Rates Of Delay Discounting Research Articles

Delay Discounting of Reward and Impulsivity in Eating Disorders: From Anorexia Nervosa to Binge Eating Disorder.

Evidence points to eating disorder patients displaying altered rates of delay discounting (one's degree of preference for immediate rewards over larger delayed rewards). Anorexia nervosa (AN) patients are believed to have an increased capacity to delay reward, which reflects their ability to override the drive to eat. Contrarily, binge eating disorder (BED) patients are associated with a reduced predisposition to delay gratification. Here, we investigated monetary delay discounting and impulsivity in 80 adult women with EDs (56 AN and 24 BED), diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, and 80 healthy controls. AN-restrictive (AN-R) subtype patients showed less steep discounting rates than BED and AN-bingeing/purging subtype patients. Compared with healthy controls and AN-R patients, BED and AN-bingeing/purging patients presented higher delay discounting and positive and negative urgency levels. Our findings suggest that restriction in AN-R patients is associated with disproportionate self-control, whereas bingeing behaviours could be more driven by emotional states and impulsivity traits. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

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

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.

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

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 air quality and health. These results implicate a major public health concern and potential barriers to individual and societal behavior that reduce pollution and emissions for conservation of clean air.

IMPULZIVITA ROMŮ A ČECHŮ A JEJÍ PSYCHOLOGICKÉ, DEMOGRAFICKÉ A SOCIOEKONOMICKÉ KORELÁTY

The article examines the differences in individual discount rates among the Roma ethnic group (Gypsies) and the Czech ethnic group. Low income, low education, and currently unemployed participants (Roma N=27, Czechs N=23) were subjected to pilot experiments based on in-depth questionnaires. In addition to impulsivity (delay-discount rates), the correlation with cognitive aptitude, risk attitudes, and various socioeconomic and demographic characteristics were analysed. Even though the Roma group was characterised by lower cognitive abilities, education, and financial literacy, our results indicate that participants from both groups appear to be equally impatient, with discount rates close to the values of individuals dependent on addictive substances (according to the results of some earlier foreign studies). Nevertheless, the Roma ethnic group is better characterised by inconsistent discounting compared to the Czechs who behave more consistently. However, these results are not robust to alternative estimation characteristics. We also found a positive effect of financial literacy on savings in the Roma sample. The conclusion discusses the influence of the environmental context on impulsivity and reviews the limitations of the study.

The association between parental history and delay discounting among individuals in recovery from addiction

BackgroundFamily history of addiction is a risk factor for substance use disorders. Delay discounting (DD) is associated with the risk of substance use and dependence, and is predictive of the likelihood of successful abstinence and treatment outcomes; thus, we investigated the extent to which having parents with addiction (parental history of addiction) and number of addicted parents affect DD among individuals in recovery from addiction. MethodsData from 177 individuals in recovery from addiction from The International Quit and Recovery Registry (IQRR), an ongoing online data collection program that aims to understand addiction and how people succeed in recovery, were included in the analysis. Participants with no, one, or two parents with addiction were compared on measures of DD using an adjusting-amount task. ResultsParental history of addiction was significