with high- or low-reward values. At test (24-hr postencoding), recognition hits resulted in either high or low monetary rewards, whereas false alarms were penalized to discourage guessing. Experiment 2 was similar to Experiment 1, but the study-test delay was manipulated within subjects (immediate vs 24hr). In Experiment 1, younger and older adults showed enhanced recognition for high-reward pictures compared with low-reward pictures. Experiment 2 replicated this finding and additionally showed that the effect did not extend to immediate recognition. The current findings provide support for a time-dependent mechanism of reward-based memory enhancement. They also suggest that aging leaves intact the positive influence of reward anticipation on intentional long-term memory formation. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. TD Waterhouse discount brokerage: a competitive strategy

    OpenAIRE

    Dangerfield, Catherine

    2007-01-01

    This paper provides a strategic analysis of TD Waterhouse (TDW), the discount brokerage provider within TD Bank Financial Group (TDBFG). Discount brokerage in Canada is an increasingly lucrative industry and contributes significantly to the bottom lines of every major financial institution in the country. It is also a rapidly changing and intensely price-competitive industry in which an explicit, educated business strategy is of the utmost importance. TDW currently employs a somewhat ambiguou...

  6. Discounting Models for Outcomes over Continuous Time

    DEFF Research Database (Denmark)

    Harvey, Charles M.; Østerdal, Lars Peter

    Events that occur over a period of time can be described either as sequences of outcomes at discrete times or as functions of outcomes in an interval of time. This paper presents discounting models for events of the latter type. Conditions on preferences are shown to be satisfied if and only if t...... if the preferences are represented by a function that is an integral of a discounting function times a scale defined on outcomes at instants of time....

  7. ACCOUNTING TREATMENT FOR COMMERCIAL DISCOUNTS ON GOODS PURCHASED FOR RESALE

    Directory of Open Access Journals (Sweden)

    HOLT GHEORGHE

    2016-04-01

    Full Text Available In the specialized literature there are two major categories of discounts applied between business partners: trade discounts and financial discounts. In terms of accounting, the method of calculation of interest is commercial and financial cuts, especially the tax treatment of them. Trade discounts are applied prior to financial services, and both types of discounts are calculated on the net earlier. Discounts are calculated after applying discounts and special an issue is to know the level of rebates, which are determined periodically based on the turnover.

  8. Impacts of religious semantic priming on an intertemporal discounting task: Response time effects and neural correlates.

    Science.gov (United States)

    Morgan, Jonathan; Clark, Dustin; Tripodis, Yorghos; Halloran, Christopher S; Minsky, April; Wildman, Wesley J; Durso, Raymon; McNamara, Patrick

    2016-08-01

    The purpose of this study is to test the hypothesis that religious primes would influence intertemporal discounting behaviors in neurotypical older adults, but not in participants with Parkinson's disease (PD). Furthermore, we predicted that this priming effect would be related to functional connectivity within neural networks mediating religious cognition, decision-making, reward valuing, and prospection processes. Contrary to past research with young adults, we found a significant positive relationship between religiosity and discounting rates. Religious semantic primes did not reliably shift individual discounting rates. But religious controls did respond more quickly to intertemporal decisions under the religious priming condition than the neutral condition, compared to response time differences among the participants with PD. Differences in response time were significantly associated with functional connectivity between the nucleus accumbens and various regions, including the left anterior cingulate cortex and Brodmann areas 10 and 46 in the right dorsolateral prefrontal cortex. These results suggest that religious primes influence discounting behavior via dopaminergic meso-limbic and right dorsolateral prefrontal supporting cognitive valuation and prospection processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Reward/Punishment reversal learning in older suicide attempters.

    Science.gov (United States)

    Dombrovski, Alexandre Y; Clark, Luke; Siegle, Greg J; Butters, Meryl A; Ichikawa, Naho; Sahakian, Barbara J; Szanto, Katalin

    2010-06-01

    Suicide rates are high in old age, and the contribution of cognitive risk factors remains poorly understood. Suicide may be viewed as an outcome of an altered decision process. The authors hypothesized that impairment in reward/punishment-based learning, a component of affective decision making, is associated with attempted suicide in late-life depression. They expected that suicide attempters would discount past reward/punishment history, focusing excessively on the most recent rewards and punishments. The authors further hypothesized that this impairment could be dissociated from executive abilities, such as forward planning. The authors assessed reward/punishment-based learning using the probabilistic reversal learning task in 65 individuals age 60 and older: suicide attempters, suicide ideators, nonsuicidal depressed elderly, and nondepressed comparison subjects. The authors used a reinforcement learning computational model to decompose reward/punishment processing over time. The Stockings of Cambridge test served as a control measure of executive function. Suicide attempters but not suicide ideators showed impaired probabilistic reversal learning compared to both nonsuicidal depressed elderly and nondepressed comparison subjects, after controlling for effects of education, global cognitive function, and substance use. Model-based analyses revealed that suicide attempters discounted previous history to a higher degree relative to comparison subjects, basing their choice largely on reward/punishment received on the last trial. Groups did not differ in their performance on the Stockings of Cambridge test. Older suicide attempters display impaired reward/punishment-based learning. The authors propose a hypothesis that older suicide attempters make overly present-focused decisions, ignoring past experiences. Modification of this "myopia for the past" may have therapeutic potential.

  10. Social and monetary reward processing in autism spectrum disorders.

    Science.gov (United States)

    Delmonte, Sonja; Balsters, Joshua H; McGrath, Jane; Fitzgerald, Jacqueline; Brennan, Sean; Fagan, Andrew J; Gallagher, Louise

    2012-09-26

    Social motivation theory suggests that deficits in social reward processing underlie social impairments in autism spectrum disorders (ASD). However, the extent to which abnormalities in reward processing generalize to other classes of stimuli remains unresolved. The aim of the current study was to examine if reward processing abnormalities in ASD are specific to social stimuli or can be generalized to other classes of reward. Additionally, we sought to examine the results in the light of behavioral impairments in ASD. Participants performed adapted versions of the social and monetary incentive delay tasks. Data from 21 unmedicated right-handed male participants with ASD and 21 age- and IQ-matched controls were analyzed using a factorial design to examine the blood-oxygen-level-dependent (BOLD) response during the anticipation and receipt of both reward types. Behaviorally, the ASD group showed less of a reduction in reaction time (RT) for rewarded compared to unrewarded trials than the control group. In terms of the fMRI results, there were no significant group differences in reward circuitry during reward anticipation. During the receipt of rewards, there was a significant interaction between group and reward type in the left dorsal striatum (DS). The ASD group showed reduced activity in the DS compared to controls for social rewards but not monetary rewards and decreased activation for social rewards compared to monetary rewards. Controls showed no significant difference between the two reward types. Increased activation in the DS during social reward processing was associated with faster response times for rewarded trials, compared to unrewarded trials, in both groups. This is in line with behavioral results indicating that the ASD group showed less of a reduction in RT for rewarded compared to unrewarded trials. Additionally, de-activation to social rewards was associated with increased repetitive behavior in ASD. In line with social motivation theory, the ASD

  11. Observed and Normative Discount Functions in Addiction and other Diseases

    OpenAIRE

    Cruz Rambaud, Salvador; Mu?oz Torrecillas, Mar?a J.; Takahashi, Taiki

    2017-01-01

    The aim of this paper is to find a suitable discount function able to describe the progression of a certain addiction or disease under treatment as a discounting process. In effect, a certain indicator related to a disease decays over time in a manner which is mathematically similar to the way in which discounting has been modeled. We analyze the discount functions observed in experiments which study addictive and other problematic behaviors as well as some alternative hyperbola-like discount...

  12. Money Now, Money Later: Linking Time Discounting and Criminal Convictions in the Cambridge Study in Delinquent Development.

    Science.gov (United States)

    Piquero, Alex R; Farrington, David P; Jennings, Wesley G

    2018-04-01

    Two prominent criminological theories offer time discounting, or the preference for an immediate reward over a later one, as a central part of understanding involvement in criminal activity. Yet, there exist only a few studies investigating this issue, and they are limited in a few respects. The current study extends prior work in this area by using multiple measures of time discounting collected at three different periods of the life course to examine the link to criminal offending into late middle adulthood in the Cambridge Study in Delinquent Development. Results show that greater time discounting is positively related to a higher number of criminal convictions by late middle adulthood, and this effect remains after controlling for early life-course individual and environmental risk in a multivariate framework. Study limitations and implications are also discussed.

  13. Reliability of the Discounting Inventory: An extension into substance-use population

    Directory of Open Access Journals (Sweden)

    Malesza Marta

    2017-06-01

    Full Text Available Recent research introduced the Discounting Inventory that allows the measurement of individual differences in the delay, probabilistic, effort, and social discounting rates. The goal of this investigation was to determine several aspects of the reliability of the Discounting Inventory using the responses of 385 participants (200 non-smokers and 185 current-smokers. Two types of reliability are of interest. Internal consistency and test-retest stability. A secondary aim was to extend such reliability measures beyond the non-clinical participant. The current study aimed to measure the reliability of the DI in a nicotine-dependent individuals and non-nicotine-dependent individuals. It is concluded that the internal consistency of the DI is excellent, and that the test-retest reliability results suggest that items intended to measure three types of discounting were likely testing trait, rather than state, factors, regardless of whether “non-smokers” were included in, or excluded from, the analyses (probabilistic discounting scale scores being the exception. With these cautions in mind, however, the psychometric properties of the DI appear to be very good.

  14. Why some people discount more than others: Baseline activation in the dorsal PFC mediates the link between COMT genotype and impatient choice

    Directory of Open Access Journals (Sweden)

    Lorena R. R. Gianotti

    2012-05-01

    Full Text Available Individuals differ widely in how steeply they discount future rewards. The sources of these stable individual differences in delay discounting (DD are largely unknown. One candidate is the COMT Val158Met polymorphism, known to modulate prefrontal dopamine levels and affect DD. To identify possible neural mechanisms by which this polymorphism may contribute to stable individual DD differences, we measured 73 participants’ neural baseline activation using resting electroencephalogram (EEG. Such neural baseline activation measures are highly heritable and stable over time, thus an ideal endophenotype candidate to explain how genes may influence behavior via individual differences in neural function. After EEG-recording, participants made a series of incentive-compatible intertemporal choices to determine the steepness of their DD. We found that COMT significantly affected DD and that this effect was mediated by baseline activation level in the left dorsal prefrontal cortex (DPFC: (i COMT had a significant effect on DD such that the number of Val alleles was positively correlated with steeper DD (higher numbers of Val alleles means greater COMT activity and thus lower dopamine levels. (ii A whole-brain search identified a cluster in left DPFC where baseline activation was correlated with DD; lower activation was associated with steeper DD. (iii COMT had a significant effect on the baseline activation level in this left DPFC cluster such that a higher number of Val alleles was associated with lower baseline activation. (iv The effect of COMT on DD was explained by the mediating effect of neural baseline activation in the left DPFC cluster. Our study thus establishes baseline activation level in left DPFC as salient neural signature in the form of an endophenotype that mediates the link between COMT and DD.

  15. Effects of episodic future thinking on discounting: Personalized age-progressed pictures improve risky long-term health decisions.

    Science.gov (United States)

    Kaplan, Brent A; Reed, Derek D; Jarmolowicz, David P

    2016-03-01

    Many everyday choices are associated with both delayed and probabilistic outcomes. The temporal attention hypothesis suggests that individuals' decision making can be improved by focusing attention on temporally distal events and implies that environmental manipulations that bring temporally distal outcomes into focus may alter an individual's degree of discounting. One such manipulation, episodic future thinking, has shown to lower discount rates; however, several questions remain about the applicability of episodic future thinking to domains other than delay discounting. The present experiments examine the effects of a modified episodic-future-thinking procedure in which participants viewed age-progressed computer-generated images of themselves and answered questions related to their future, on probability discounting in the context of both a delayed health gain and loss. Results indicate that modified episodic future thinking effectively altered individuals' degree of discounting in the predicted directions and demonstrate the applicability of episodic future thinking to decision making of socially significant outcomes. © 2015 Society for the Experimental Analysis of Behavior.

  16. Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward.

    Science.gov (United States)

    Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios; Musallam, Sam

    2014-10-01

    To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. Copyright © 2014 the American Physiological Society.

  17. Heterogeneity of reward mechanisms.

    Science.gov (United States)

    Lajtha, A; Sershen, H

    2010-06-01

    The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.

  18. Dopamine reward prediction error coding

    OpenAIRE

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...

  19. Rewards boost sustained attention through higher effort: A value-based decision making approach.

    Science.gov (United States)

    Massar, Stijn A A; Lim, Julian; Sasmita, Karen; Chee, Michael W L

    2016-10-01

    Maintaining sustained attention over time is an effortful process limited by finite cognitive resources. Recent theories describe the role of motivation in the allocation of such resources as a decision process: the costs of effortful performance are weighed against its gains. We examined this hypothesis by combining methods from attention research and decision neuroscience. Participants first performed a sustained attention task at different levels of reward. They then performed a reward-discounting task, measuring the subjective costs of performance. Results demonstrated that higher rewards led to improved performance (Exp 1-3), and enhanced attentional effort (i.e. pupil diameter; Exp 2 & 3). Moreover, discounting curves constructed from the choice task indicated that subjects devalued rewards that came at the cost of staying vigilant for a longer duration (Exp 1 & 2). Motivation can thus boost sustained attention through increased effort, while sustained performance is regarded as a cost against which rewards are discounted. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. 10% discount at Novae restaurants for students

    CERN Document Server

    2016-01-01

    A 10% discount will be granted for students dining in restaurants 1 and 2 (on the Meyrin site) during the summer from 15 June 2016 to 15 September 2016.   A special badge will be issued by the respective secretariats if the student fulfils the following criteria:  Is under 25 years old; Is in possession of a student card issued by a University or college; Has a CERN contract > 1 month (Users, Summer Students, Trainees, etc). This badge and the CERN access card will have to be shown at the Novae restaurants in order to benefit from this discount.

  1. Episodic Future Thinking about the Ideal Self Induces Lower Discounting, Leading to a Decreased Tendency toward Cheating.

    Science.gov (United States)

    Wu, Wen-Hsiung; Cheng, Wen; Chiou, Wen-Bin

    2017-01-01

    Delay discounting refers to a pervasive tendency toward preferring smaller immediate gains over larger future gains. Recent empirical research has shown that episodic future thinking (EFT; i.e., projecting oneself into the future to pre-experience forthcoming events) can reduce the tendency toward discounting. A common tenet of psychological theories of crime is that delinquency results from focusing on short-term gains while failing to consider adequately the longer-term consequences of delinquent behavior. We investigated whether an EFT intervention involving the ideal self could induce lower discounting rates and, as a consequence, reduced delinquency. The results showed that, compared with control participants, participants engaging in EFT, that is, envisaging life events that would be experienced by their ideal selves, exhibited a lower discounting rate in a monetary choice task (Experiments 1 and 2), as well as a decreased tendency to make delinquent choices in imaginary scenarios (Experiment 1) and cheat in a matrix task (Experiment 2). The discounting tendency mediated the relationship between engaging in EFT pertaining to the ideal self and the tendency toward morally questionable behavior (Experiments 1 and 2). The findings of the two experiments indicate that engagement in EFT with a focus on the ideal self is sufficient to induce lower discounting rates, by promoting consideration of distant costs and thus increasing resistance to delinquent involvement and cheating (given the temptation of the immediate benefits that may accrue from such behavior). The current research constitutes an innovative approach to delinquency prevention and the promotion of morality.

  2. Discounts at the Carlson Wagonlit travel agency

    CERN Document Server

    2008-01-01

    The Carlson Wagonlit travel agency is offering exceptional discounts of up to 40% for bookings with M-Travel before 29 February 2008 and Helvetic Tours before 30 March 2008. For terms and conditions and further information please contact the CERN Carlson Wagonlit Travel office, Main Building (500), Tel. 72763.

  3. Skiba points for small discount rates

    NARCIS (Netherlands)

    Wagener, F.O.O.

    2006-01-01

    The present article uses perturbation techniques to approximate the value function of an economic minimization problem for small values of the discount rate. This can be used to obtain the approximate location of the Skiba states in the problem; these are states for which there are two distinct

  4. Climate policy under sustainable discounted utilitarianism

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Simon [London School of Economics and Political Science (LSE) (United Kingdom); Asheim, Geir B. [Oslo Univ. (Norway). Dept. of Economics

    2011-08-15

    Empirical evaluation of policies to mitigate climate change has been largely confined to the application of discounted utilitarianism (DU). DU is controversial, both due to the conditions through which it is justified and due to its consequences for climate policies, where the discounting of future utility gains from present abatement efforts makes it harder for such measures to justify their present costs. In this paper, we propose sustainable discounted utilitarianism (SDU) as an alternative principle for evaluation of climate policy. Unlike undiscounted utilitarianism, which always assigns zero relative weight to present utility, SDU is an axiomatically based criterion, which departs from DU by assigning zero weight to present utility if and only if the present is better off than the future. Using the DICE integrated assessment model to run risk analysis, we show that it is possible for the future to be worse off than the present along a 'business as usual' development path. Consequently SDU and DU differ, and willingness to pay for emissions reductions is (sometimes significantly) higher under SDU than under DU. Under SDU, stringent schedules of emissions reductions increase social welfare, even for a relatively high utility discount rate. (orig.)

  5. Discounted Markov games : generalized policy iteration method

    NARCIS (Netherlands)

    Wal, van der J.

    1978-01-01

    In this paper, we consider two-person zero-sum discounted Markov games with finite state and action spaces. We show that the Newton-Raphson or policy iteration method as presented by Pollats-chek and Avi-Itzhak does not necessarily converge, contradicting a proof of Rao, Chandrasekaran, and Nair.

  6. Uncertain discount rates in climate policy analysis

    International Nuclear Information System (INIS)

    Newell, R.G.; Pizer, W.A.

    2004-01-01

    Consequences in the distant future - such as those from climate change--have little value today when discounted using conventional rates. This result contradicts our 'gut feeling' about such problems and often leads to ad hoc application of lower rates for valuations over longer horizons - a step facilitated by confusion and disagreement over the correct rate even over short horizons. We review the theory and intuition behind the choice of discount rates now and, importantly, the impact of likely variation in rates in the future. Correlated changes in future rates imply that the distant future should be discounted at much lower rates than suggested by the current rate, thereby raising the value of future consequences - regardless of opinions concerning the current rate. Using historic data to quantity the likely changes and correlation in changes in future rates, we find that future valuations rise by a factor of many thousands at horizons of 300 years or more, almost doubling the expected present value of climate mitigation benefits relative to constant 4% discounting. Ironically, uncertainty about future rates reduces the ratio of valuations based on alternate choices of the current rate

  7. Win-Win Strategies at Discount Stores

    NARCIS (Netherlands)

    B. Deleersnyder (Barbara); M.G. Dekimpe (Marnik); J-B.E.M. Steenkamp (Jan-Benedict); O. Koll (Oliver)

    2005-01-01

    textabstractAn important development that contributes to store brands’ growing success in the grocery market is the increasing number of discount stores that sell predominantly own, private-label, brands. To fight private labels, manufacturers of national brands feel increasingly compelled to

  8. Book Discounts and Cost-Plus Pricing

    Science.gov (United States)

    Andresen, David C.

    1974-01-01

    The adoption of cost-plus pricing by a major book jobber may have profound effects on the discounts that libraries receive. The article explains the pricing system and presents a set of graphs for libraries to use to determine its effects. (Author)

  9. Error Discounting in Probabilistic Category Learning

    Science.gov (United States)

    Craig, Stewart; Lewandowsky, Stephan; Little, Daniel R.

    2011-01-01

    The assumption in some current theories of probabilistic categorization is that people gradually attenuate their learning in response to unavoidable error. However, existing evidence for this error discounting is sparse and open to alternative interpretations. We report 2 probabilistic-categorization experiments in which we investigated error…

  10. Effects of reward and punishment on brain activations associated with inhibitory control in cigarette smokers.

    Science.gov (United States)

    Luijten, Maartje; O'Connor, David A; Rossiter, Sarah; Franken, Ingmar H A; Hester, Robert

    2013-11-01

    Susceptibility to use of addictive substances may result, in part, from a greater preference for an immediate small reward relative to a larger delayed reward or relative insensitivity to punishment. This functional magnetic resonance imaging (fMRI) study examined the neural basis of inhibiting an immediately rewarding stimulus to obtain a larger delayed reward in smokers. We also investigated whether punishment could modulate inhibitory control. The Monetary Incentive Go/NoGo (MI-Go/NoGo) task was administered that provided three types of reward outcomes contingent upon inhibitory control performance over rewarding stimuli: inhibition failure was either followed by no monetary reward (neutral condition), a small monetary reward with immediate feedback (reward condition) or immediate monetary punishment (punishment condition). In the reward and punishment conditions, successful inhibitory control resulted in larger delayed rewards. Community sample of smokers in the Melbourne (Australia) area. Nineteen smokers were compared with 17 demographically matched non-smoking controls. Accuracy, reaction times and brain activation associated with the MI-Go/NoGo task. Smokers showed hyperactivation in the right insula (P rewarding stimulus to obtain a larger delayed reward, and during inhibition of neutral stimuli. Group differences in brain activity were not significant in the punishment condition in the right insula and dorsolateral prefrontal cortex, most probably as a result of increased activation in non-smoking controls. Compared with non-smokers, smokers showed increased neural activation when resisting immediately rewarding stimuli and may be less sensitive to punishment as a strategy to increase control over rewarding stimuli. © 2013 Society for the Study of Addiction.

  11. The role of reward and reward uncertainty in episodic memory

    OpenAIRE

    Mason, Alice; Farrell, Simon; Howard-Jones, Paul; Ludwig, Casimir

    2017-01-01

    Declarative memory has been found to be sensitive to reward-related changes in the environment. The reward signal can be broken down into information regarding the expected value of the reward, reward uncertainty and the prediction error. Research has established that high as opposed to low reward values enhance declarative memory. Research in neuroscience suggests that high uncertainty activates the reward system, which could lead to enhanced learning and memory. Here we present the results ...

  12. Measurement-theoretic foundations of time discounting in economics

    OpenAIRE

    Conrad Heilmann

    2008-01-01

    In economics, the concept of time discounting introduces weights on future goods to make these less valuable. Yet, both the conceptual motivation for time discounting and its specic functional form remain contested. To address these problems, this paper provides a measurement-theoretic framework of representation for time discounting. The representation theorem characterises time discounting factors by representations of time dierences. This general result can be interpreted with existing the...

  13. Effects of acute dopamine precusor depletion on immediate reward selection bias and working memory depend on catechol-O-methyltransferase genotype.

    Science.gov (United States)

    Kelm, Mary Katherine; Boettiger, Charlotte A

    2013-12-01

    Little agreement exists as to acute dopamine (DA) manipulation effects on intertemporal choice in humans. We previously found that catechol-O-methyltransferase (COMT) Val158Met genotype predicts individual differences in immediate reward selection bias among adults. Moreover, we and others have shown that the relationship between COMT genotype and immediate reward bias is inverted in adolescents. No previous pharmacology studies testing DA manipulation effects on intertemporal choice have accounted for COMT genotype, and many have included participants in the adolescent age range (18-21 years) as adults. Moreover, many studies have included female participants without strict cycle phase control, although recent evidence demonstrates that cyclic estradiol elevations interact with COMT genotype to affect DA-dependent cognition. These factors may have interacted with DA manipulations in past studies, potentially occluding detection of effects. Therefore, we predicted that, among healthy male adults (ages 22-40 years), frontal DA tone, as indexed by COMT genotype, would interact with acute changes in DA signaling to affect intertemporal choice. In a double-blind, placebo-controlled design, we decreased central DA via administration of an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine, and tested effects on immediate reward bias in a delay-discounting (DD) task and working memory (WM) in an n-back task. We found no main effect of beverage on DD or WM performance but did find significant beverage*genotype effects. These results suggest that the effect of DA manipulations on DD depends on individual differences in frontal DA tone, which may have impeded some past efforts to characterize DA's role in immediate reward bias in humans.

  14. Reward Merit with Praise.

    Science.gov (United States)

    Andrews, Hans A.

    1987-01-01

    Describes the efforts of two educational institutions to reward teaching excellence using positive feedback rather than merit pay incentives. An Arizona district, drawing on Herzberg's motivation theories, offers highly individualized rewards ranging from computers to conference money, while an Illinois community college bestows engraved plaques…

  15. Dopamine reward prediction error coding.

    Science.gov (United States)

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  16. Destination discount : A sensible road for national brands?

    NARCIS (Netherlands)

    Deleersnyder, B.; Koll, O.

    2012-01-01

    Purpose – This paper aims to study the consequences of listing national brands in discounters. Is the discount channel a promising outlet for manufacturer brands? Is it an effective means to attract new buyers? Which combination of brand and discount destination at which price is best suited for

  17. Discount-Optimal Infinite Runs in Priced Timed Automata

    DEFF Research Database (Denmark)

    Fahrenberg, Uli; Larsen, Kim Guldstrand

    2009-01-01

    We introduce a new discounting semantics for priced timed automata. Discounting provides a way to model optimal-cost problems for infinite traces and has applications in optimal scheduling and other areas. In the discounting semantics, prices decrease exponentially, so that the contribution...

  18. 48 CFR 952.251-70 - Contractor employee travel discounts.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contractor employee travel... Contractor employee travel discounts. As prescribed in 951.7002, insert the following clause: Contractor Employee Travel Discounts (AUG 2009) (a) The Contractor shall take advantage of travel discounts offered to...

  19. 7 CFR 1786.98 - Discounted present value.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Discounted present value. 1786.98 Section 1786.98... Discounted present value. (a) The Discounted Present Value shall be calculated by RUS before prepayment is made by summing the present values of all remaining payments on all outstanding notes according to the...

  20. Discounting medical malpractice claim reserves for self-insured hospitals.

    Science.gov (United States)

    Frese, Richard; Kitchen, Patrick

    2011-01-01

    The hospital CFO often works with the hospital's actuary and external auditor to calculate the reserves recorded in financial statements. Hospital management, usually the CFO, needs to decide the discount rate that is most appropriate. A formal policy addressing the rationale for discounting and the rationale for selecting the discount rate can be helpful to the CFO, actuary, and external auditor.

  1. Probabilistic Discounting of Hypothetical Monetary Gains: University Students Differ in How They Discount "Won" and "Owed" Money

    Science.gov (United States)

    Weatherly, Jeffrey N.; Derenne, Adam

    2013-01-01

    The present study tested whether participants would discount "won" money differently than they would "owed" money in a probability-discounting task. Participants discounted $1000 or $100,000 that they had won in a sweepstakes or that was owed to them using the multiple-choice (Experiment 1) or fill-in-the-blank (Experiment 2) method of collecting…

  2. Pervasive competition between threat and reward in the brain.

    Science.gov (United States)

    Choi, Jong Moon; Padmala, Srikanth; Spechler, Philip; Pessoa, Luiz

    2014-06-01

    In the current functional MRI study, we investigated interactions between reward and threat processing. Visual cues at the start of each trial informed participants about the chance of winning monetary reward and/or receiving a mild aversive shock. We tested two competing hypothesis: according to the 'salience hypothesis', in the condition involving both reward and threat, enhanced activation would be observed because of increased salience; according to the 'competition hypothesis', the processing of reward and threat would trade-off against each other, leading to reduced activation. Analysis of skin conductance data during a delay phase revealed an interaction between reward and threat processing, such that the effect of reward was reduced during threat and the effect of threat was reduced during reward. Analysis of imaging data during the same task phase revealed interactions between reward and threat processing in several regions, including the midbrain/ventral tegmental area, caudate, putamen, bed nucleus of the stria terminalis, anterior insula, middle frontal gyrus and dorsal anterior cingulate cortex. Taken together, our findings reveal conditions during which reward and threat trade-off against each other across multiple sites. Such interactions are suggestive of competitive processes and may reflect the organization of opponent systems in the brain. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  3. Overlapping neural systems represent cognitive effort and reward anticipation.

    Science.gov (United States)

    Vassena, Eliana; Silvetti, Massimo; Boehler, Carsten N; Achten, Eric; Fias, Wim; Verguts, Tom

    2014-01-01

    Anticipating a potential benefit and how difficult it will be to obtain it are valuable skills in a constantly changing environment. In the human brain, the anticipation of reward is encoded by the Anterior Cingulate Cortex (ACC) and Striatum. Naturally, potential rewards have an incentive quality, resulting in a motivational effect improving performance. Recently it has been proposed that an upcoming task requiring effort induces a similar anticipation mechanism as reward, relying on the same cortico-limbic network. However, this overlapping anticipatory activity for reward and effort has only been investigated in a perceptual task. Whether this generalizes to high-level cognitive tasks remains to be investigated. To this end, an fMRI experiment was designed to investigate anticipation of reward and effort in cognitive tasks. A mental arithmetic task was implemented, manipulating effort (difficulty), reward, and delay in reward delivery to control for temporal confounds. The goal was to test for the motivational effect induced by the expectation of bigger reward and higher effort. The results showed that the activation elicited by an upcoming difficult task overlapped with higher reward prospect in the ACC and in the striatum, thus highlighting a pivotal role of this circuit in sustaining motivated behavior.

  4. Individual laboratory-measured discount rates predict field behavior.

    Science.gov (United States)

    Chabris, Christopher F; Laibson, David; Morris, Carrie L; Schuldt, Jonathon P; Taubinsky, Dmitry

    2008-12-01

    We estimate discount rates of 555 subjects using a laboratory task and find that these individual discount rates predict inter-individual variation in field behaviors (e.g., exercise, BMI, smoking). The correlation between the discount rate and each field behavior is small: none exceeds 0.28 and many are near 0. However, the discount rate has at least as much predictive power as any variable in our dataset (e.g., sex, age, education). The correlation between the discount rate and field behavior rises when field behaviors are aggregated: these correlations range from 0.09-0.38. We present a model that explains why specific intertemporal choice behaviors are only weakly correlated with discount rates, even though discount rates robustly predict aggregates of intertemporal decisions.

  5. Model Checking Markov Reward Models with Impulse Rewards

    NARCIS (Netherlands)

    Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong

    This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the

  6. Discount method for programming language evaluation

    DEFF Research Database (Denmark)

    Kurtev, Svetomir; Christensen, Tommy Aagaard; Thomsen, Bent

    2016-01-01

    This paper presents work in progress on developing a Discount Method for Programming Language Evaluation inspired by the Discount Usability Evaluation method (Benyon 2010) and the Instant Data Analysis method (Kjeldskov et al. 2004). The method is intended to bridge the gap between small scale...... internal language design evaluation methods and large scale surveys and quantitative evaluation methods. The method is designed to be applicable even before a compiler or IDE is developed for a new language. To test the method, a usability evaluation experiment was carried out on the Quorum programming...... language (Stefik et al. 2016) using programmers with experience in C and C#. When comparing our results with previous studies of Quorum, most of the data was comparable though not strictly in agreement. However, the discrepancies were mainly related to the programmers pre-existing expectations...

  7. Elevated Striatal Reactivity Across Monetary and Social Rewards in Bipolar I Disorder

    Science.gov (United States)

    Dutra, Sunny J.; Cunningham, William A.; Kober, Hedy; Gruber, June

    2016-01-01

    Bipolar disorder (BD) is associated with increased reactivity to rewards and heightened positive affectivity. It is less clear to what extent this heightened reward sensitivity is evident across contexts and what the associated neural mechanisms might be. The present investigation employed both a monetary and social incentive delay task among adults with remitted BD type I (N=24) and a healthy non-psychiatric control group (HC; N=25) using fMRI. Both whole-brain and region-of-interest analyses revealed elevated ventral and dorsal striatal reactivity across monetary and social reward receipt, but not anticipation, in the BD group. Post-hoc analyses further suggested that greater striatal reactivity to reward receipt across monetary and social reward tasks predicted decreased self-reported positive affect when anticipating subsequent rewards in the HC, but not BD, group. Results point toward elevated striatal reactivity to reward receipt as a potential neural mechanism of reward reactivity. PMID:26390194

  8. Accounting and Tax Issues Concerning Commercial Discounts

    Directory of Open Access Journals (Sweden)

    Sava Raluca

    2015-12-01

    Full Text Available Commercial discounts accounting presents a particular importance because, on the one hand, of their widely spread on a large scale in the commercial activity and on the second hand, due to the influence of the accounting and reporting method over the value added tax. The paper theoretically addresses commercial reductions and also their reflection in the accounting according with the latest regulations in force.

  9. Time discounting and protected-area priorities.

    Science.gov (United States)

    Armsworth, Paul R

    2018-05-08

    Should conservation organizations focus on protecting habitats that are at imminent risk of being converted but are expensive or more remote areas that are less immediately threatened but where a large amount of land can be set aside? Variants of this trade-off commonly arise in spatial planning. We examined this trade-off using models of land use change near a deforestation frontier. The optimal choice of where to protect was determined by how decisions taken today accounted for ecological benefits and economic costs of conservation actions that would occur sometime in the future. We used an ecological and economic discount rate to weight these benefits and costs. A large economic discount rate favored protecting more remote areas, whereas a large, positive ecological discount rate favored protecting habitat near the current deforestation frontier. We also showed how the decision over where to protect was impacted by the influence that economic factors had in determining landowners' decisions, the rate of technological change and ecological heterogeneity of the landscape. How benefits and costs through time are accounted for warrants careful consideration when specifying conservation objectives. It may provide a niche axis along which conservation organizations differentiate themselves when competing for donor funding or other support. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Reward and punishment.

    Science.gov (United States)

    Sigmund, K; Hauert, C; Nowak, M A

    2001-09-11

    Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolution of economically productive behavior, with agents contributing to the public good and either punishing those who do not or rewarding those who do. Reward and punishment correspond to two types of bifurcation with intriguing complementarity. The analysis suggests that reputation is essential for fostering social behavior among selfish agents, and that it is considerably more effective with punishment than with reward.

  11. A Markov reward model checker

    NARCIS (Netherlands)

    Katoen, Joost P.; Maneesh Khattri, M.; Zapreev, I.S.; Zapreev, I.S.

    2005-01-01

    This short tool paper introduces MRMC, a model checker for discrete-time and continuous-time Markov reward models. It supports reward extensions of PCTL and CSL, and allows for the automated verification of properties concerning long-run and instantaneous rewards as well as cumulative rewards. In

  12. Reward, Context, and Human Behaviour

    Directory of Open Access Journals (Sweden)

    Clare L. Blaukopf

    2007-01-01

    Full Text Available Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.

  13. Frontal theta and beta synchronizations for monetary reward increase visual working memory capacity.

    Science.gov (United States)

    Kawasaki, Masahiro; Yamaguchi, Yoko

    2013-06-01

    Visual working memory (VWM) capacity is affected by motivational influences; however, little is known about how reward-related brain activities facilitate the VWM systems. To investigate the dynamic relationship between VWM- and reward-related brain activities, we conducted time-frequency analyses using electroencephalograph (EEG) data obtained during a monetary-incentive delayed-response task that required participants to memorize the position of colored disks. In case of a correct answer, participants received a monetary reward (0, 10 or 50 Japanese yen) announced at the beginning of each trial. Behavioral results showed that VWM capacity under high-reward condition significantly increased compared with that under low- or no-reward condition. EEG results showed that frontal theta (6 Hz) amplitudes enhanced during delay periods and positively correlated with VWM capacity, indicating involvement of theta local synchronizations in VWM. Moreover, frontal beta activities (24 Hz) were identified as reward-related activities, because delay-period amplitudes correlated with increases in VWM capacity between high-reward and no-reward conditions. Interestingly, cross-frequency couplings between frontal theta and beta phases were observed only under high-reward conditions. These findings suggest that the functional dynamic linking between VWM-related theta and reward-related beta activities on the frontal regions plays an integral role in facilitating increases in VWM capacity.

  14. Mixed integer linear programming model for dynamic supplier selection problem considering discounts

    Directory of Open Access Journals (Sweden)

    Adi Wicaksono Purnawan

    2018-01-01

    Full Text Available Supplier selection is one of the most important elements in supply chain management. This function involves evaluation of many factors such as, material costs, transportation costs, quality, delays, supplier capacity, storage capacity and others. Each of these factors varies with time, therefore, supplier identified for one period is not necessarily be same for the next period to supply the same product. So, mixed integer linear programming (MILP was developed to overcome the dynamic supplier selection problem (DSSP. In this paper, a mixed integer linear programming model is built to solve the lot-sizing problem with multiple suppliers, multiple periods, multiple products and quantity discounts. The buyer has to make a decision for some products which will be supplied by some suppliers for some periods cosidering by discount. To validate the MILP model with randomly generated data. The model is solved by Lingo 16.

  15. Observed and Normative Discount Functions in Addiction and other Diseases.

    Science.gov (United States)

    Cruz Rambaud, Salvador; Muñoz Torrecillas, María J; Takahashi, Taiki

    2017-01-01

    The aim of this paper is to find a suitable discount function able to describe the progression of a certain addiction or disease under treatment as a discounting process. In effect, a certain indicator related to a disease decays over time in a manner which is mathematically similar to the way in which discounting has been modeled. We analyze the discount functions observed in experiments which study addictive and other problematic behaviors as well as some alternative hyperbola-like discount functions in order to fit the patience exhibited by the subject after receiving the treatment. Additionally, it has been experimentally found that people with addiction display high rates of discount (impatience) and preference reversals (dynamic inconsistency). This excessive discounting must be correctly modeled by a suitable discount function, otherwise, it can become a trans-disease process underlying addiction and other disorders. The (generalized) exponentiated hyperbolic discount function is proposed to describe the progression of a disease with respect to the treatment, since it maintains the property of inconsistency by exhibiting a decreasing discount rate after an initial period in which the opposite occurs.

  16. Discounting in the economic evaluation of health care interventions.

    Science.gov (United States)

    Krahn, M; Gafni, A

    1993-05-01

    Do economic theories that underlie discounting have specific implications for program evaluation in health? In this study, both the contemporary practice and the theoretical foundations of discounting are reviewed. The social discount rate controversy is considered, and the two major concepts (i.e., opportunity cost and time preference) involved in the formulation of a social discount rate are outlined. Also described are the arguments for discounting proposed by thinkers in non-economic disciplines. Finally, the implications of choosing a discount rate for evaluation of individual health care programs are considered. It is argued that the conventional practice of discounting all health care programs at a rate of 5% may not consistently reflect societal or individual preference. Specific recommendations arising from this paper are: 1) given the considerable disagreement at the theoretical level as to the appropriate social discount rate, analysts should be specific about what theoretical approach underlies their choice of rate, especially when the analytic result is sensitive to the discount rate; 2) the discount rate chosen should be appropriate for the perspective of the analysis (social vs. individual vs. institutional, etc.); 3) when appropriate, measures should be taken to avoid double discounting, because some health related outcome measures already incorporate individuals' time preference; and 4) it is suggested that the political process may serve as the appropriate means of reflecting social values in the choice of a discount rate. In addition, the authors argue that a consensus conference approach, with political participation, offers a flexible, pragmatic, and explicit way of synthesizing the empirical, normative, and ethical considerations that underlie choice of a discount rate.

  17. Cognitive decline is associated with risk aversion and temporal discounting in older adults without dementia.

    Directory of Open Access Journals (Sweden)

    Bryan D James

    Full Text Available Risk aversion and temporal discounting are preferences that are strongly linked to sub-optimal financial and health decision making ability. Prior studies have shown they differ by age and cognitive ability, but it remains unclear whether differences are due to age-related cognitive decline or lower cognitive abilities over the life span. We tested the hypothesis that cognitive decline is associated with higher risk aversion and temporal discounting in 455 older persons without dementia from the Memory and Aging Project, a longitudinal cohort study of aging in Chicago. All underwent repeated annual cognitive evaluations using a detailed battery including 19 tests. Risk aversion was measured using standard behavioral economics questions: participants were asked to choose between a certain monetary payment versus a gamble in which they could gain more or nothing; potential gamble gains varied across questions. Temporal discounting: participants were asked to choose between an immediate, smaller payment and a delayed, larger one; two sets of questions addressed small and large stakes based on payment amount. Regression analyses were used to examine whether prior rate of cognitive decline predicted level of risk aversion and temporal discounting, controlling for age, sex, and education. Over an average of 5.5 (SD=2.9 years, cognition declined at an average of 0.016 units per year (SD=0.03. More rapid cognitive decline predicted higher levels of risk aversion (p=0.002 and temporal discounting (small stakes: p=0.01, high stakes: p=0.006. Further, associations between cognitive decline and risk aversion (p=0.015 and large stakes temporal discounting (p=0.026 persisted in analyses restricted to persons without any cognitive impairment (i.e., no dementia or mild cognitive impairment; the association of cognitive decline and small stakes temporal discounting was no longer statistically significant (p=0.078. These findings are consistent with the

  18. Cognitive decline is associated with risk aversion and temporal discounting in older adults without dementia.

    Science.gov (United States)

    James, Bryan D; Boyle, Patricia A; Yu, Lei; Han, S Duke; Bennett, David A

    2015-01-01

    Risk aversion and temporal discounting are preferences that are strongly linked to sub-optimal financial and health decision making ability. Prior studies have shown they differ by age and cognitive ability, but it remains unclear whether differences are due to age-related cognitive decline or lower cognitive abilities over the life span. We tested the hypothesis that cognitive decline is associated with higher risk aversion and temporal discounting in 455 older persons without dementia from the Memory and Aging Project, a longitudinal cohort study of aging in Chicago. All underwent repeated annual cognitive evaluations using a detailed battery including 19 tests. Risk aversion was measured using standard behavioral economics questions: participants were asked to choose between a certain monetary payment versus a gamble in which they could gain more or nothing; potential gamble gains varied across questions. Temporal discounting: participants were asked to choose between an immediate, smaller payment and a delayed, larger one; two sets of questions addressed small and large stakes based on payment amount. Regression analyses were used to examine whether prior rate of cognitive decline predicted level of risk aversion and temporal discounting, controlling for age, sex, and education. Over an average of 5.5 (SD=2.9) years, cognition declined at an average of 0.016 units per year (SD=0.03). More rapid cognitive decline predicted higher levels of risk aversion (p=0.002) and temporal discounting (small stakes: p=0.01, high stakes: p=0.006). Further, associations between cognitive decline and risk aversion (p=0.015) and large stakes temporal discounting (p=0.026) persisted in analyses restricted to persons without any cognitive impairment (i.e., no dementia or mild cognitive impairment); the association of cognitive decline and small stakes temporal discounting was no longer statistically significant (p=0.078). These findings are consistent with the hypothesis that

  19. Cognitive Control Over Immediate Reward in Binge Alcohol Drinkers.

    Science.gov (United States)

    Poulton, Antoinette; Mackenzie, Caitlyn; Harrington, Kaitlyn; Borg, Sarah; Hester, Robert

    2016-02-01

    Cognitive control deficits, as captured by inhibitory control measures, are indicative of increased impulsivity and are considered a marker for substance use disorder vulnerability. While individuals with alcohol use disorder (AUD) typically exhibit inhibitory control dysfunction, evidence of impaired inhibitory control among harmful drinkers, who are at increased risk of developing an AUD, is mixed. This study examined the response inhibition of binge drinkers using a task that employed neutral, as well as both immediate and delayed reward contingencies, to determine whether reward induced heightened impulsivity in this population. Binge alcohol users (n = 42) and controls (n = 42) were administered a Monetary Incentive Control Task that required participants to successfully inhibit a prepotent motor response to both neutral and immediately rewarding stimuli in order to secure a large delayed reward. Binge drinkers had significantly worse response inhibition than controls irrespective of trial condition and even after controlling for differences in weekly intake. Although both binge and control participants exhibited significantly worse inhibitory control in the presence of immediate reward, the control group showed a greater reduction in inhibition accuracy compared to the binge group in reward relative to neutral conditions. Both groups demonstrated significantly enhanced control when forewarned there was an increased chance response inhibition would be required. Control participants secured the delayed reward more often than binge participants. Despite the variability in the literature, this study demonstrated consistent generalized impulse control deficits among binge-drinking individuals that were unrelated to reward manipulations. These findings point to mechanisms that may confer vulnerability for transition from binge drinking to AUD. Copyright © 2016 by the Research Society on Alcoholism.

  20. The economics of climate change and the theory of discounting

    International Nuclear Information System (INIS)

    Philibert, C.

    1999-01-01

    This paper confronts the theory of discounting with climate change economics. Standard discounting would give long-term damages a very low present value. On the other hand, low discount rates would imply more sacrifices for present generations, although future generations may be richer. And using multiple rates would lead to economic inefficiencies. The paper first shows that arguments favouring a low or zero discount rate in general are weak, even from an ethical point of view. It goes on by considering different arguments in favour of discount rates decreasing over time, and by recalling the argument that non-reproducible environmental assets should be given a value growing over time. Through the example of climate change, it finally shows that the latter argument not only implies that the costs of damages associated to climate change should not be underestimated, but also reinforce the legitimacy of using decreasing discount rates. (author)

  1. Reward Circuitry in Addiction.

    Science.gov (United States)

    Cooper, Sarah; Robison, A J; Mazei-Robison, Michelle S

    2017-07-01

    Understanding the brain circuitry that underlies reward is critical to improve treatment for many common health issues, including obesity, depression, and addiction. Here we focus on insights into the organization and function of reward circuitry and its synaptic and structural adaptations in response to cocaine exposure. While the importance of certain circuits, such as the mesocorticolimbic dopamine pathway, are well established in drug reward, recent studies using genetics-based tools have revealed functional changes throughout the reward circuitry that contribute to different facets of addiction, such as relapse and craving. The ability to observe and manipulate neuronal activity within specific cell types and circuits has led to new insight into not only the basic connections between brain regions, but also the molecular changes within these specific microcircuits, such as neurotrophic factor and GTPase signaling or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, that underlie synaptic and structural plasticity evoked by drugs of abuse. Excitingly, these insights from preclinical rodent work are now being translated into the clinic, where transcranial magnetic simulation and deep brain stimulation therapies are being piloted in human cocaine dependence. Thus, this review seeks to summarize current understanding of the major brain regions implicated in drug-related behaviors and the molecular mechanisms that contribute to altered connectivity between these regions, with the postulation that increased knowledge of the plasticity within the drug reward circuit will lead to new and improved treatments for addiction.

  2. On the Dividend Strategies with Non-Exponential Discounting

    OpenAIRE

    Zhao, Qian; Wei, Jiaqin; Wang, Rongming

    2013-01-01

    In this paper, we study the dividend strategies for a shareholder with non-constant discount rate in a diffusion risk model. We assume that the dividends can only be paid at a bounded rate and restrict ourselves to the Markov strategies. This is a time inconsistent control problem. The extended HJB equation is given and the verification theorem is proved for a general discount function. Considering the pseudo-exponential discount functions (Type I and Type II), we get the equilibrium dividend...

  3. The Individual Health Discount Rate in Patients with Ulcerative Colitis

    Science.gov (United States)

    Waljee, Akbar K.; Morris, Arden M.; Waljee, Jennifer F.; Higgins, Peter D.R.

    2015-01-01

    Background In cost-effectiveness analysis, discount rates are used in calculating the value of future costs and benefits. However, standard discount rates may not accurately describe the decision-making of patients with Ulcerative Colitis (UC). These patients often choose the long-term risks of immunosuppressive therapy over the short-term risks of colectomy, demonstrating very high discount rates for future health. In this study, we aimed to measure the discount rate in UC patients and identify variables associated with the discount rate. Methods We surveyed patients with UC and patients who were post-colectomy for UC to measure their valuations of UC and colectomy health states. We used Standard Gamble(SG) and Time-Trade-Off(TTO) methods to assess current and future health state valuations, and calculated the discount rate. Results Participants included 150 subjects with UC and 150 subjects who were post-colectomy for UC. Discount rates varied widely (20.6%–100%) with an overall median rate of 55.0%, which was significantly higher than the standard rate of 5%. Older age and male gender and predicted high discount rates (aversion to immediate risk in favor of distant future risk). For each additional decade of age, patients’ expected discount rate increased by 0.77%. Female gender was the only predictor of very low discount rates. Female patients’ discount rates averaged 8.1% less than age-matched males. Conclusions The accepted discount rate of 5% grossly underestimates UC patients’ preference for long-term over short-term risk. This might explain UC patients’ frequent choice of the long-term risks of immunosuppressive medical therapy over the short-term risks of colectomy. PMID:21560195

  4. Testable Implications of Quasi-Hyperbolic and Exponential Time Discounting

    OpenAIRE

    Echenique, Federico; Imai, Taisuke; Saito, Kota

    2014-01-01

    We present the first revealed-preference characterizations of the models of exponential time discounting, quasi-hyperbolic time discounting, and other time-separable models of consumers’ intertemporal decisions. The characterizations provide non-parametric revealed-preference tests, which we take to data using the results of a recent experiment conducted by Andreoni and Sprenger (2012). For such data, we find that less than half the subjects are consistent with exponential discounting, and on...

  5. Discounting the future: influence of the economic model.

    Science.gov (United States)

    West, R R

    1996-06-01

    To consider the effect of the economic discount rate on health care policy and the rationale for discounting the collective future of society generally. A review of the concept of discounting the future vis à vis the present from the points of view of individuals (who pass on) and of societies (that continue) and reconsideration of the application of discounting to typical public health scenarios. A public health service, within a basically stable society, which can reasonably anticipate a nearly certain future. Discounting necessarily overvalues the "here and now" compared with the future. While applications of discount rates, typical of those employed in health economic studies in recent years, may seem rational in health care programmes directed at middle aged employed people, they do not for the young and the elderly, important recipients of health care. The consequences of discounting do not accord with the aims and objectives of public health. The "time preferences" of transient individuals within a stable society do not provide a rational basis for time preference of a stable society collectively. Discounting inevitably encourages "short termism" and hence biases public policy decision making. The neoclassical theory that gave rise to the concept of discounting requires revision.

  6. Neurocircuitry of drug reward

    Science.gov (United States)

    Ikemoto, Satoshi; Bonci, Antonello

    2013-01-01

    In recent years, neuroscientists have produced profound conceptual and mechanistic advances on the neurocircuitry of reward and substance use disorders. Here, we will provide a brief review of intracranial drug self-administration and optogenetic self-stimulation studies that identified brain regions and neurotransmitter systems involved in drug- and reward-related behaviors. Also discussed is a theoretical framework that helps to understand the functional properties of the circuitry involved in these behaviors. The circuitry appears to be homeostatically regulated and mediate anticipatory processes that regulate behavioral interaction with the environment in response to salient stimuli. That is, abused drugs or, at least, some may act on basic motivation and mood processes, regulating behavior-environment interaction. Optogenetics and related technologies have begun to uncover detailed circuit mechanisms linking key brain regions in which abused drugs act for rewarding effects. PMID:23664810

  7. The rewarding value of good motor performance in the context of monetary incentives.

    Science.gov (United States)

    Lutz, Kai; Pedroni, Andreas; Nadig, Karin; Luechinger, Roger; Jäncke, Lutz

    2012-07-01

    Whether an agent receives positive task feedback or a monetary reward, neural activity in their striatum increases. In the latter case striatal activity reflects extrinsic reward processing, while in the former, striatal activity reflects the intrinsically rewarding effects of performing well. There can be a "hidden cost of reward", which is a detrimental effect of extrinsic on intrinsic reward value. This raises the question how these two types of reward interact. To address this, we applied a monetary incentive delay task: in all trials participants received feedback depending on their performance. In half of the trials they could additionally receive monetary reward if they performed well. This resulted in high performance trials, which were monetarily rewarded and high performance trials that were not. This made it possible to dissociate the neural correlates of performance feedback from the neural correlates of monetary reward that comes with high performance. Performance feedback alone elicits activation increases in the ventral striatum. This activation increases due to additional monetary reward. Neural response in the dorsal striatum on the other hand is only significantly increased by feedback when a monetary incentive is present. The quality of performance does not significantly influence dorsal striatum activity. In conclusion, our results indicate that the dorsal striatum is primarily sensitive to optional or actually received external rewards, whereas the ventral striatum may be coding intrinsic reward due to positive performance feedback. Thus the ventral striatum is suggested to be involved in the processing of intrinsically motivated behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Event-related EEG responses to anticipation and delivery of monetary and social reward.

    Science.gov (United States)

    Flores, Amanda; Münte, Thomas F; Doñamayor, Nuria

    2015-07-01

    Monetary and a social incentive delay tasks were used to characterize reward anticipation and delivery with electroencephalography. During reward anticipation, N1, P2 and P3 components were modulated by both prospective reward value and incentive type (monetary or social), suggesting distinctive allocation of attentional and motivational resources depending not only on whether rewards or non-rewards were cued, but also on the monetary and social nature of the prospective outcomes. In the delivery phase, P2, FRN and P3 components were also modulated by levels of reward value and incentive type, illustrating how distinctive affective and cognitive processes were attached to the different outcomes. Our findings imply that neural processing of both reward anticipation and delivery can be specific to incentive type, which might have implications for basic as well as translational research. These results are discussed in the light of previous electrophysiological and neuroimaging work using similar tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Intergenerational transfers and the social discount rate

    International Nuclear Information System (INIS)

    Howarth, R.B.; Norgaard, R.B.

    1992-08-01

    This paper investigates the relationship between intergenerational asset transfers and the choice of the discount rate for use in cost-benefit analysis in a model of a competitive overlapping generations economy constrained by a socially managed exhaustible resource. Provided that there are no distortions in capital markets and that all agents hold perfect foresight, cost-benefit techniques will result in a Pareto efficient resource allocation if the discount rate is set equal to the market rate of interest. But since the path of the interest rate depends on the level of intergenerational transfers, cost-benefit techniques do not ensure a socially desirable distribution of welfare between generations; a social optimum will result only if intergenerational transfers are properly chosen and enforced. Decentralized private altruism may result in intergenerational transfers that both present and future individuals would agree are too small if members of the present generation attach positive weight to the general welfare of future generations, not simply their personal descendants. In a world where intergenerational transfers are non-optimal, second-best policy-making may imply a constrained optimum that is inefficient. Together, these findings suggest that cost-benefit analysis is at best a partial criterion to policy formulation that should be used only in conjunction with ethical principles that define the proper distribution of welfare between present and future generations

  10. Reward deficiency and anti-reward in pain chronification

    OpenAIRE

    Borsook, D.; Linnman, C.; Faria, Vanda; Strassman, A. M.; Becerra, L.; Elman, I.

    2016-01-01

    Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between...

  11. Performance analysis of chi models using discrete-time probabilistic reward graphs

    NARCIS (Netherlands)

    Trcka, N.; Georgievska, S.; Markovski, J.; Andova, S.; Vink, de E.P.

    2008-01-01

    We propose the model of discrete-time probabilistic reward graphs (DTPRGs) for performance analysis of systems exhibiting discrete deterministic time delays and probabilistic behavior, via their interpretation as discrete-time Markov reward chains, full-fledged platform for qualitative and

  12. Effects of reward and punishment on brain activations associated with inhibitory control in cigarette smokers

    NARCIS (Netherlands)

    Luijten, M.; O'Connor, D.A.; Rossiter, S.; Franken, I.H.A.; Hester, R.

    2013-01-01

    BACKGROUND AND AIMS: Susceptibility to use of addictive substances may result, in part, from a greater preference for an immediate small reward relative to a larger delayed reward or relative insensitivity to punishment. This functional magnetic resonance imaging (fMRI) study examined the neural

  13. Individual health discount rate in patients with ulcerative colitis.

    Science.gov (United States)

    Waljee, Akbar K; Morris, Arden M; Waljee, Jennifer F; Higgins, Peter D R

    2011-06-01

    In cost-effectiveness analysis, discount rates are used in calculating the value of future costs and benefits. However, standard discount rates may not accurately describe the decision-making of patients with ulcerative colitis (UC). These patients often choose the long-term risks of immunosuppressive therapy over the short-term risks of colectomy, demonstrating very high discount rates for future health. In this study we aimed to measure the discount rate in UC patients and identify variables associated with the discount rate. We surveyed patients with UC and patients who were postcolectomy for UC to measure their valuations of UC and colectomy health states. We used Standard Gamble (SG) and Time-Trade-Off (TTO) methods to assess current and future health state valuations and calculated the discount rate. Participants included 150 subjects with UC and 150 subjects who were postcolectomy for UC. Adjusted discount rates varied widely (0%-100%), with an overall median rate of 55.0% (interquartile range [IQR] 20.6-100), which was significantly higher than the standard rate of 5%. Within the normal range of discount rates, patients' expected discount rate increased by 0.80% for each additional year of age, and female patients had discount rates that averaged ≈ 8% less than their age-matched counterparts and approached statistical significance. The accepted discount rate of 5% grossly underestimates UC patients' preference for long-term over short-term risk. This might explain UC patients' frequent choice of the long-term risks of immunosuppressive medical therapy over the short-term risks of colectomy. Copyright © 2010 Crohn's & Colitis Foundation of America, Inc.

  14. Effects of alexithymia and empathy on the neural processing of social and monetary rewards.

    Science.gov (United States)

    Goerlich, Katharina Sophia; Votinov, Mikhail; Lammertz, Sarah E; Winkler, Lina; Spreckelmeyer, Katja N; Habel, Ute; Gründer, Gerhard; Gossen, Anna

    2017-07-01

    Empathy has been found to affect the neural processing of social and monetary rewards. Alexithymia, a subclinical condition showing a close inverse relationship with empathy is linked to dysfunctions of socio-emotional processing in the brain. Whether alexithymia alters the neural processing of rewards, which is currently unknown. Here, we investigated the influence of both alexithymia and empathy on reward processing using a social incentive delay (SID) task and a monetary incentive delay (MID) task in 45 healthy men undergoing functional magnetic resonance imaging. Controlling for temperament-character dimensions and rejection sensitivity, the relationship of alexithymia and empathy with neural activity in several a priori regions of interest (ROIs) was examined by means of partial correlations, while participants anticipated and received social and monetary rewards. Results were considered significant if they survived Holm-Bonferroni correction for multiple comparisons. Alexithymia modulated neural activity in several ROIs of the emotion and reward network, both during the anticipation of social and monetary rewards and in response to the receipt of monetary rewards. In contrast, empathy did not affect reward anticipation and modulated ROI activity only in response to the receipt of social rewards. These results indicate a significant influence of alexithymia on the processing of social and monetary rewards in the healthy brain.

  15. Stress and reward

    DEFF Research Database (Denmark)

    Chumbley, J R; Hulme, O; Köchli, H

    2014-01-01

    Healthy individuals tend to consume available rewards like food and sex. This tendency is attenuated or amplified in most stress-related psychiatric conditions, so we asked if it depends on endogenous levels of the 'canonical stress hormone' cortisol. We unobtrusively quantified how hard healthy...

  16. Bribes or Rewards.

    Science.gov (United States)

    Megyeri, Kathy A.

    Small tangible rewards for student progress, such as candy bars, pens, or ribbons, add potency to the verbal and written praise offered by the teacher, thus increasing student motivation. Giving students small prizes enhances the cooperative atmosphere of learning, especially for those who do not normally do well. Research indicates that low…

  17. The grateful are patient: Heightened daily gratitude is associated with attenuated temporal discounting.

    Science.gov (United States)

    Dickens, Leah; DeSteno, David

    2016-06-01

    Past research has regularly linked the experience of affect to increased impatience and, thereby, decreased self-control. Given emerging work identifying the emotion gratitude as a fairly unique affective state capable of enhancing, rather than inhibiting, patience, the present study examined the association between chronically elevated gratitude and individual differences in temporal discounting. Participants' levels of gratitude were assessed in response to a standardized lab induction and then over a 3-week period prior to measurement of their financial patience in the form of an incentivized delay discounting task. Analyses revealed a strong relation between lab-based and naturally occurring gratitude levels, thereby confirming the validity of the daily online measures. Of import, mean levels of daily gratitude were significantly associated with increased patience in the form of decreased temporal discounting. As expected, no similar relation emerged for daily levels of happiness, thereby confirming the relative specificity of the positive state of gratitude. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. The relationship between self-control and altruism in the light of discounting literature

    Directory of Open Access Journals (Sweden)

    Osiński Jerzy

    2017-12-01

    Full Text Available On the basis of literature on delay discounting, potential mechanisms of relations between self-control and altruism are considered. The discussed possibilities are: cause-and-effect relationship (self-control enabling sacrificing immediate benefits caused by selfish behaviour in favor of future benefits associated with altruism, e.g. reciprocation, common mechanism (ability to learn behavioural patterns covering longer time periods, role of intelligence as a factor related both to self-control and altruism, and role of psychological distance (the idea of extended self and construal level theory. Relations between described perspectives are pointed out, and directions for further research are suggested.

  19. Changes in reward-induced brain activation in opiate addicts.

    Science.gov (United States)

    Martin-Soelch, C; Chevalley, A F; Künig, G; Missimer, J; Magyar, S; Mino, A; Schultz, W; Leenders, K L

    2001-10-01

    Many studies indicate a role of the cerebral dopaminergic reward system in addiction. Motivated by these findings, we examined in opiate addicts whether brain regions involved in the reward circuitry also react to human prototypical rewards. We measured regional cerebral blood flow (rCBF) with H(2)(15)O positron emission tomography (PET) during a visuo-spatial recognition task with delayed response in control subjects and in opiate addicts participating in a methadone program. Three conditions were defined by the types of feedback: nonsense feedback; nonmonetary reinforcement; or monetary reward, received by the subjects for a correct response. We found in the control subjects rCBF increases in regions associated with the meso-striatal and meso-corticolimbic circuits in response to both monetary reward and nonmonetary reinforcement. In opiate addicts, these regions were activated only in response to monetary reward. Furthermore, nonmonetary reinforcement elicited rCBF increases in limbic regions of the opiate addicts that were not activated in the control subjects. Because psychoactive drugs serve as rewards and directly affect regions of the dopaminergic system like the striatum, we conclude that the differences in rCBF increases between controls and addicts can be attributed to an adaptive consequence of the addiction process.

  20. Zero discounting can compensate future generations for climate damage

    NARCIS (Netherlands)

    Davidson, M.D.

    2014-01-01

    In cost-benefit analysis of climate policy there are two main approaches to discounting, each with implications conflicting with our moral intuitions. Thus, discounted utilitarianism implies that we hardly need to protect future generations against climate change, while classical utilitarianism

  1. Accounting conventions for discounting in the optimisation of protection

    International Nuclear Information System (INIS)

    Fleishman, A.B.

    1983-01-01

    Some of the implications which arise from the use of accounting conventions in the cost benefit framework for optimization of radiation protection are briefly examined. Some accounting techniques which appear not to discount future detriment costs do so, in fact, at a hidden fixed rate; others give a free choice over whether to discount and at what rate. (U.K.)

  2. The Students Decision Making in Solving Discount Problem

    Science.gov (United States)

    Abdillah; Nusantara, Toto; Subanji; Susanto, Hery; Abadyo

    2016-01-01

    This research is reviewing students' process of decision making intuitively, analytically, and interactively. The research done by using discount problem which specially created to explore student's intuition, analytically, and interactively. In solving discount problems, researcher exploring student's decision in determining their attitude which…

  3. Heterogeneity in the Effects of Reward- and Deposit-based Financial Incentives on Smoking Cessation

    Science.gov (United States)

    French, Benjamin; Small, Dylan S.; Saulsgiver, Kathryn; Harhay, Michael O.; Audrain-McGovern, Janet; Loewenstein, George; Asch, David A.; Volpp, Kevin G.

    2016-01-01

    Rationale: Targeting different smoking cessation programs to smokers most likely to quit when using them could reduce the burden of lung disease. Objectives: To identify smokers most likely to quit using pure reward-based financial incentives or incentive programs requiring refundable deposits to become eligible for rewards. Methods: We conducted prespecified secondary analyses of a randomized trial in which 2,538 smokers were assigned to an $800 reward contingent on sustained abstinence from smoking, a refundable $150 deposit plus a $650 reward, or usual care. Measurements and Main Results: Using logistic regression, we identified characteristics of smokers that were most strongly associated with accepting their assigned intervention and ceasing smoking for 6 months. We assessed modification of the acceptance, efficacy, and effectiveness of reward and deposit programs by 11 prospectively selected demographic, smoking-related, and psychological factors. Predictors of sustained smoking abstinence differed among participants assigned to reward- versus deposit-based incentives. However, greater readiness to quit and less steep discounting of future rewards were consistently among the most important predictors. Deposit-based programs were uniquely effective relative to usual care among men, higher-income participants, and participants who more commonly failed to pay their bills (all interaction P values patient characteristics. Clinical trial registered with www.clinicaltrials.gov (NCT 01526265). PMID:27064456

  4. Value of the future: Discounting in random environments

    Science.gov (United States)

    Farmer, J. Doyne; Geanakoplos, John; Masoliver, Jaume; Montero, Miquel; Perelló, Josep

    2015-05-01

    We analyze how to value future costs and benefits when they must be discounted relative to the present. We introduce the subject for the nonspecialist and take into account the randomness of the economic evolution by studying the discount function of three widely used processes for the dynamics of interest rates: Ornstein-Uhlenbeck, Feller, and log-normal. Besides obtaining exact expressions for the discount function and simple asymptotic approximations, we show that historical average interest rates overestimate long-run discount rates and that this effect can be large. In other words, long-run discount rates should be substantially less than the average rate observed in the past, otherwise any cost-benefit calculation would be biased in favor of the present and against interventions that may protect the future.

  5. Exposure to Sexual Stimuli Induces Greater Discounting Leading to Increased Involvement in Cyber Delinquency Among Men.

    Science.gov (United States)

    Cheng, Wen; Chiou, Wen-Bin

    2018-02-01

    People frequently encounter sexual stimuli during Internet use. Research has shown that stimuli inducing sexual motivation can lead to greater impulsivity in men, as manifested in greater temporal discounting (i.e., a tendency to prefer smaller, immediate gains to larger, future ones). Extant findings in crime research suggest that delinquents tend to focus on short-term gains while failing to adequately think through the longer-term consequences of delinquent behavior. We experimentally tested the possibility that exposure to sexual stimuli is associated with the tendency to engage in cyber delinquency among men, as a result of their overly discounting remote consequences. In Experiment 1, participants exposed to pictures of "sexy" women were more likely to discount the future and were more inclined to make cyber-delinquent choices (e.g., cyberbullying, cyber fraud, cyber theft, and illegal downloading), compared with male participants who rated the sex appeal of less sexy opposite-sex pictures. However, these relationships were not observed in female participants exposed to either highly or less sexy pictures of men. In Experiment 2, male participants exposed to sexual primes showed a greater willingness to purchase a wide range of counterfeit rather than authentic products online and experienced a higher likelihood of logging into the other person's Facebook webpage (i.e., invading online privacy). The discounting tendency mediated the link between exposure to sexual primes and the inclination to engage in cyber-delinquent behavior. These findings provide insight into a strategy for reducing men's involvement in cyber delinquency; that is, through less exposure to sexual stimuli and promotion of delayed gratification. The current results suggest that the high availability of sexual stimuli in cyberspace may be more closely associated with men's cyber-delinquent behavior than previously thought.

  6. Delay-Limited Capacity in the Low Power Regime

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    provide a simple characterization of the outage probability in the regime of interest. We quantify the reward due to CSI-TR over the constant-rate constant-power scheme and show that this reward increases with the delay constraint. For instance

  7. WORK COMPETENCES AT WESTERN BANK DISCOUNT

    Directory of Open Access Journals (Sweden)

    Haidee Coste

    2017-03-01

    Full Text Available The research aimed to identify the generic work competences in the staff of the Vice Presidency of Compensation and Development of the Western Bank Discount. Authors were consulted such as Alles (2008, Tobon (2006 and Hay Group (2004, among others. The research is descriptive, non-experimental, transactional and field design. The population consisted of twelve (12 subjects belonging to the vice presidency. It was applied a questionnaire of thirty (30 items, validated by the trial of three (3 experts, with 0.92 reliability by Cronbach alpha coefficient.  It is concluded the employees of the vice presidency have a high level of the generic work competences customer focus, teamwork, effective communication, innovation, emotional intelligence and making decisions. It is strength for the institution, because staff with those competences contributes doing the best for the development of the institution.

  8. Valuing companies by cash flow discounting: Ten methods and nine theories

    OpenAIRE

    Fernández , Pablo

    2002-01-01

    This paper is a summarized compendium of all the methods and theories on company valuation using cash flow discounting. The paper shows the ten most commonly used methods for valuing companies by cash flow discounting: 1) free cash flow discounted at the WACC; 2) equity cash flows discounted at the required return to equity; 3) capital cash flows discounted at the WACC before tax; 4) APV (Adjusted Present Value); 5) the business's risk-adjusted free cash flows discounted at the required retur...

  9. Equivalence of the different discounted cash flow valuation methods. Different alternatives for determining the discounted value of tax shields and their implications for the valuation

    OpenAIRE

    Fernández, Pablo

    1999-01-01

    This paper addresses the valuation of firms by cash flow discounting. The first part shows that the four most commonly used discounted cash flow valuation methods (free cash flow discounted at the WACC; cash flow available for equity holders discounted at the required return on the equity flows; capital cash flow discounted at the WACC before taxes; and Adjusted Present Value) always give the same value. This result is logical because all the methods analyse the same reality under the same hy...

  10. Discounting human lives: Uranium and global equity

    International Nuclear Information System (INIS)

    Goldman, B.A.

    1993-01-01

    Long-term, global environmental health risks complicate efforts to evaluate the efficiency and equity of economic activities from a public welfare perspective. This study sets out a practical framework based on the theory of neoclassical welfare economics for evaluating whether an economic activity yields such inefficient or inequitable net effects to justify government intervention from a variety of decision-making perspectives. It applies this empirical approach to the case of public policies that encouraged uranium production (the mining, milling, and refining of uranium ore) near Elliot Lake and Blind River in Northern Ontario. The analysis tests the two-fold hypothesis that if future negative externalities of production are considered along with past net effects, the these policies result in (1) an inefficient allocation of economic resources according to the potential Pareto criterion, and (2) an inequitable distribution of impacts according to Rawls' maximin criterion. The analytical framework to test these hypotheses has three parts: Risk-cost-benefit analysis, distributions analysis, and efficiency and equity analysis. Quantitative impacts are derived from empirical estimates of cost and benefit streams during 1956 to 1990, and modelled future cancer death costs. Net effects are aggregated to nine observations across three dimensions: Geographic, intergenerational, and social. Qualitative observations are provided about the boom-and-bust uranium economy, environmental burdens, and other unquantifiable impacts. The results illustrate how underlying normative assumptions overwhelm other aspects of efficiency and equity analyses of long-term, global environmental changes. These assumptions appear in discounting equations that ultimately derive from a priori allocations of rights to natural assets and corollary duties to protect such rights. More than two-thirds of the discounting scenarios yield inefficient outcomes and over ninety percent are inequitable

  11. Commitment to Self-Rewards

    OpenAIRE

    Koch, Alexander K.; Nafziger, Julia

    2009-01-01

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of self-denial of the reward after low performance is credible. We explain how a rational forward-looking individual may achieve commitment to self-rewards, by applying Köszegi and Rabin's (2006) model of ...

  12. The amygdala, reward and emotion.

    Science.gov (United States)

    Murray, Elisabeth A

    2007-11-01

    Recent research provides new insights into amygdala contributions to positive emotion and reward. Studies of neuronal activity in the monkey amygdala and of autonomic responses mediated by the monkey amygdala show that, contrary to a widely held view, the amygdala is just as important for processing positive reward and reinforcement as it is for negative. In addition, neuropsychological studies reveal that the amygdala is essential for only a fraction of what might be considered 'stimulus-reward processing', and that the neural substrates for emotion and reward are partially nonoverlapping. Finally, evidence suggests that two systems within the amygdala, operating in parallel, enable reward-predicting cues to influence behavior; one mediates a general, arousing effect of reward and the other links the sensory properties of reward to emotion.

  13. The role of cognitive effort in subjective reward devaluation and risky decision-making.

    Science.gov (United States)

    Apps, Matthew A J; Grima, Laura L; Manohar, Sanjay; Husain, Masud

    2015-11-20

    Motivation is underpinned by cost-benefit valuations where costs-such as physical effort or outcome risk-are subjectively weighed against available rewards. However, in many environments risks pertain not to the variance of outcomes, but to variance in the possible levels of effort required to obtain rewards (effort risks). Moreover, motivation is often guided by the extent to which cognitive-not physical-effort devalues rewards (effort discounting). Yet, very little is known about the mechanisms that underpin the influence of cognitive effort risks or discounting on motivation. We used two cost-benefit decision-making tasks to probe subjective sensitivity to cognitive effort (number of shifts of spatial attention) and to effort risks. Our results show that shifts of spatial attention when monitoring rapidly presented visual stimuli are perceived as effortful and devalue rewards. Additionally, most people are risk-averse, preferring safe, known amounts of effort over risky offers. However, there was no correlation between their effort and risk sensitivity. We show for the first time that people are averse to variance in the possible amount of cognitive effort to be exerted. These results suggest that cognitive effort sensitivity and risk sensitivity are underpinned by distinct psychological and neurobiological mechanisms.

  14. Reward and punishment

    OpenAIRE

    Sigmund, Karl; Hauert, Christoph; Nowak, Martin A.

    2001-01-01

    Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolut...

  15. The effects of reward and punishment on reaction times and autonomic activity in hyperactive and normal children.

    Science.gov (United States)

    Firestone, P; Douglas, V

    1975-01-01

    The performance of hyperactive and control children was compared on a delayed reaction time task under three reinforcement conditions: reward, punishment, and reward plus punishment. Hyperactives had slower and more variable reaction times, suggesting an attentional deficit. Although each of the three reinforcement conditons was successful in improving reaction times for both subject groups, reward led to a significant increase in impulsive responses in the hyperactive children. Autonomic data revealed that reward also increased arousal to a greater extent than punishment or reward plus punishment. Although resting skin conductance was not different in the two groups of subjects, hyperactives produced fewer specific autonomic responses to signal stimuli.

  16. The effects of non-contingent extrinsic and intrinsic rewards on memory consolidation.

    Science.gov (United States)

    Nielson, Kristy A; Bryant, Ted

    2005-07-01

    Emotional and arousing treatments given shortly after learning enhance delayed memory retrieval in animal and human studies. Positive affect and reward induced prior to a variety of cognitive tasks enhance performance, but their ability to affect memory consolidation has not been investigated before. Therefore, we investigated the effects of a small, non-contingent, intrinsic or extrinsic reward on delayed memory retrieval. Participants (n=108) studied and recalled a list of 30 affectively neutral, imageable nouns. Experimental groups were then given either an intrinsic reward (e.g., praise) or an extrinsic reward (e.g., US 1 dollar). After a one-week delay, participants' retrieval performance for the word list was significantly better in the extrinsic reward groups, whether the reward was expected or not, than in controls. Those who received the intrinsic reward performed somewhat better than controls, but the difference was not significant. Thus, at least some forms of arousal and reward, even when semantically unrelated to the learned material, can effectively modulate memory consolidation. These types of treatments might be useful for the development of new memory intervention strategies.

  17. Impulsive social influence increases impulsive choices on a temporal discounting task in young adults.

    Directory of Open Access Journals (Sweden)

    Jodi M Gilman

    Full Text Available Adolescents and young adults who affiliate with friends who engage in impulsive behavior are more likely to engage in impulsive behaviors themselves, and those who associate with prosocial (i.e. more prudent, future oriented peers are more likely to engage in prosocial behavior. However, it is difficult to disentangle the contribution of peer influence vs. peer selection (i.e., whether individuals choose friends with similar traits when interpreting social behaviors. In this study, we combined a novel social manipulation with a well-validated delay discounting task assessing impulsive behavior to create a social influence delay discounting task, in which participants were exposed to both impulsive (smaller, sooner or SS payment and non-impulsive (larger, later or LL payment choices from their peers. Young adults in this sample, n = 51, aged 18-25 had a higher rate of SS choices after exposure to impulsive peer influence than after exposure to non-impulsive peer influence. Interestingly, in highly susceptible individuals, the rate of non-impulsive choices did not increase after exposure to non-impulsive influence. There was a positive correlation between self-reported suggestibility and degree of peer influence on SS choices. These results suggest that, in young adults, SS choices appear to be influenced by the choices of same-aged peers, especially for individuals who are highly susceptible to influence.

  18. Impulsive Social Influence Increases Impulsive Choices on a Temporal Discounting Task in Young Adults

    Science.gov (United States)

    Gilman, Jodi M.; Curran, Max T.; Calderon, Vanessa; Stoeckel, Luke E.; Evins, A. Eden

    2014-01-01

    Adolescents and young adults who affiliate with friends who engage in impulsive behavior are more likely to engage in impulsive behaviors themselves, and those who associate with prosocial (i.e. more prudent, future oriented) peers are more likely to engage in prosocial behavior. However, it is difficult to disentangle the contribution of peer influence vs. peer selection (i.e., whether individuals choose friends with similar traits) when interpreting social behaviors. In this study, we combined a novel social manipulation with a well-validated delay discounting task assessing impulsive behavior to create a social influence delay discounting task, in which participants were exposed to both impulsive (smaller, sooner or SS payment) and non-impulsive (larger, later or LL payment) choices from their peers. Young adults in this sample, n = 51, aged 18–25 had a higher rate of SS choices after exposure to impulsive peer influence than after exposure to non-impulsive peer influence. Interestingly, in highly susceptible individuals, the rate of non-impulsive choices did not increase after exposure to non-impulsive influence. There was a positive correlation between self-reported suggestibility and degree of peer influence on SS choices. These results suggest that, in young adults, SS choices appear to be influenced by the choices of same-aged peers, especially for individuals who are highly susceptible to influence. PMID:24988440

  19. Incomplete information and the closed-end fund discount

    OpenAIRE

    Barone-Adesi, Giovanni; Kim, Youngsoo

    2008-01-01

    We model the closed-end fund discount/premium in a version of Merton’s (1978) asset pricing model with incomplete information. In this economy, investors trade only assets which they “ know about” . The model generates a closed-end fund discount or premium, depending on risk-aversion parameters. The fund share price reverts to the net asset value on open-ending of the fund. The discount/premium is a result of two economic forces: (1) the fund manager’s objective is to maximize expected utilit...

  20. Where do we stand on discounts? - A Danish perspective

    DEFF Research Database (Denmark)

    Bergqvist, Christian

    The dominant undertaking’s ability to award discounts and other loyalty inducing considerations are subject to much ambiguity and many unsettled issues. Despite discounts being a commercial requirement, even for the dominant undertaking, it’s difficult to draw up clear principles, and while...... the approach to non-dominant undertaking’s restriction of competition has been fundamentally recast over the last 20 years, the appraisal of single company behaviour remains more formal and rigid. However, there have recently been indications that some of the same leniency might have been extended to discounts...

  1. Discounted cost model for condition-based maintenance optimization

    International Nuclear Information System (INIS)

    Weide, J.A.M. van der; Pandey, M.D.; Noortwijk, J.M. van

    2010-01-01

    This paper presents methods to evaluate the reliability and optimize the maintenance of engineering systems that are damaged by shocks or transients arriving randomly in time and overall degradation is modeled as a cumulative stochastic point process. The paper presents a conceptually clear and comprehensive derivation of formulas for computing the discounted cost associated with a maintenance policy combining both condition-based and age-based criteria for preventive maintenance. The proposed discounted cost model provides a more realistic basis for optimizing the maintenance policies than those based on the asymptotic, non-discounted cost rate criterion.

  2. Where Do We Stand on Discounts? - A Nordic Perspective

    DEFF Research Database (Denmark)

    Bastida, Vladimir; Ballebye Okholm, Henrik; Pedersen, Torben

    Dominant undertakings’ ability, under competition law, to award discounts and other loyalty inducing considerations are subject to much ambiguity and unsettled issues. Despite discounts being a commercial requirement, even for the dominant undertaking, it is difficult to draw up clear principles....... to dis-counts and unilateral behaviour and in particular the 2017 Court of Justice rul-ing in Intel has reopened the discussions. The objective of this book is to pro-vide guidance on the matter under EU and Nordic competition law and to align these with economic theory....

  3. Led into temptation? Rewarding brand logos bias the neural encoding of incidental economic decisions.

    Directory of Open Access Journals (Sweden)

    Carsten Murawski

    Full Text Available Human decision-making is driven by subjective values assigned to alternative choice options. These valuations are based on reward cues. It is unknown, however, whether complex reward cues, such as brand logos, may bias the neural encoding of subjective value in unrelated decisions. In this functional magnetic resonance imaging (fMRI study, we subliminally presented brand logos preceding intertemporal choices. We demonstrated that priming biased participants' preferences towards more immediate rewards in the subsequent temporal discounting task. This was associated with modulations of the neural encoding of subjective values of choice options in a network of brain regions, including but not restricted to medial prefrontal cortex. Our findings demonstrate the general susceptibility of the human decision making system to apparently incidental contextual information. We conclude that the brain incorporates seemingly unrelated value information that modifies decision making outside the decision-maker's awareness.

  4. Led into temptation? Rewarding brand logos bias the neural encoding of incidental economic decisions.

    Science.gov (United States)

    Murawski, Carsten; Harris, Philip G; Bode, Stefan; Domínguez D, Juan F; Egan, Gary F

    2012-01-01

    Human decision-making is driven by subjective values assigned to alternative choice options. These valuations are based on reward cues. It is unknown, however, whether complex reward cues, such as brand logos, may bias the neural encoding of subjective value in unrelated decisions. In this functional magnetic resonance imaging (fMRI) study, we subliminally presented brand logos preceding intertemporal choices. We demonstrated that priming biased participants' preferences towards more immediate rewards in the subsequent temporal discounting task. This was associated with modulations of the neural encoding of subjective values of choice options in a network of brain regions, including but not restricted to medial prefrontal cortex. Our findings demonstrate the general susceptibility of the human decision making system to apparently incidental contextual information. We conclude that the brain incorporates seemingly unrelated value information that modifies decision making outside the decision-maker's awareness.

  5. Modulation of risk/reward decision making by dopaminergic transmission within the basolateral amygdala.

    Science.gov (United States)

    Larkin, Joshua D; Jenni, Nicole L; Floresco, Stan B

    2016-01-01

    Dopamine (DA) transmission within cortico-limbic-striatal circuitry is integral in modulating decisions involving reward uncertainty. The basolateral amygdala (BLA) also plays a role in these processes, yet how DA transmission within this nucleus regulates cost/benefit decision making is unknown. We investigated the contribution of DA transmission within the BLA to risk/reward decision making assessed with a probabilistic discounting task. Rats were well-trained to choose between a small/certain reward and a large/risky reward, with the probability of obtaining the larger reward decreasing (100-12.5 %) or increasing (12.5-100 %) over a session. We examined the effects of antagonizing BLA D1 (SCH 23390, 0.1-1 μg) or D2 (eticlopride, 0.1-1 μg) receptors, as well as intra-BLA infusions of agonists for D1 (SKF 81297, 0.1-1 μg) and D2 (quinpirole, 1-10 μg) receptors. We also assessed how DA receptor stimulation may induce differential effects related to baseline levels of risky choice. BLA D1 receptor antagonism reduced risky choice by decreasing reward sensitivity, whereas D2 antagonism did not affect overall choice patterns. Stimulation of BLA D1 receptors optimized decision making in a baseline-dependent manner: in risk-averse rats, infusions of a lower dose of SKF81297 increased risky choice when reward probabilities were high (50 %), whereas in risk-prone rats, this drug reduced risky choice when probabilities were low (12.5 %). Quinpirole reduced risky choice in risk-prone rats, enhancing lose-shift behavior. These data highlight previously uncharacterized roles for BLA DA D1 and D2 receptors in biasing choice during risk/reward decision making through mediation of reward/negative feedback sensitivity.

  6. Heterogeneity in the Effects of Reward- and Deposit-based Financial Incentives on Smoking Cessation.

    Science.gov (United States)

    Halpern, Scott D; French, Benjamin; Small, Dylan S; Saulsgiver, Kathryn; Harhay, Michael O; Audrain-McGovern, Janet; Loewenstein, George; Asch, David A; Volpp, Kevin G

    2016-10-15

    Targeting different smoking cessation programs to smokers most likely to quit when using them could reduce the burden of lung disease. To identify smokers most likely to quit using pure reward-based financial incentives or incentive programs requiring refundable deposits to become eligible for rewards. We conducted prespecified secondary analyses of a randomized trial in which 2,538 smokers were assigned to an $800 reward contingent on sustained abstinence from smoking, a refundable $150 deposit plus a $650 reward, or usual care. Using logistic regression, we identified characteristics of smokers that were most strongly associated with accepting their assigned intervention and ceasing smoking for 6 months. We assessed modification of the acceptance, efficacy, and effectiveness of reward and deposit programs by 11 prospectively selected demographic, smoking-related, and psychological factors. Predictors of sustained smoking abstinence differed among participants assigned to reward- versus deposit-based incentives. However, greater readiness to quit and less steep discounting of future rewards were consistently among the most important predictors. Deposit-based programs were uniquely effective relative to usual care among men, higher-income participants, and participants who more commonly failed to pay their bills (all interaction P values rewards, deposits were more effective among black persons (P = 0.022) and those who more commonly failed to pay their bills (P = 0.082). Relative to rewards, deposits were more commonly accepted by higher-income participants, men, white persons, and those who less commonly failed to pay their bills (all P incentives suggests potential benefits of targeting behavior-change interventions based on patient characteristics. Clinical trial registered with www.clinicaltrials.gov (NCT 01526265).

  7. Social reward shapes attentional biases.

    Science.gov (United States)

    Anderson, Brian A

    2016-01-01

    Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us.

  8. Reward Anticipation in Ventral Striatum and Individual Sensitivity to Reward: A Pilot Study of a Child-Friendly fMRI Task.

    Science.gov (United States)

    van Hulst, Branko M; de Zeeuw, Patrick; Lupas, Kellina; Bos, Dienke J; Neggers, Sebastiaan F W; Durston, Sarah

    2015-01-01

    Reward processing has been implicated in developmental disorders. However, the classic task to probe reward anticipation, the monetary incentive delay task, has an abstract coding of reward and no storyline and may therefore be less appropriate for use with developmental populations. We modified the task to create a version appropriate for use with children. We investigated whether this child-friendly version could elicit ventral striatal activation during reward anticipation in typically developing children and young adolescents (aged 9.5-14.5). In addition, we tested whether our performance-based measure of reward sensitivity was associated with anticipatory activity in ventral striatum. Reward anticipation was related to activity in bilateral ventral striatum. Moreover, we found an association between individual reward sensitivity and activity in ventral striatum. We conclude that this task assesses ventral striatal activity in a child-friendly paradigm. The combination with a performance-based measure of reward sensitivity potentially makes the task a powerful tool for developmental imaging studies of reward processing.

  9. Discounting the distant future—Data on Australian discount rates estimated by a stochastic interest rate model

    Directory of Open Access Journals (Sweden)

    Chi Truong

    2017-04-01

    Full Text Available Data on certainty equivalent discount factors and discount rates for stochastic interest rates in Australia are provided in this paper. The data has been used for the analysis of investments into climate adaptation projects in ׳It׳s not now or never: Implications of investment timing and risk aversion on climate adaptation to extreme events׳ (Truong and Trück, 2016 [3] and can be used for other cost-benefit analysis studies in Australia. The data is of particular interest for the discounting of projects that create monetary costs and benefits in the distant future.

  10. Discounting the distant future-Data on Australian discount rates estimated by a stochastic interest rate model.

    Science.gov (United States)

    Truong, Chi; Trück, Stefan

    2017-04-01

    Data on certainty equivalent discount factors and discount rates for stochastic interest rates in Australia are provided in this paper. The data has been used for the analysis of investments into climate adaptation projects in ׳It׳s not now or never: Implications of investment timing and risk aversion on climate adaptation to extreme events ׳ (Truong and Trück, 2016) [3] and can be used for other cost-benefit analysis studies in Australia. The data is of particular interest for the discounting of projects that create monetary costs and benefits in the distant future.

  11. Monetary rewards modulate inhibitory control

    Directory of Open Access Journals (Sweden)

    Paula Marcela Herrera

    2014-05-01

    Full Text Available The ability to override a dominant response, often referred to as behavioural inhibiton, is considered a key element of executive cognition. Poor behavioural inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioural inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/Nogo and Stop Signal Tasks. Several studies have reported a positive modulatory effect of reward on the performance of such tasks in pathological conditions such as substance abuse, pathological gambling, and ADHD. However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory paradigms are rare and consequently, little is known about the finer grained relationship between motivation and self-control. Here, we probed the effect of reward and reward magnitude on behavioural inhibition using two modified version of the widely used Stop Signal Task. The first task compared no reward with reward, whilst the other compared two different reward magnitudes. The reward magnitude effect was confirmed by the second study, whereas it was less compelling in the first study, possibly due to the effect of having no reward in some conditions. In addition, our results showed a kick start effect over global performance measures. More specifically, there was a long lasting improvement in performance throughout the task, when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate that individuals’ behavioural inhibition capacities are dynamic not static because they are modulated by the reward magnitude and initial reward history of the task at hand.

  12. Impaired reward responsiveness in schizophrenia.

    Science.gov (United States)

    Taylor, Nicholas; Hollis, Jeffrey P; Corcoran, Sarah; Gross, Robin; Cuthbert, Bruce; Swails, Lisette W; Duncan, Erica

    2018-03-08

    Anhedonia is a core negative symptom of schizophrenia. Schizophrenia patients report largely intact pleasure in consuming rewards, but have impairments in generating motivated behavior to pursue rewards, and show reduced fMRI activation of the reward pathway during presentation of rewarded stimuli. A computer based task measuring the development of a response bias in favor of rewarded stimuli permits assessment of reward-induced motivation. We hypothesized that subjects with schizophrenia would be impaired on this task. 58 schizophrenia subjects (SCZ) and 52 healthy controls (CON) were studied with a signal detection task to assess reward responsiveness. In multiple trials over three blocks subjects were asked to correctly identify two stimuli that were paired with unequal chance of monetary reward. The critical outcome variable was response bias, the development of a greater percent correct identification of the stimulus that was rewarded more often. An ANOVA on response bias with Block as a repeated-measures factor and Diagnosis as a between-group factor indicated that SCZ subjects achieved a lower bias to rewarded stimuli than CON subjects (F(1,105)=8.82, p=0.004, η 2 =0.078). Post hoc tests indicated that SCZ subjects had significantly impaired bias in Block 1 (p=0.002) and Block 2 (p=0.05), indicating that SCZ were slower to achieve normal levels of bias during the session. SCZ subjects were slower to develop response bias to rewarded stimuli than CON subjects. This finding is consonant with the hypothesis that people with schizophrenia have a blunted capacity to modify behavior in response to reward. Copyright © 2018. Published by Elsevier B.V.

  13. A social discounting model based on Tsallis’ statistics

    Science.gov (United States)

    Takahashi, Taiki

    2010-09-01

    Social decision making (e.g. social discounting and social preferences) has been attracting attention in economics, econophysics, social physics, behavioral psychology, and neuroeconomics. This paper proposes a novel social discounting model based on the deformed algebra developed in the Tsallis’ non-extensive thermostatistics. Furthermore, it is suggested that this model can be utilized to quantify the degree of consistency in social discounting in humans and analyze the relationships between behavioral tendencies in social discounting and other-regarding economic decision making under game-theoretic conditions. Future directions in the application of the model to studies in econophysics, neuroeconomics, and social physics, as well as real-world problems such as the supply of live organ donations, are discussed.

  14. Review of assessment methods discount rate in investment analysis

    Directory of Open Access Journals (Sweden)

    Yamaletdinova Guzel Hamidullovna

    2011-08-01

    Full Text Available The article examines the current methods of calculating discount rate in investment analysis and business valuation, as well as analyzes the key problems using various techniques in terms of the Russian economy.

  15. Welcome to professional courtesy discounts: the medical community's pandora's box.

    Science.gov (United States)

    Winkler, A D

    1998-01-01

    Recent government regulations on fraud and abuse have transformed the tradition of professional courtesy discounts into a legal minefield threatening to explode on the uninformed medical provider. This paper offers an understanding of the issues involved and provider options.

  16. Online Discount Luxury: In Search of Guilty Customers

    Directory of Open Access Journals (Sweden)

    Dr. Nikolai Ostapenko

    2013-07-01

    Full Text Available Discount luxury sites mainly serve as online platform for the “flash sales” method, offering limited-time availability of high fashion, travel, home décor, and culinary bargains to its members. The idea of moving “sample sales” online was first realized on a European website, Vente-Privee.com, which now has more than 13 million customers. Following Gilt’s introduction in the United States, flash sales skyrocketed and led to the launching of many new sites, which have proved popular both with consumers seeking impressive discounts on luxury goods, and with exclusive brands wanting to unload their unsold stock quickly. Recently we found that many of the sites are going through the customer fatigue stage, and their further success requires more than just deep discounts. The article reviews possible new business strategies and models within discount luxury retail segment mainly based upon experience of the Gilt Groupe.

  17. Discounting of quantity surveying fees in South Africa

    African Journals Online (AJOL)

    by clients have forced Quantity Surveying firms into competition with ... Furthermore, 43% of consulting engineering firms were discounting their fees at a rate of .... Quantity. Surveying services are also offered in the fields of dispute resolution,.

  18. Dual discounting in cost-benefit analysis for environmental impacts

    International Nuclear Information System (INIS)

    Kula, Erhun; Evans, David

    2011-01-01

    Discounting has been a long-established intertemporal efficiency tool in cost-benefit analysis which focuses on project selection at communal level with a view to maximising the social welfare. However, with the relentless growth in environmental stress that, in good parts, stems from investment projects the established criterion in discounting appears to be inadequate especially when environmental issues are taken into consideration. This paper looks at how dual focus on efficiency and sustainability can be achieved by using dual discounting, i.e. discounting environmental benefits separately and differently from other costs and benefits and applies this alternative criterion to an afforestation scheme in the United Kingdom which contains carbon sequestration in addition to timber benefits.

  19. INFLUENCE OF DISCOUNT PRICE ANNOUNCEMENTS ON CONSUMER’S BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Giuliana Isabella

    2012-10-01

    Full Text Available The theoretical framework that underpins this research study is based on the Prospect Theory formulated by Kahneman and Tversky, and Thaler´s Mental Accounting Theory. The research aims to evaluate the consumers’ behavior when different patterns of discount are offered (in percentage and absolute value and for larger and smaller discounts. Two experiments were conducted to explore these patterns of behavior and the results that were obtained supported the view that the framing effect was a common occurrence. The patterns of choice of individuals in a sample were found to be different due to changes in the ways discounts were offered. This can be explained by the various ways of presenting discount rates that had an impact on the influence of purchase intentions, recommendations and quality perception.

  20. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  1. Commitment to self-rewards

    DEFF Research Database (Denmark)

    Koch, Alexander; Nafziger, Julia

    People often overcome self-control problems by promising to reward themselves for accomplishing a task. Such strategies based on self-administered rewards however require the person to believe that she would indeed deny herself the reward if she should fail to achieve the desired outcome. Drawing...... on Koszegi and Rabin's (2006) model of endogenous reference point formation, we show how a rational forward-looking individual can achieve such internal commitment. But our results also demonstrate the limitations of self regulation based on self-rewards....

  2. A Rational Model of the Closed-End Fund Discount

    OpenAIRE

    Jonathan Berk; Richard Stanton

    2004-01-01

    The discount on closed-end funds is widely accepted as proof of investor irrationality. We show,however, that a parsimonious rational model can generate a discount that exhibits many of the characteristics observed in practice. The only required features of the model are that managers have (imperfectly observable) ability to generate excess returns; they sign long-term contracts guaranteeing them a fee each year equal to a fixed fraction of assets under management; and they can leave to earn ...

  3. Discount Rate and Timber Rotation: the Case of Eucalyptus Saligna

    OpenAIRE

    Camilo Restrepo; Mauricio Alviar

    2010-01-01

    Eucalyptus is one of the most important economical and environmental species in Colombia. The main goal of this article is to study the relationship between the discount rate and the year of Eucalyptus Saligna optimal harvest, through the Fisher and Hotelling’s method. The methodology consists of calculating the maximum Net Present Value and performing a sensitivity analysis between the year of harvest and the discount rate. The area of study is located in the eastern region of the state of A...

  4. An Adjusted Discount Rate Model for Fuel Cycle Cost Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. K.; Kang, G. B.; Ko, W. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Owing to the diverse nuclear fuel cycle options available, including direct disposal, it is necessary to select the optimum nuclear fuel cycles in consideration of the political and social environments as well as the technical stability and economic efficiency of each country. Economic efficiency is therefore one of the significant evaluation standards. In particular, because nuclear fuel cycle cost may vary in each country, and the estimated cost usually prevails over the real cost, when evaluating the economic efficiency, any existing uncertainty needs to be removed when possible to produce reliable cost information. Many countries still do not have reprocessing facilities, and no globally commercialized HLW (High-level waste) repository is available. A nuclear fuel cycle cost estimation model is therefore inevitably subject to uncertainty. This paper analyzes the uncertainty arising out of a nuclear fuel cycle cost evaluation from the viewpoint of a cost estimation model. Compared to the same discount rate model, the nuclear fuel cycle cost of a different discount rate model is reduced because the generation quantity as denominator in Equation has been discounted. Namely, if the discount rate reduces in the back-end process of the nuclear fuel cycle, the nuclear fuel cycle cost is also reduced. Further, it was found that the cost of the same discount rate model is overestimated compared with the different discount rate model as a whole.

  5. An Adjusted Discount Rate Model for Fuel Cycle Cost Estimation

    International Nuclear Information System (INIS)

    Kim, S. K.; Kang, G. B.; Ko, W. I.

    2013-01-01

    Owing to the diverse nuclear fuel cycle options available, including direct disposal, it is necessary to select the optimum nuclear fuel cycles in consideration of the political and social environments as well as the technical stability and economic efficiency of each country. Economic efficiency is therefore one of the significant evaluation standards. In particular, because nuclear fuel cycle cost may vary in each country, and the estimated cost usually prevails over the real cost, when evaluating the economic efficiency, any existing uncertainty needs to be removed when possible to produce reliable cost information. Many countries still do not have reprocessing facilities, and no globally commercialized HLW (High-level waste) repository is available. A nuclear fuel cycle cost estimation model is therefore inevitably subject to uncertainty. This paper analyzes the uncertainty arising out of a nuclear fuel cycle cost evaluation from the viewpoint of a cost estimation model. Compared to the same discount rate model, the nuclear fuel cycle cost of a different discount rate model is reduced because the generation quantity as denominator in Equation has been discounted. Namely, if the discount rate reduces in the back-end process of the nuclear fuel cycle, the nuclear fuel cycle cost is also reduced. Further, it was found that the cost of the same discount rate model is overestimated compared with the different discount rate model as a whole

  6. A novel multi-item joint replenishment problem considering multiple type discounts.

    Directory of Open Access Journals (Sweden)

    Ligang Cui

    Full Text Available In business replenishment, discount offers of multi-item may either provide different discount schedules with a single discount type, or provide schedules with multiple discount types. The paper investigates the joint effects of multiple discount schemes on the decisions of multi-item joint replenishment. In this paper, a joint replenishment problem (JRP model, considering three discount (all-unit discount, incremental discount, total volume discount offers simultaneously, is constructed to determine the basic cycle time and joint replenishment frequencies of multi-item. To solve the proposed problem, a heuristic algorithm is proposed to find the optimal solutions and the corresponding total cost of the JRP model. Numerical experiment is performed to test the algorithm and the computational results of JRPs under different discount combinations show different significance in the replenishment cost reduction.

  7. Monetary rewards influence retrieval orientations.

    Science.gov (United States)

    Halsband, Teresa M; Ferdinand, Nicola K; Bridger, Emma K; Mecklinger, Axel

    2012-09-01

    Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24 h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding.

  8. Time discounting and pain anticipation. Experimental evidence

    Directory of Open Access Journals (Sweden)

    Brañas Garza, Pablo

    2012-03-01

    Full Text Available This paper deals with pain anticipation experienced before medical procedures. our experimental results show that individuals with lower time discount factors are more prone to suffer pain in advance. We provide a framework to rationalize the connection between pain anticipation and impatience. in this set up, more impatient subjects, who only value very near events, mainly take into account the present negative effects of medical procedures (the costs, whereas more patient individuals have a net positive valuation of medical events, given that they are able to value both the cost incurred now and all the benefits to be accrued in the future.

    Este artículo trata de la anticipación del dolor experimentada antes de los procedimientos médicos. nuestros resultados experimentales muestran que los individuos con factor de descuento temporal más bajo son más proclives a sufrir dolor por adelantado. el artículo proporciona un marco en el que racionalizar la relación existente entre impaciencia y anticipación del dolor. en este marco, los sujetos más impacientes, que evalúan sólo los eventos muy próximos en el tiempo, focalizan su atención principalmente en los efectos negativos de los procedimientos médicos (sólo los costes, mientras que los individuos más pacientes tienen una valoración neta positiva de los actos médicos puesto que valoran tanto el coste en el que se incurre en el presente como los beneficios que se obtendrán en el futuro.

  9. Estimation of social discount rate for Lithuania

    Directory of Open Access Journals (Sweden)

    Vilma Kazlauskiene

    2016-09-01

    Full Text Available Purpose of the article: The paper seeks to analyse the problematics of estimation of the social discount rate (SDR. The SDR is the critical parameter of cost-benefit analysis, which allows calculating the present value of cost and the benefit of public sector investment projects. Incorrect choice of the SDR can lead to the realisation of ineffective public project or conversely, cost-effective project will be rejected. The relevance of this problem analysis is determined by discussions and different viewpoints of scientists on the choice of the most appropriate approach to determine the SDR and absence of methodically based the SDR on the national level of Lithuania. Methodology/methods: The research is performed by the scientific and methodical literature analysis, systematization, time series and regression analysis. Scientific aim: The aim of the article is to calculate the SDR based on the statistical data of Lithuania. Findings: The analysis of methods of SDR determination, as well as the researches performed by foreign researchers, allows stating that the social rate of time preference (SRTP approach is the most appropriate. The SDR, calculated by the SRTP approach, reflects the main purpose of public investment projects, i.e. to enhance social benefit for society, the best. The analyses of SDR determination practice of the foreign countries shows that the SDR level should not be universal for all states. Each country should calculate the SDR based on its own data and apply it for the assessment of public projects. Conclusions: The calculated SDR for Lithuania using the SRTP approach varies between 3.5% and 4.3%. Although it is lower than 5% that is offered by European Commission, this rate is based on the statistical data of Lithuania and should be used for the assessment of the national public projects. Applicatio

  10. Model Checking Multivariate State Rewards

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Nielson, Flemming; Nielson, Hanne Riis

    2010-01-01

    We consider continuous stochastic logics with state rewards that are interpreted over continuous time Markov chains. We show how results from multivariate phase type distributions can be used to obtain higher-order moments for multivariate state rewards (including covariance). We also generalise...

  11. Combining Environmental and Spatial Discount Rates for Valuation of Assets According to International Financial Reporting Standards

    Directory of Open Access Journals (Sweden)

    Jaunzeme Justine Sophia

    2016-06-01

    Full Text Available Application of discount rate in finance and accounting is founded on the concept of time value of money. Discounted cash flow model is widely used for asset valuation under the International Financial Reporting Standards (in abbreviation, IFRS. The discount rate applied in valuation models normally is the best rate of return that investors would earn alternative investments. With emergence of ecological economics as a separate branch of economics, the concept of ecological (or in other words, environmental discount rate has been elaborated. Muller (2013 in his paper ‘The Discounting Confusion: an Ecological Economics Perspective’, argues that traditional discounting can undermine long-term sustainability of the economy. In his work, Frank G. Muller considered adjusting the traditional discount rate in order to arrive at an environmental discount rate, which would help to ensure the sustainability of the economy. Hannon (2001 and Perrings (2001 in their paper ‘An Introduction to Spatial Discounting’ consider another variation of the discount rate - spatial discount rate. Spatial discount rate represents the rate at which the diffusion of environmental effects of economic activities is discounted over space. By February 2016, neither the application of environmental nor spatial discount rates under IFRS has been considered. The purpose of this paper is to analyse the implications that environmental and spatial discounting would have for the application of discounted cash flow model according to IFRS. The research methods applied are methods of economic analysis and synthesis.

  12. Altered neural processing of reward and punishment in adolescents with Major Depressive Disorder.

    Science.gov (United States)

    Landes, I; Bakos, S; Kohls, G; Bartling, J; Schulte-Körne, G; Greimel, E

    2018-05-01

    Altered reward and punishment function has been suggested as an important vulnerability factor for the development of Major Depressive Disorder (MDD). Prior ERP studies found evidence for neurophysiological dysfunctions in reinforcement processes in adults with MDD. To date, only few ERP studies have examined the neural underpinnings of reinforcement processing in adolescents diagnosed with MDD. The present event-related potential (ERP) study aimed to investigate neurophysiological mechanisms of anticipation and consumption of reward and punishment in adolescents with MDD in one comprehensive paradigm. During ERP recording, 25 adolescents with MDD and 29 healthy controls (12-17 years) completed a Monetary Incentive Delay Task comprising both a monetary reward and a monetary punishment condition. During anticipation, the cue-P3 signaling attentional allocation was recorded. During consumption, the feedback-P3 and Reward Positivity (RewP) were recorded to capture attentional allocation and outcome evaluation, respectively. Compared to controls, adolescents with MDD showed prolonged cue-P3 latencies to reward cues. Furthermore, unlike controls, adolescents with MDD displayed shorter feedback-P3 latencies in the reward versus punishment condition. RewPs did not differ between groups. It remains unanswered whether the observed alterations in adolescent MDD represent a state or trait. Delayed neural processing of reward cues corresponds to the clinical presentation of adolescent MDD with reduced motivational tendencies to obtain rewards. Relatively shorter feedback-P3 latencies in the reward versus punishment condition could indicate a high salience of performance-contingent reward. Frequent exposure of negatively biased adolescents with MDD to performance-contingent rewards might constitute a promising intervention approach. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Decision-making and addiction (part II): myopia for the future or hypersensitivity to reward?

    Science.gov (United States)

    Bechara, Antoine; Dolan, Sara; Hindes, Andrea

    2002-01-01

    On a decision-making instrument known as the "gambling task" (GT), a subgroup of substance dependent individuals (SDI) opted for choices that yield high immediate gains in spite of higher future losses. This resembles the behavior of patients with ventromedial (VM) prefrontal cortex lesions. In this study, we addressed the possibility that hypersensitivity to reward may account for the "myopia" for the future in this subgroup of SDI. We used a variant version of the GT, in which the good decks yielded high immediate punishment but higher delayed reward. The bad decks yielded low immediate punishment and lower delayed reward. We measured the skin conductance response (SCR) of subjects after receiving reward (reward SCR) and during their pondering from which deck to choose (anticipatory SCR). A subgroup of SDI who was not impaired on the original GT performed normally on the variant GT. The subgroup of SDI who was impaired on the original GT showed two levels of performance on the variant GT. One subgroup (36% of the sample) performed poorly on the variant GT, and showed similar behavioral and physiological impairments to VM patients. The other subgroup of SDI (64% of the sample) performed normally on the variant task, but had abnormally large physiological responses to reward, i.e. large SCR after receiving reward (reward SCR) and large SCR in anticipation of outcomes that yield large reward. Thus, the combined cognitive and physiological approach of assessing decision-making characterizes three sub-populations of SDI. One sub-population is without impairments that can be detected by any measure of the GT paradigm. Another sub-population is similar to VM patients in that they are insensitive to the future, both positive and negative. A third sub-population is hypersensitive to reward, so that the presence or the prospect of receiving, reward dominates their behavior.

  14. Norplant debate: dollars v. sense. Is Norplant discount in U.S. too little, too late?

    Science.gov (United States)

    1994-01-01

    At a Congressional hearing of the pricing strategy for Norplant, and after several family planning specialists testified that Norplant's cost ($365) makes it inaccessible to many US women, Wyeth-Ayerst announced that, in 2 years, it would provide Norplant to public sector family planning clinics at a discount price. Just 1.4% of clients at Planned Parenthood clinics choose Norplant, because it is too costly. While Title X clinic officials are pleased with this announcement, many family planning providers wonder what the manufacturer's motives are. The president of the National Family Planning and Reproductive Health Association believes that the announcement is a press ploy. The Wyeth spokesperson said the original licensing agreement with the Population Council allowed a public sector price 5 years after Norplant's introduction in the US market. The 5-year delay was intended to build private sector support and to allow Wyeth to recover its marketing and training expenses. Wyeth also wanted Norplant to become a mainstream contraceptive, so it became concerned about the private sector. Yet, the law requires a 15% rebate for qualified public health clinics now. Few family planners expressed praise for Wyeth, since it revealed no details on the public sector price. Further, health care reform may alter drug pricing before the 2-year period. In early 1994, Wyeth's exclusive patent on Norplant and on levonorgestrel expires, allowing other companies to enter the implant market. Yet, other companies need at least 1 year to negotiate with the US Food and Drug Administration for approval, thereby allowing Wyeth a window to dominate the market. Thus, by the time the 2 years is up, the discount will have no meaning. Family planners have criticized Wyeth for not offering a public sector discount for a long time, especially since public funds contributed to Norplant's development. Wyeth's only contribution was levonorgestrel. It allowed the Population Council to use

  15. Selection of a discount rate for use in NRC regulatory analyses and application of discount rates to future averted health effects

    International Nuclear Information System (INIS)

    Paananen, O.H.; Hendrickson, P.L.

    1993-01-01

    The principal objective of this report is to provide background information and recommendations on the use of discount rates in the regulatory analysis process. The report focuses on two issues selecting the appropriate discount rate or rates to use when conducting a regulatory analysis, and applying the selected discount rate to future health-related benefits estimated to result from alternative regulatory actions

  16. Tracking the Discount: Tuition Discount Rates, Net Tuition Revenue, and Efforts to Inform Institutional Practices. Professional File. Article 133, Fall 2013

    Science.gov (United States)

    Davis, Natalie Pullaro; Redd, Kenneth E.

    2013-01-01

    This article uses findings from the 2012 Tuition Discounting Study (TDS) conducted by the National Association of College and University Business Officers (NACUBO) to provide a framework for institutional researchers to develop and adapt their own custom tuition discounting definitions and formulas. Under tuition discounting, colleges and…

  17. The Effect of Cognitive Restructuring on Delay of Gratification.

    Science.gov (United States)

    Nisan, Mordecai; Koriat, Asher

    1984-01-01

    Two experiments evaluated predictions derived from a cognitive-developmental approach to delay of gratification. In the first, kindergarten children were asked to make a choice between a small immediate and a large delayed reward. In the second, children were presented with either an objective-rational or a subjective-emotional argument…

  18. Risk and reward

    International Nuclear Information System (INIS)

    Kellas, G.K.; Hodgshon, S.G.

    1992-01-01

    This paper looks at the problems facing the international oil explorationist and host Governments in 1992, under a cloud of low oil prices and falling company profits, yet with more quality acreage available worldwide than for many years, especially with the emergence of the CIS states as prospective hunting grounds for the western oil company. Given the extent of the spread of opportunities available to companies and recognition of the increasing need to justify, on economic grounds, progress with any licence application this paper suggests two approaches that companies can adopt to rank the opportunities available, and maximize the value, on an after risk basis, of their (limited) international exploration budget : subjective rating by factor or the Risk/Reward balance. Both of these approaches include measures of prospectivity and measures of local cost and fiscal effects in providing an overall exploration rating which can be used by companies to rank the available opportunities

  19. ATLAS rewards industry

    CERN Multimedia

    2006-01-01

    Showing excellence in mechanics, electronics and cryogenics, three industries are honoured for their contributions to the ATLAS experiment. Representatives of the three award-wining companies after the ceremony. For contributing vital pieces to the ATLAS puzzle, three industries were recognized on Friday 5 May during a supplier awards ceremony. After a welcome and overview of the ATLAS experiment by spokesperson Peter Jenni, CERN Secretary-General Maximilian Metzger stressed the importance of industry to CERN's scientific goals. Close interaction with CERN was a key factor in the selection of each rewarded company, in addition to the high-quality products they delivered to the experiment. Alu Menziken Industrie AG, of Switzerland, was honoured for the production of 380,000 aluminium tubes for the Monitored Drift Tube Chambers (MDT). As Giora Mikenberg, the Muon System Project Leader stressed, the aluminium tubes were delivered on time with an extraordinary quality and precision. Between October 2000 and Jan...

  20. Reward deficiency and anti-reward in pain chronification.

    Science.gov (United States)

    Borsook, D; Linnman, C; Faria, V; Strassman, A M; Becerra, L; Elman, I

    2016-09-01

    Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between-systems neuroadaptation involving over-recruitment of key limbic structures (e.g., the central and basolateral amygdala nuclei, the bed nucleus of the stria terminalis, the lateral tegmental noradrenergic nuclei of the brain stem, the hippocampus and the habenula) responsible for massive outpouring of stressogenic neurochemicals (e.g., norepinephrine, corticotropin releasing factor, vasopressin, hypocretin, and substance P) giving rise to such negative affective states as anxiety, fear and depression. We propose here the Combined Reward deficiency and Anti-reward Model (CReAM), in which biopsychosocial variables modulating brain reward, motivation and stress functions can interact in a 'downward spiral' fashion to exacerbate the intensity, chronicity and comorbidities of chronic pain syndromes (i.e., pain chronification). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. 'Proactive' use of cue-context congruence for building reinforcement learning's reward function.

    Science.gov (United States)

    Zsuga, Judit; Biro, Klara; Tajti, Gabor; Szilasi, Magdolna Emma; Papp, Csaba; Juhasz, Bela; Gesztelyi, Rudolf

    2016-10-28

    Reinforcement learning is a fundamental form of learning that may be formalized using the Bellman equation. Accordingly an agent determines the state value as the sum of immediate reward and of the discounted value of future states. Thus the value of state is determined by agent related attributes (action set, policy, discount factor) and the agent's knowledge of the environment embodied by the reward function and hidden environmental factors given by the transition probability. The central objective of reinforcement learning is to solve these two functions outside the agent's control either using, or not using a model. In the present paper, using the proactive model of reinforcement learning we offer insight on how the brain creates simplified representations of the environment, and how these representations are organized to support the identification of relevant stimuli and action. Furthermore, we identify neurobiological correlates of our model by suggesting that the reward and policy functions, attributes of the Bellman equitation, are built by the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC), respectively. Based on this we propose that the OFC assesses cue-context congruence to activate the most context frame. Furthermore given the bidirectional neuroanatomical link between the OFC and model-free structures, we suggest that model-based input is incorporated into the reward prediction error (RPE) signal, and conversely RPE signal may be used to update the reward-related information of context frames and the policy underlying action selection in the OFC and ACC, respectively. Furthermore clinical implications for cognitive behavioral interventions are discussed.

  2. Estimating implied rates of discount in healthcare decision-making.

    Science.gov (United States)

    West, R R; McNabb, R; Thompson, A G H; Sheldon, T A; Grimley Evans, J

    2003-01-01

    To consider whether implied rates of discounting from the perspectives of individual and society differ, and whether implied rates of discounting in health differ from those implied in choices involving finance or "goods". The study comprised first a review of economics, health economics and social science literature and then an empirical estimate of implied rates of discounting in four fields: personal financial, personal health, public financial and public health, in representative samples of the public and of healthcare professionals. Samples were drawn in the former county and health authority district of South Glamorgan, Wales. The public sample was a representative random sample of men and women, aged over 18 years and drawn from electoral registers. The health professional sample was drawn at random with the cooperation of professional leads to include doctors, nurses, professions allied to medicine, public health, planners and administrators. The literature review revealed few empirical studies in representative samples of the population, few direct comparisons of public with private decision-making and few direct comparisons of health with financial discounting. Implied rates of discounting varied widely and studies suggested that discount rates are higher the smaller the value of the outcome and the shorter the period considered. The relationship between implied discount rates and personal attributes was mixed, possibly reflecting the limited nature of the samples. Although there were few direct comparisons, some studies found that individuals apply different rates of discount to social compared with private comparisons and health compared with financial. The present study also found a wide range of implied discount rates, with little systematic effect of age, gender, educational level or long-term illness. There was evidence, in both samples, that people chose a lower rate of discount in comparisons made on behalf of society than in comparisons made for

  3. Dimensional psychiatry: reward dysfunction and depressive mood across psychiatric disorders.

    Science.gov (United States)

    Hägele, Claudia; Schlagenhauf, Florian; Rapp, Michael; Sterzer, Philipp; Beck, Anne; Bermpohl, Felix; Stoy, Meline; Ströhle, Andreas; Wittchen, Hans-Ulrich; Dolan, Raymond J; Heinz, Andreas

    2015-01-01

    A dimensional approach in psychiatry aims to identify core mechanisms of mental disorders across nosological boundaries. We compared anticipation of reward between major psychiatric disorders, and investigated whether reward anticipation is impaired in several mental disorders and whether there is a common psychopathological correlate (negative mood) of such an impairment. We used functional magnetic resonance imaging (fMRI) and a monetary incentive delay (MID) task to study the functional correlates of reward anticipation across major psychiatric disorders in 184 subjects, with the diagnoses of alcohol dependence (n = 26), schizophrenia (n = 44), major depressive disorder (MDD, n = 24), bipolar disorder (acute manic episode, n = 13), attention deficit/hyperactivity disorder (ADHD, n = 23), and healthy controls (n = 54). Subjects' individual Beck Depression Inventory-and State-Trait Anxiety Inventory-scores were correlated with clusters showing significant activation during reward anticipation. During reward anticipation, we observed significant group differences in ventral striatal (VS) activation: patients with schizophrenia, alcohol dependence, and major depression showed significantly less ventral striatal activation compared to healthy controls. Depressive symptoms correlated with dysfunction in reward anticipation regardless of diagnostic entity. There was no significant correlation between anxiety symptoms and VS functional activation. Our findings demonstrate a neurobiological dysfunction related to reward prediction that transcended disorder categories and was related to measures of depressed mood. The findings underline the potential of a dimensional approach in psychiatry and strengthen the hypothesis that neurobiological research in psychiatric disorders can be targeted at core mechanisms that are likely to be implicated in a range of clinical entities.

  4. Individual differences in regulatory focus predict neural response to reward.

    Science.gov (United States)

    Scult, Matthew A; Knodt, Annchen R; Hanson, Jamie L; Ryoo, Minyoung; Adcock, R Alison; Hariri, Ahmad R; Strauman, Timothy J

    2017-08-01

    Although goal pursuit is related to both functioning of the brain's reward circuits and psychological factors, the literatures surrounding these concepts have often been separate. Here, we use the psychological construct of regulatory focus to investigate individual differences in neural response to reward. Regulatory focus theory proposes two motivational orientations for personal goal pursuit: (1) promotion, associated with sensitivity to potential gain, and (2) prevention, associated with sensitivity to potential loss. The monetary incentive delay task was used to manipulate reward circuit function, along with instructional framing corresponding to promotion and prevention in a within-subject design. We observed that the more promotion oriented an individual was, the lower their ventral striatum response to gain cues. Follow-up analyses revealed that greater promotion orientation was associated with decreased ventral striatum response even to no-value cues, suggesting that promotion orientation may be associated with relatively hypoactive reward system function. The findings are also likely to represent an interaction between the cognitive and motivational characteristics of the promotion system with the task demands. Prevention orientation did not correlate with ventral striatum response to gain cues, supporting the discriminant validity of regulatory focus theory. The results highlight a dynamic association between individual differences in self-regulation and reward system function.

  5. Temporal dynamics of reward anticipation in the human brain.

    Science.gov (United States)

    Zhang, Yuanyuan; Li, Qi; Wang, Zhao; Liu, Xun; Zheng, Ya

    2017-09-01

    Reward anticipation is a complex process including cue evaluation, motor preparation, and feedback anticipation. The present study investigated whether these psychological processes were dissociable on neural dynamics in terms of incentive valence and approach motivation. We recorded EEG when participants were performing a monetary incentive delay task, and found a cue-P3 during the cue-evaluation stage, a contingent negative variation (CNV) during the motor-preparation stage, and a stimulus-preceding negativity (SPN) during the feedback-anticipation stage. Critically, both the cue-P3 and SPN exhibited an enhanced sensitivity to gain versus loss anticipation, which was not observed for the CNV. Moreover, both the cue-P3 and SPN, instead of the CNV, for gain anticipation selectively predicted the participants' approach motivation as measured in a following effort expenditure for rewards task, particularly when reward uncertainty was maximal. Together, these results indicate that reward anticipation consists of several sub-stages, each with distinct functional significance, thus providing implications for neuropsychiatric diseases characterized by dysfunction in anticipatory reward processing. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Delayed Ejaculation

    Science.gov (United States)

    ... cases, it is due to a combination of physical and psychological concerns. Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication ...

  7. Delayed growth

    Science.gov (United States)

    ... Slow rate of growth; Retarded growth and development; Growth delay Images Toddler development References Cooke DW, Divall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Polonsky KS, Larsen PR, ...

  8. Maximizing the Spread of Influence via Generalized Degree Discount.

    Science.gov (United States)

    Wang, Xiaojie; Zhang, Xue; Zhao, Chengli; Yi, Dongyun

    2016-01-01

    It is a crucial and fundamental issue to identify a small subset of influential spreaders that can control the spreading process in networks. In previous studies, a degree-based heuristic called DegreeDiscount has been shown to effectively identify multiple influential spreaders and has severed as a benchmark method. However, the basic assumption of DegreeDiscount is not adequate, because it treats all the nodes equally without any differences. To consider a general situation in real world networks, a novel heuristic method named GeneralizedDegreeDiscount is proposed in this paper as an effective extension of original method. In our method, the status of a node is defined as a probability of not being influenced by any of its neighbors, and an index generalized discounted degree of one node is presented to measure the expected number of nodes it can influence. Then the spreaders are selected sequentially upon its generalized discounted degree in current network. Empirical experiments are conducted on four real networks, and the results show that the spreaders identified by our approach are more influential than several benchmark methods. Finally, we analyze the relationship between our method and three common degree-based methods.

  9. Description, prescription and the choice of discount rates

    International Nuclear Information System (INIS)

    Baum, Seth D.

    2009-01-01

    The choice of discount rates is a key issue in the analysis of long-term societal issues, in particular environmental issues such as climate change. Approaches to choosing discount rates are generally placed into two categories: the descriptive approach and the prescriptive approach. The descriptive approach is often justified on grounds that it uses a description of how society discounts instead of having analysts impose their own discounting views on society. This paper analyzes the common forms of the descriptive and prescriptive approaches and finds that, in contrast with customary thinking, both forms are equally descriptive and prescriptive. The prescriptions concern who has standing (i.e. who is included) in society, how the views of these individuals are measured, and how the measurements are aggregated. Such prescriptions are necessary to choose from among the many possible descriptions of how society discounts. The descriptions are the measurements made given a choice of measurement technique. Thus, the labels 'descriptive approach' and 'prescriptive approach' are deeply misleading, as analysts cannot avoid imposing their own views on society. (author)

  10. Interindividual variability in functional connectivity as long-term correlate of temporal discounting.

    Directory of Open Access Journals (Sweden)

    Cinzia Calluso

    Full Text Available During intertemporal choice (IT future outcomes are usually devaluated as a function of the delay, a phenomenon known as temporal discounting (TD. Based on task-evoked activity, previous neuroimaging studies have described several networks associated with TD. However, given its relevance for several disorders, a critical challenge is to define a specific neural marker able to predict TD independently of task execution. To this aim, we used resting-state functional connectivity MRI (fcMRI and measured TD during economic choices several months apart in 25 human subjects. We further explored the relationship between TD, impulsivity and decision uncertainty by collecting standard questionnaires on individual trait/state differences. Our findings indicate that fcMRI within and between critical nodes of task-evoked neural networks associated with TD correlates with discounting behavior measured a long time afterwards, independently of impulsivity. Importantly, the nodes form an intrinsic circuit that might support all the mechanisms underlying TD, from the representation of subjective value to choice selection through modulatory effects of cognitive control and episodic prospection.

  11. Addictive drugs and brain stimulation reward.

    Science.gov (United States)

    Wise, R A

    1996-01-01

    Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.

  12. Employee Reward Systems in Organizations

    Directory of Open Access Journals (Sweden)

    Došenović Dragana

    2016-06-01

    Full Text Available Employee rewarding is one of the activities of human resource management concerning the management of money, goods and services that employees receive from their employer in exchange for their work. Given that a properly designed reward system is one of the conditions for a stable business, successful performance of work activities and the achievement of set objectives in each organization, the basic theme of this paper is the employee reward system, with a special focus on different elements of it. The purpose of this paper is to describe the role and significance of the observed system and to draw attention to its role in employee’s motivation.

  13. Negative Symptoms and Reward Disturbances in Schizophrenia Before and After Antipsychotic Monotherapy

    DEFF Research Database (Denmark)

    Nielsen, Mette Ødegaard; Rostrup, Egill; Broberg, Brian Villumsen

    2018-01-01

    BACKGROUND: Negative symptoms (NS) are a central part of the symptomatology of schizophrenia, which is highly correlated to the functional outcome. Disturbances of the brain reward system are suggested to be central in the pathogenesis of NS by decreasing motivation and hedonic experiences...... = .001). DISCUSSION: Patients improving in NS score had a less aberrant reward system at baseline, but reward related activity was reduced over time. Patients not improving in NS showed decreased striatal reward-activity at baseline, which improved over time. Whether this is associated with alteration....... In this study, we compared reward-related brain activity in patients improving and not improving in NS after treatment with amisulpride. METHODS: Thirty-nine antipsychotic-naive patients and 49 healthy controls completed functional magnetic resonance imaging with a modified monetary incentive delay task...

  14. The Role of Reward Expectations for Prospective Memory : An investigation with functional magnetic resonance imaging

    OpenAIRE

    Gäbel, Andrea

    2010-01-01

    Prospective memory is the ability to remember to carry out an intended action after a delay. However, it remains unclear how motivational aspects of the intended action,such as reward expectations, are integrated into the processes subserving intact prospective memory. The goal of this dissertation is to investigate the effects of motivational incentives on prospective memory on the behavioral and on the neural level, while taking into account individual differences in reward sensitivity and ...

  15. Discount factor in planning decision of electric sector

    International Nuclear Information System (INIS)

    Becker, J.L.; Maurer, L.T.A.

    1990-01-01

    Researchers and technicians have been giving a lot of attention to the issue of discount factor in planning in the electric sector. In this paper we review the most important points under consideration, attempting to broaden the discussion and stimulate the creativity of the technicians involved with the sector. There appears to be an emerging consensus that the discount factor to be used must consider the capital costs associated with the main financial sources utilized. The traditional factor of 10% per year must be re-evaluated and augmented, in order to best reflect long range economical and financial conditions. The paper emphasizes the importance of the discount factor to several decisions made within the sector, including energy conservation. Because of the relevance of the topic to Brazil future, we strongly suggest the utilization of sensitivity analysis techniques. (author)

  16. Incentivizing Decentralized Sanitation: The Role of Discount Rates.

    Science.gov (United States)

    Wood, Alison; Blackhurst, Michael; Garland, Jay L; Lawler, Desmond F

    2016-06-21

    In adoption decisions for decentralized sanitation technologies, two decision makers are involved: the public utility and the individual homeowner. Standard life cycle cost is calculated from the perspective of the utility, which uses a market-based discount rate in these calculations. However, both decision-makers must be considered, including their differing perceptions of the time trade-offs inherent in a stream of costs and benefits. This study uses the discount rate as a proxy for these perceptions and decision-maker preferences. The results in two case studies emphasize the dependence on location of such analyses. Falmouth, Massachusetts, appears to be a good candidate for incentivizing decentralized sanitation while the Allegheny County Sanitary Authority service area in Pennsylvania appears to have no need for similar incentives. This method can be applied to any two-party decision in which the parties are expected to have different discount rates.

  17. Discount rates for social cost benefit analysis of nuclear energy

    International Nuclear Information System (INIS)

    Owen, P.A.

    1978-01-01

    The question that this paper addresses is how decisions affecting many citizens should be made when there are uncertain outcomes in the distant future. By distant is meant beyond the lifetimes of individuals alive now. Thus the proposed methodology would apply to many decisions in nuclear energy from the investment in new energy sources such as fusion, to the long-term storage of wastes. Decisions of this type have usually been analyzed using cost benefit analysis. In this case, future outcomes are discounted at the so-called social discount rate. By comparison, the proposed methodology uses information on individual citizen's preferences and willingness to pay to make a future generation better off. The connection between the proposed approach and more traditional discounting techniques is examined using the government decision about storing helium for the future as an example

  18. Diminished social reward anticipation in the broad autism phenotype as revealed by event-related brain potentials.

    Science.gov (United States)

    Cox, Anthony; Kohls, Gregor; Naples, Adam J; Mukerji, Cora E; Coffman, Marika C; Rutherford, Helena J V; Mayes, Linda C; McPartland, James C

    2015-10-01

    Diminished responsivity to reward incentives is a key contributor to the social-communication problems seen in autism spectrum disorders (ASDs). Social motivation theories suggest that individuals with ASD do not experience social interactions as rewarding, leading to negative consequences for the development of brain circuitry subserving social information. In this study, we examined neural responses to social and non-social reward anticipation in 35 typically developing young adults, examining modulation of reward sensitivity by level of autistic traits. Using an Event-related potential incentive-delay task incorporating novel, more ecologically valid forms of reward, higher expression of autistic traits was associated with an attenuated P3 response to the anticipation of social (simulated real-time video feedback from an observer), but not non-social (candy), rewards. Exploratory analyses revealed that this was unrelated to mentalizing ability. The P3 component reflects motivated attention to reward signals, suggesting attenuated motivation allocation specific to social incentives. The study extends prior findings of atypical reward anticipation in ASD, demonstrating that attenuated social reward responsiveness extends to autistic traits in the range of typical functioning. Results support the development of innovative paradigms for investigating social and non-social reward responsiveness. Insight into vulnerabilities in reward processing is critical for understanding social function in ASD. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Dynamical instabilities in a simple minority game with discounting

    International Nuclear Information System (INIS)

    Challet, D; De Martino, A; Marsili, M

    2008-01-01

    We explore the effect of discounting and experimentation in a simple model of interacting adaptive agents. Agents belong to either of two types and each has to decide whether to participate in a game or not, the game being profitable when there is an excess of players of the other type. We find the emergence of large fluctuations as a result of the onset of a dynamical instability which may arise discontinuously (increasing the discount factor) or continuously (decreasing the experimentation rate). The phase diagram is characterized in detail and noise amplification close to a bifurcation point is identified as the physical mechanism behind the instability. (letter)

  20. Life Insurance and Annuity Demand under Hyperbolic Discounting

    Directory of Open Access Journals (Sweden)

    Siqi Tang

    2018-04-01

    Full Text Available In this paper, we analyse and construct a lifetime utility maximisation model with hyperbolic discounting. Within the model, a number of assumptions are made: complete markets, actuarially fair life insurance/annuity is available, and investors have time-dependent preferences. Time dependent preferences are in contrast to the usual case of constant preferences (exponential discounting. We find: (1 investors (realistically demand more life insurance after retirement (in contrast to the standard model, which showed strong demand for life annuities, and annuities are rarely purchased; (2 optimal consumption paths exhibit a humped shape (which is usually only found in incomplete markets under the assumptions of the standard model.

  1. Effects of pulvinar inactivation on spatial decision-making between equal and asymmetric reward options.

    Science.gov (United States)

    Wilke, Melanie; Kagan, Igor; Andersen, Richard A

    2013-08-01

    The ability to selectively process visual inputs and to decide between multiple movement options in an adaptive manner is critical for survival. Such decisions are known to be influenced by factors such as reward expectation and visual saliency. The dorsal pulvinar connects to a multitude of cortical areas that are involved in visuospatial memory and integrate information about upcoming eye movements with expected reward values. However, it is unclear whether the dorsal pulvinar is critically involved in spatial memory and reward-based oculomotor decision behavior. To examine this, we reversibly inactivated the dorsal portion of the pulvinar while monkeys performed a delayed memory saccade task that included choices between equally or unequally rewarded options. Pulvinar inactivation resulted in a delay of saccade initiation toward memorized contralesional targets but did not affect spatial memory. Furthermore, pulvinar inactivation caused a pronounced choice bias toward the ipsilesional hemifield when the reward value in the two hemifields was equal. However, this choice bias could be alleviated by placing a high reward target into the contralesional hemifield. The bias was less affected by the manipulation of relative visual saliency between the two competing targets. These results suggest that the dorsal pulvinar is involved in determining the behavioral desirability of movement goals while being less critical for spatial memory and reward processing.

  2. Two facets of patience in young children: Waiting with and without an explicit reward.

    Science.gov (United States)

    Barragan-Jason, Gladys; Atance, Cristina; Kopp, Leia; Hopfensitz, Astrid

    2018-07-01

    Patience, or the ability to tolerate delay, is typically studied using delay of gratification (DoG) tasks. However, among other factors (e.g., type of reward), the use of a reward to test patience is affected by an individual's motivation to obtain the reward (e.g., degree of preference for the small vs. large reward). In addition, DoG tasks do not assess the extent to which an individual can wait in the absence of an explicit reward-or what we term "patience as a virtue." Accordingly, the current study used a new measure of patience-the "pure waiting paradigm"-in which 3- to 5-year-old children waited 3 min with nothing to do and with no explicit reward. We then examined the relation between performance on this task (as assessed by children's spontaneous patient behaviors) and performance on two DoG tasks (candy and video rewards). Significant correlations were found between DoG performance and patient behaviors in the pure waiting paradigm, especially when controlling for motivation. These results and methodology show for the first time a direct link between patience as a virtue and DoG performance and also provide new insights about the study of patience in children. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Random reward priming is task-contingent

    DEFF Research Database (Denmark)

    Ásgeirsson, Árni Gunnar; Kristjánsson, Árni

    2014-01-01

    Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings...

  4. Premotor and Motor Cortices Encode Reward.

    Directory of Open Access Journals (Sweden)

    Pavan Ramkumar

    Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.

  5. Developmental delay

    Science.gov (United States)

    Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

  6. A comparison of probability of ruin and expected discounted utility ...

    African Journals Online (AJOL)

    Individuals in defined-contribution retirement funds currently have a number of options as to how to finance their post-retirement spending. The paper considers the ranking of selected annuitisation strategies by the probability of ruin and by expected discounted utility under different scenarios. 'Ruin' is defined as occurring ...

  7. Deriving the Dividend Discount Model in the Intermediate Microeconomics Class

    Science.gov (United States)

    Norman, Stephen; Schlaudraff, Jonathan; White, Karianne; Wills, Douglas

    2013-01-01

    In this article, the authors show that the dividend discount model can be derived using the basic intertemporal consumption model that is introduced in a typical intermediate microeconomics course. This result will be of use to instructors who teach microeconomics to finance students in that it demonstrates the value of utility maximization in…

  8. 24 CFR 201.13 - Interest and discount points.

    Science.gov (United States)

    2010-04-01

    .... Interest on the loan shall accrue from the date of the loan, and shall be calculated on a simple interest... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Interest and discount points. 201... TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.13 Interest and...

  9. MODERN INDICATORS DERIVED FROM VALUE CREATION AND DISCOUNTED

    Directory of Open Access Journals (Sweden)

    Cican Simona

    2013-07-01

    In this article, we will present the connection between discounted cash flow methods and the indicators derived from value creation, based on the business finance theory, which says that firm value will increase if projects with positive net present value are accepted, while it will be destroyed if projects with negative net present value are accepted.

  10. Implicit individual discount rate in China: A contingent valuation study.

    Science.gov (United States)

    Wang, Hua; He, Jie

    2018-03-15

    Two contingent valuation (CV) surveys were conducted in Kunming, China, to estimate households' willingness to pay (WTP) for the Panlong River rehabilitation project. The two surveys were conducted using the same procedures and questionnaires except for the payment schedule arrangements, which permitted a calculation of respondents' implicit discount rate. The surveys provided two estimates of WTP, one with a mean of 23 Yuan in monthly payment over 5 years and the other with a mean of 311 Yuan in a lump-sum payment that will cover all the expenses for a period of 5 years. The results produce an estimate of monthly discount rate of 7.6%-12.6% or annual discount rate of 141-315%. The estimates are higher than that reported from those studies conducted in the U.S., but are compatible with that of some other studies. This study also shows that both mean individual WTP and implicit individual discount rates are closely related to household demographic and economic characteristics and environment-related perceptions, as reported in the studies conducted in other countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Global warming: discounting is not the issue, but substitutability is

    International Nuclear Information System (INIS)

    Neumayer, E.

    1999-01-01

    The cost-benefit study of Nordhaus (1994) is representative for the neoclassical approach towards global warming. Nordhaus found that no substantial emission cuts are warranted. Most of his critics have concentrated on the issue of discounting and demanded that a lower discount rate should be applied. These criticisms first miss the point and second lead to ethically dubious, inconsistent conclusions and inefficient policy choices. They miss the point because the real problem of Nordhaus's methodology is his implicit underlying assumption of perfect substitutability between natural and other forms of capital. Given the validity of this assumption, lowering the rate of discount is inconsistent with current savings behaviour, is ethically dubious because future generations will be much richer than the current one anyway, and is inefficient because scarce financial resources are channelled into emissions abatement that exhibits rates of return far inferior to alternative public investments. Any call for aggressive emission abatement must therefore directly attack the perfect substitutability assumption of neoclassical economics. The real disagreement is about whether consumption growth can compensate for environmental degradation caused by global warming. Discounting is not the issue, but substitutability is. (author)

  12. Market and Impact Study Setting Up MMX Discount Store

    OpenAIRE

    Sabina Irimie; Andreea Ionică; Virginia Băleanu; Cristina Osvath

    2008-01-01

    The paper is focused on the following elements of the impact study’s content: social and economic features of the area and the social, economic and commercial impact. Currently we witness the materialisation of the research’s results by setting up such a store MMX DISCOUNT in the town of Vulcan from the Jiu Valley

  13. Maximizing the model for Discounted Stream of Utility from ...

    African Journals Online (AJOL)

    Osagiede et al. (2009) considered an analytic model for maximizing discounted stream of utility from consumption when the rate of production is linear. A solution was provided to a level where methods of solving order differential equations will be applied, but they left off there, as a result of the mathematical complexity ...

  14. Special discount to the members of the Staff Association

    CERN Multimedia

    Association du personnel

    2012-01-01

    FNAC 5% discount on gifts card available in four Swiss shops without any restriction. Gifts card on sale to the Staff Association Secretariat. TPG 50 CHF discount on annual subscriptions. Subscription « tout Genève » for adult: 650 CHF; for junior: 400 CHF. On sale to the Staff Association Secretariat. Théâtre de Carouge Discount of 5.-CHF for all shows (30.– CHF instead of 35.-CHF) and on season tickets « first performance » ( 132.– CHF instead 162.– CHF) and also on « classical » ( 150.– CHF instead of 180.– CHF) upon presentation of your Staff Association membership card before payment. Aquaparc Discounted prices on admission of whole day. Children from 5 to 15 years: 30.-CHF instead of 39.-CHF; Adults from 16 years: 36.-CHF instead of 49.-CHF. Tickets on sale to the Staff Association Secretariat. Go Sport 15% off on all purchases in the whole shop upon present...

  15. Pension Fund Asset Allocation and Liability Discount Rates

    NARCIS (Netherlands)

    Andonov, Aleksandar; Bauer, Rob; Cremers, Martijn

    2017-01-01

    The unique regulation of U.S. public pension funds links their liability discount rate to the expected return on assets, which gives them incentives to invest more in risky assets in order to report a better funding status. Comparing public and private pension funds in the United States, Canada, and

  16. Reward-related frontostriatal activity and smoking behavior among adolescents in treatment for smoking cessation.

    Science.gov (United States)

    Garrison, Kathleen A; Yip, Sarah W; Balodis, Iris M; Carroll, Kathleen M; Potenza, Marc N; Krishnan-Sarin, Suchitra

    2017-08-01

    Tobacco use is often initiated during adolescence and continued into adulthood despite desires to quit. A better understanding of the neural correlates of abstinence from smoking in adolescents may inform more effective smoking cessation interventions. Neural reward systems are implicated in tobacco use disorder, and adolescent smokers have shown reduced reward-related ventral striatal activation related to increased smoking. The current study evaluated nondrug reward anticipation in adolescent smokers using a monetary incentive delay task in fMRI pre- and post- smoking cessation treatment (n=14). This study tested how changes in neural responses to reward anticipation pre- to post-treatment were related to reduced smoking. An exploratory analysis in a larger sample of adolescents with only pre-treatment fMRI (n=28) evaluated how neural responses to reward anticipation were related to behavioral inhibition and behavioral activation scales. Adolescent smokers showed pre- to post-treatment increases in reward anticipation-related activity in the bilateral nucleus accumbens and insula, and medial prefrontal cortex, and greater increases in reward anticipation-related activity were correlated with larger percent days of smoking abstinence during treatment. These findings suggest that reduced smoking during smoking cessation treatment is associated with a "recovery of function" in frontostriatal responses to nondrug reward anticipation in adolescent smokers, although comparison with a developmental control group of adolescent nonsmokers is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Reward anticipation modulates the effect of stress-related increases in cortisol on episodic memory.

    Science.gov (United States)

    Quent, Jörn A; McCullough, Andrew M; Sazma, Matt; Wolf, Oliver T; Yonelinas, Andrew P

    2018-01-01

    When acute stress is experienced shortly after an event is encoded into memory, this can slow the forgetting of the study event, which is thought to reflect the effect of cortisol on consolidation. In addition, when events are encoded under conditions of high reward they tend to be remembered better than those encoded under non-rewarding conditions, and these effects are thought to reflect the operation of the dopaminergic reward system. Although both modulatory systems are believed to impact the medial temporal lobe regions critical for episodic memory, the manner, and even the extent, to which these two systems interact is currently unknown. To address this question in the current study, participants encoded words under reward or non-reward conditions, then one half of the participants were stressed using the social evaluation cold pressor task and the other half completed a non-stress control task. After a two-hour delay, all participants received a free recall and recognition memory test. There were no significant effects of stress or reward on overall memory performance. However, for the non-reward items, increases in stress-related cortisol in stressed participants were related to increases in recall and increases in recollection-based recognition responses. In contrast, for the reward items, increases in stress-related cortisol were not related to increases in memory performance. The results indicate that the stress and the reward systems interact in the way they impact episodic memory. The results are consistent with tag and capture models in the sense that cortisol reactivity can only affect non-reward items because plasticity-related products are already provided by reward anticipation. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Tariff-Mediated Network Effects versus Strategic Discounting: Evidence from German Mobile Telecommunications

    OpenAIRE

    Zucchini, Leon; Claussen, Jörg; Trüg, Moritz

    2013-01-01

    Mobile telecommunication operators routinely charge subscribers lower prices for calls on their own network than for calls to other networks (on-net discounts). Studies on tariff-mediated network effects suggest this is due to large operators using on-net discounts to damage smaller rivals. Alternatively, research on strategic discounting suggests small operators use on-net discounts to advertise with low on-net prices. We test the relative strength of these effects using data on tariff setti...

  19. Impaired reward learning and intact motivation after serotonin depletion in rats.

    Science.gov (United States)

    Izquierdo, Alicia; Carlos, Kathleen; Ostrander, Serena; Rodriguez, Danilo; McCall-Craddolph, Aaron; Yagnik, Gargey; Zhou, Feimeng

    2012-08-01

    Aside from the well-known influence of serotonin (5-hydroxytryptamine, 5-HT) on emotional regulation, more recent investigations have revealed the importance of this monoamine in modulating cognition. Parachlorophenylalanine (PCPA) depletes 5-HT by inhibiting tryptophan hydroxylase, the enzyme required for 5-HT synthesis and, if administered at sufficiently high doses, can result in a depletion of at least 90% of the brain's 5-HT levels. The present study assessed the long-lasting effects of widespread 5-HT depletions on two tasks of cognitive flexibility in Long Evans rats: effort discounting and reversal learning. We assessed performance on these tasks after administration of either 250 or 500 mg/kg PCPA or saline (SAL) on two consecutive days. Consistent with a previous report investigating the role of 5-HT on effort discounting, pretreatment with either dose of PCPA resulted in normal effortful choice: All rats continued to climb tall barriers to obtain large rewards and were not work-averse. Additionally, rats receiving the lower dose of PCPA displayed normal reversal learning. However, despite intact motivation to work for food rewards, rats receiving the largest dose of PCPA were unexpectedly impaired relative to SAL rats on the pretraining stages leading up to reversal learning, ultimately failing to approach and respond to the stimuli associated with reward. High performance liquid chromatography (HPLC) with electrochemical detection confirmed 5-HT, and not dopamine, levels in the ventromedial frontal cortex were correlated with this measure of associative reward learning. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. The role of the striatum in effort-based decision-making in the absence of reward.

    Science.gov (United States)

    Schouppe, Nathalie; Demanet, Jelle; Boehler, Carsten N; Ridderinkhof, K Richard; Notebaert, Wim

    2014-02-05

    Decision-making involves weighing costs against benefits, for instance, in terms of the effort it takes to obtain a reward of a given magnitude. This evaluation process has been linked to the dorsal anterior cingulate cortex (dACC) and the striatum, with activation in these brain structures reflecting the discounting effect of effort on reward. Here, we investigate how cognitive effort influences neural choice processes in the absence of an extrinsic reward. Using functional magnetic resonance imaging in humans, we used an effort-based decision-making task in which participants were required to choose between two options for a subsequent flanker task that differed in the amount of cognitive effort. Cognitive effort was manipulated by varying the proportion of incongruent trials associated with each choice option. Choice-locked activation in the striatum was higher when participants chose voluntarily for the more effortful alternative but displayed the opposite trend on forced-choice trials. The dACC revealed a similar, yet only trend-level significant, activation pattern. Our results imply that activation levels in the striatum reflect a cost-benefit analysis, in which a balance is made between effort discounting and the intrinsic motivation to choose a cognitively challenging task. Moreover, our findings indicate that it matters whether this challenge is voluntarily chosen or externally imposed. As such, the present findings contrast with classical findings on effort discounting that found reductions in striatum activation for higher effort by finding enhancements of the same neural circuits when a cognitively challenging task is voluntarily selected and does not entail the danger of losing reward.

  1. 78 FR 67393 - Change in Discount Rate for Water Resources Planning

    Science.gov (United States)

    2013-11-12

    ... Discount Rate for Water Resources Planning AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of change. SUMMARY: The Water Resources Planning Act of 1965 and the Water Resources Development Act of 1974 require an annual determination of a discount rate for Federal water resources planning. The discount rate...

  2. On the Relation between Discounting of Climate Change and Edgeworth-Pareto Substitutability

    NARCIS (Netherlands)

    Kögel, M.T.

    2009-01-01

    To justify substantial carbon emission reductions, recent literature on cost-benefit analysis of climate change suggests discounting environmental quality at a lower discount rate than the standard consumption discount rate. Recent literature also shows that a theoretical foundation for such a lower

  3. 31 CFR 356.21 - How are awards at the high yield or discount rate calculated?

    Science.gov (United States)

    2010-07-01

    ... discount rate calculated? 356.21 Section 356.21 Money and Finance: Treasury Regulations Relating to Money... high yield or discount rate calculated? (a) Awards to submitters. We generally prorate bids at the highest accepted yield or discount rate under § 356.20(a)(2) of this part. For example, if 80.15% is the...

  4. Cash Flow and Discount Rate Risk in Up and Down Markets: What is actually priced?

    NARCIS (Netherlands)

    Botshekan, M.; Kraeussl, R.G.W.; Lucas, A.

    2012-01-01

    We test whether asymmetric preferences for losses versus gains affect the prices of cash flow versus discount rate risk. We construct a return decomposition distinguishing cash flow and discount rate betas in up and down markets. Using U.S. data, we find that downside cash flow and discount rate

  5. Evolutionary advantages of adaptive rewarding

    International Nuclear Information System (INIS)

    Szolnoki, Attila; Perc, Matjaž

    2012-01-01

    Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. (paper)

  6. Usability testing for the rest of us: the application of discount usability principles in the development of an online communications assessment application.

    Science.gov (United States)

    Brock, Douglas; Kim, Sara; Palmer, Odawni; Gallagher, Thomas; Holmboe, Eric

    2013-01-01

    Usability evaluation provides developers and educators with the means to understand user needs, improve overall product utility, and increase user satisfaction. The application of "discount usability" principles developed to make usability testing more practical and useful may improve user experience at minimal cost and require little existing expertise to conduct. We describe an application of discount usability to a high-fidelity online communications assessment application developed by the University of Washington for the American Board of Internal Medicine. Eight internal medicine physicians completed a discount usability test. Sessions were recorded and the videos analyzed for significant usability concerns. Concerns were identified, summarized, discussed, and prioritized by the authors in collaboration with the software developers before implementing any changes to the interface. Thirty-eight significant usability issues were detected and four technical problems were identified. Each issue was responded to through modification of the software, by providing additional instruction, or delayed for a later version to be developed. Discount usability can be easily implemented in academic developmental activities. Our study resulted in the discovery and remediation of significant user problems, in addition to giving important insight into the novel methods built into the application.

  7. The Social Rewards of Engagement

    DEFF Research Database (Denmark)

    Robison, Joshua

    2017-01-01

    Political interest is a crucial precursor to political engagement, but little is known about how to stimulate greater interest. The article explores the role social motives have in generating interest. A laboratory experiment is used in which it is possible to manipulate beliefs about the social...... rewards of political engagement as well as external efficacy beliefs. Across two types of measures for political interest (self-reports and revealed preferences), connecting political engagement with social rewards led to substantial increases in political interest. Moreover, these effects were...... particularly strong among individuals with low levels of external efficacy. Ultimately, the data provide clear evidence that political interest can be positively stimulated with social rewards mobilisation techniques and that it is rooted in beliefs about the potential motives pursuable through politics...

  8. Retailer's inventory system in a two-level trade credit financing with selling price discount and partial order cancelations

    Science.gov (United States)

    Thangam, A.

    2015-06-01

    In today's fast marketing over the Internet or online, many retailers want to trade at the same time and change their marketing strategy to attract more customers. Some of the customers may decide to cancel their orders partially with a retailer due to various reasons such as increase in customer's waiting time, loss of customer's goodwill on retailer's business, attractive promotional schemes offered by other retailers etc. Even though there is a lag in trading and order cancelation, this paper attempts to develop the retailer's inventory model with the effect of order cancelations during advance sales period. The retailer announces a price discount program during advance sales period to promote his sales and also he offers trade credit financing during the sales periods. The retailer availing trade credit period from his supplier offers a permissible delay period to his customers. The customer who gets an item has allowed paying on or before the permissible delay period which is accounted from the buying time rather than the start period of inventory sales. This accounts for significant changes in the calculations of interest payable and interest earned by the retailer. The retailer's total cost is minimized so as to find out the optimal replenishment cycle time and price discount policies through a solution procedure. The results derived in mathematical theorems are implemented in numerical examples and sensitivity analyses on several inventory parameters are obtained.

  9. Retailer's inventory system in a two-level trade credit financing with selling price discount and partial order cancellations

    Science.gov (United States)

    Thangam, A.

    2014-02-01

    In today's fast marketing over the Internet or online, many retailers want to trade at the same time and change their marketing strategy to attract more customers. Some of the customers may decide to cancel their orders partially with a retailer due to various reasons such as increase in customer's waiting time, loss of customer's goodwill on retailer's business, and attractive promotional schemes offered by other retailers. Even though there is a lag in trading and order cancellation, this paper attempts to develop the retailer's inventory model with the effect of order cancellations during advance sales period. The retailer announces a price discount program during advance sales period to promote his sales and also offers trade credit financing during the sales periods. The retailer availing trade credit period from his supplier offers a permissible delay period to his customers. The customer who gets an item is allowed to pay on or before the permissible delay period which is accounted from the buying time rather than from the start period of inventory sales. This accounts for significant changes in the calculations of interest payable and interest earned by the retailer. The retailer's total cost is minimized so as to find out the optimal replenishment cycle time and price discount policies through a solution procedure. The results derived in mathematical theorems are implemented in numerical examples, and sensitivity analyses on several inventory parameters are obtained.

  10. Benefit assessment in Germany: implications for price discounts.

    Science.gov (United States)

    Theidel, Ulrike; von der Schulenburg, J-Matthias Graf

    2016-12-01

    The AMNOG regulation, introduced in 2011 in Germany, changed the game for new drugs. Now, the industry is required to submit a dossier to the GBA (the central decision body in the German sickness fund system) to show additional benefit. After granting the magnitude of the additional benefit by the GBA, the manufacturer is entitled to negotiate the reimbursement price with the GKV-SV (National Association of Statutory Health Insurance Funds). The reimbursement price is defined as a discount on the drug price at launch. As the price or discount negotiations between the manufacturers and the GKV-SV takes place behind closed doors, the factors influencing the results of the negotiation are not known. The aim of this evaluation is to identify factors influencing the results of the AMNOG price negotiation process. The analysis was based on a dataset containing detailed information on all assessments until the end of 2015. A descriptive analysis was followed by an econometric analysis of various potential factors (benefit rating, size of target population, deviating from appropriate comparative therapy and incorporation of HRQoL-data). Until December 2015, manufacturers and the GKV-SV finalized 96 negotiations in 193 therapeutic areas, based on assessment conducted by the GBA. The GBA has granted an additional benefit to 100/193 drug innovations. Negotiated discount was significantly higher for those drugs without additional benefit (p = 0.030) and non-orphan drugs (p = 0.015). Smaller population size, no deviation from recommended appropriate comparative therapy and the incorporation of HRQoL-data were associated with a lower discount on the price at launch. However, neither a uni- nor the multivariate linear regression showed enough power to predict the final discount. Although the AMNOG regulation implemented binding and strict rules for the benefit assessment itself, the outcome of the discount negotiations are still unpredictable. Obviously, negotiation

  11. Competitor suppresses neuronal representation of food reward in the nucleus accumbens/medial striatum of domestic chicks.

    Science.gov (United States)

    Amita, Hidetoshi; Matsushima, Toshiya

    2014-07-15

    To investigate the role of social contexts in controlling the neuronal representation of food reward, we recorded single neuron activity in the medial striatum/nucleus accumbens of domestic chicks and examined whether activities differed between two blocks with different contexts. Chicks were trained in an operant task to associate light-emitting diode color cues with three trial types that differed in the type of food reward: no reward (S-), a small reward/short-delay option (SS), and a large reward/long-delay alternative (LL). Amount and duration of reward were set such that both of SS and LL were chosen roughly equally. Neurons showing distinct cue-period activity in rewarding trials (SS and LL) were identified during an isolation block, and activity patterns were compared with those recorded from the same neuron during a subsequent pseudo-competition block in which another chick was allowed to forage in the same area, but was separated by a transparent window. In some neurons, cue-period activity was lower in the pseudo-competition block, and the difference was not ascribed to the number of repeated trials. Comparison at neuronal population level revealed statistically significant suppression in the pseudo-competition block in both SS and LL trials, suggesting that perceived competition generally suppressed the representation of cue-associated food reward. The delay- and reward-period activities, however, did not significantly different between blocks. These results demonstrate that visual perception of a competitive forager per se weakens the neuronal representation of predicted food reward. Possible functional links to impulse control are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Involvement of cannabinoid system in the nucleus accumbens on delay-based decision making in the rat.

    Science.gov (United States)

    Fatahi, Zahra; Sadeghi, Bahman; Haghparast, Abbas

    2018-01-30

    The nucleus accumbens (NAc) plays a fundamental role in decision making and anticipation of reward. In addition, exogenous cannabinoids affect the behavior of humans and animals including disruption of short-term memory and cognitive impairments. Therefore, in this study, cannabinoid agonist and antagonist were administrated into the NAc to determine the effect of cannabinoid activation in the entire NAc on delay-based decision making. Rats were trained on a cost-benefit T-maze decision making task in which the animals were well-trained to choose between a small/immediate reward and a large/delay reward. After training, the animals were implanted with guide cannulae in the NAc. On test day, they received cannabinoid agonist (Win 55,212-2; 10, 50 and 100μM) and/or antagonist (AM251; 45μM) into the NAc. Percentage of high reward choice and latency of reward achievement were evaluated. Results showed that cannabinoid agonist administration caused a decrease in high reward choice such that rats selected small/immediate reward instead of large/delay reward. Moreover, in agonist-treated animals latency of reward achievement increased. Effects of cannabinoid activation on delay-based decision making with equivalent delays demonstrated that if the delay was equated on both arm goals, animals still had a preference for the high/delay reward, showing the results was not caused by an impairment of spatial preference or memory. These finding clarified that cannabinoid system activation in the entire NAc plays a critical role in the regulation of delay-based decision making. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Introduction: Addiction and Brain Reward and Anti-Reward Pathways

    Science.gov (United States)

    Gardner, Eliot L.

    2013-01-01

    Addictive drugs have in common that they are voluntarily self-administered by laboratory animals (usually avidly) and that they enhance the functioning of the reward circuitry of the brain (producing the “high” that the drug-user seeks). The core reward circuitry consists of an “in series” circuit linking the ventral tegmental area, nucleus accumbens, and ventral pallidum - via the medial forebrain bundle. Although originally believed to encode simply the set-point of hedonic tone, these circuits are now believed to be functionally far more complex - also encoding attention, expectancy of reward, disconfirmation of reward expectancy, and incentive motivation. “Hedonic dysregulation” within these circuits may lead to addiction. The “second-stage” dopaminergic component in this reward circuitry is the crucial addictive-drug-sensitive component. All addictive drugs have in common that they enhance (directly or indirectly or even transsynaptically) dopaminergic reward synaptic function in the nucleus accumbens. Drug self-administration is regulated by nucleus accumbens dopamine levels, and is done to keep nucleus accumbens dopamine within a specific elevated range (to maintain a desired hedonic level). For some classes of addictive drugs (e.g., opiates), tolerance to the euphoric effects develops with chronic use. Post-use dysphoria then comes to dominate reward circuit hedonic tone, and addicts no longer use drugs to get “high,” but simply to get back to normal (“get straight”). The brain circuits mediating the pleasurable effects of addictive drugs are anatomically, neurophysiologically, and neurochemically different from those mediating physical dependence, and from those mediating craving and relapse. There are important genetic variations in vulnerability to drug addiction, yet environmental factors such as stress and social defeat also alter brain-reward mechanisms in such a manner as to impart vulnerability to addiction. In short, the

  14. Neural alterations of fronto-striatal circuitry during reward anticipation in euthymic bipolar disorder.

    Science.gov (United States)

    Schreiter, S; Spengler, S; Willert, A; Mohnke, S; Herold, D; Erk, S; Romanczuk-Seiferth, N; Quinlivan, E; Hindi-Attar, C; Banzhaf, C; Wackerhagen, C; Romund, L; Garbusow, M; Stamm, T; Heinz, A; Walter, H; Bermpohl, F

    2016-11-01

    Bipolar disorder (BD), with the hallmark symptoms of elevated and depressed mood, is thought to be characterized by underlying alterations in reward-processing networks. However, to date the neural circuitry underlying abnormal responses during reward processing in BD remains largely unexplored. The aim of this study was to investigate whether euthymic BD is characterized by aberrant ventral striatal (VS) activation patterns and altered connectivity with the prefrontal cortex in response to monetary gains and losses. During functional magnetic resonance imaging 20 euthymic BD patients and 20 age-, gender- and intelligence quotient-matched healthy controls completed a monetary incentive delay paradigm, to examine neural processing of reward and loss anticipation. A priori defined regions of interest (ROIs) included the VS and the anterior prefrontal cortex (aPFC). Psychophysiological interactions (PPIs) between these ROIs were estimated and tested for group differences for reward and loss anticipation separately. BD participants, relative to healthy controls, displayed decreased activation selectively in the left and right VS during anticipation of reward, but not during loss anticipation. PPI analyses showed decreased functional connectivity between the left VS and aPFC in BD patients compared with healthy controls during reward anticipation. This is the first study showing decreased VS activity and aberrant connectivity in the reward-processing circuitry in euthymic, medicated BD patients during reward anticipation. Our findings contrast with research supporting a reward hypersensitivity model of BD, and add to the body of literature suggesting that blunted activation of reward processing circuits may be a vulnerability factor for mood disorders.

  15. Excessive body fat linked to blunted somatosensory cortex response to general reward in adolescents.

    Science.gov (United States)

    Navas, J F; Barrós-Loscertales, A; Costumero-Ramos, V; Verdejo-Román, J; Vilar-López, R; Verdejo-García, A

    2018-01-01

    The brain reward system is key to understanding adolescent obesity in the current obesogenic environment, rich in highly appetising stimuli, to which adolescents are particularly sensitive. We aimed to examine the association between body fat levels and brain reward system responsivity to general (monetary) rewards in male and female adolescents. Sixty-eight adolescents (34 females; mean age (s.d.)= 16.56 (1.35)) were measured for body fat levels with bioelectric impedance, and underwent a functional magnetic resonance imaging (fMRI) scan during the Monetary Incentive Delay (MID) task. The MID task reliably elicits brain activations associated with two fundamental aspects of reward processing: anticipation and feedback. We conducted regression analyses to examine the association between body fat and brain reward system responsivity during reward anticipation and feedback, while controlling for sex, age and socioeconomic status. We also analysed the moderating impact of sex on the relationship between fat levels and brain responsivity measures. Brain imaging analyses were corrected for multiple comparisons, with a cluster-defining threshold of Preward feedback after controlling for key sociodemographic variables. Although we did not find significant associations between body fat and brain activations during reward anticipation, S1/supramarginal gyrus activation during feedback was linked to increased negative prediction error, that is, less reward than expected, in illustrative post hoc analyses. Sex did not significantly moderate the association between body fat and brain activation in the MID task. In adolescents, higher adiposity is linked to hypo-responsivity of somatosensory regions during general (monetary) reward feedback. Findings suggest that adolescents with excess weight have blunted activation in somatosensory regions involved in reward feedback learning.

  16. Individual discount rates and smoking: evidence from a field experiment in Denmark.

    Science.gov (United States)

    Harrison, Glenn W; Lau, Morten I; Rutström, E Elisabet

    2010-09-01

    We elicit measures of individual discount rates from a representative sample of the Danish population and test two substantive hypotheses. The first hypothesis is that smokers have higher individual discount rates than non-smokers. The second hypothesis is that smokers are more likely to have time inconsistent preferences than non-smokers, where time inconsistency is indicated by a hyperbolic discounting function. We control for the concavity of the utility function in our estimates of individual discount rates and find that male smokers have significantly higher discount rates than male non-smokers. However, smoking has no significant association with discount rates among women. This result is robust across exponential and hyperbolic discounting functions. We consider the sensitivity of our conclusions to a statistical specification that allows each observation to potentially be generated by more than one latent data-generating process. Copyright 2010 Elsevier B.V. All rights reserved.

  17. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    . The underlying reasons for the large variation in the age at pubertal onset are not fully established; however, nutritional status and socioeconomic and environmental factors are known to be influencing, and a significant amount of influencing genetic factors have also been identified. The challenges...... optimal in discriminating especially CDGP from HH. Management of the delayed puberty depends on the etiology. For boys with CDGP an observational period will often reveal imminent puberty. If puberty is not progressing spontaneously, sex steroid replacement is effective in stimulating the development...

  18. Working Memory Load Strengthens Reward Prediction Errors.

    Science.gov (United States)

    Collins, Anne G E; Ciullo, Brittany; Frank, Michael J; Badre, David

    2017-04-19

    Reinforcement learning (RL) in simple instrumental tasks is usually modeled as a monolithic process in which reward prediction errors (RPEs) are used to update expected values of choice options. This modeling ignores the different contributions of different memory and decision-making systems thought to contribute even to simple learning. In an fMRI experiment, we investigated how working memory (WM) and incremental RL processes interact to guide human learning. WM load was manipulated by varying the number of stimuli to be learned across blocks. Behavioral results and computational modeling confirmed that learning was best explained as a mixture of two mechanisms: a fast, capacity-limited, and delay-sensitive WM process together with slower RL. Model-based analysis of fMRI data showed that striatum and lateral prefrontal cortex were sensitive to RPE, as shown previously, but, critically, these signals were reduced when the learning problem was within capacity of WM. The degree of this neural interaction related to individual differences in the use of WM to guide behavioral learning. These results indicate that the two systems do not process information independently, but rather interact during learning. SIGNIFICANCE STATEMENT Reinforcement learning (RL) theory has been remarkably productive at improving our understanding of instrumental learning as well as dopaminergic and striatal network function across many mammalian species. However, this neural network is only one contributor to human learning and other mechanisms such as prefrontal cortex working memory also play a key role. Our results also show that these other players interact with the dopaminergic RL system, interfering with its key computation of reward prediction errors. Copyright © 2017 the authors 0270-6474/17/374332-11$15.00/0.

  19. Social interaction anxiety and the discounting of positive interpersonal events.

    Science.gov (United States)

    Vassilopoulos, Stephanos P; Banerjee, Robin

    2010-10-01

    Recent research has indicated that individuals with social interaction anxiety make biased interpretations of positive social interactions, with greater general apprehension in response to such events and more negative predictions about the future. There has also been some preliminary evidence for a second facet of interpretation bias, namely a failure to accept others' positive reactions at face value, but this has so far not been adequately studied. The present study developed a new measure of this "discounting" dimension and utilized a nonclinical sample of undergraduate students to provide an initial analysis of the scale. Results provide early support for the psychometric properties of our scale, and indicate that discounting mediates the relationship between social interaction anxiety and low positive affect, over and above the previously studied aspect of positive event interpretation bias. The implications for treatment interventions and further research are discussed.

  20. Three residual income valuation methods and discounted cash flow valuation

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    In this paper we show that the three residual Income models for equity valuation always yield the same value as the Discounted Cash Flow Valuation models. We use three residual income measures: Economic Profit, Economic Value Added (EVA) and Cash Value Added. We also show that economic profit and EVA are different, although Copeland, Koller and Murrin (2000, page 55) say that economic profit is a synonym of EVA. Specifically, we first show that the present value of the Economic Profit discoun...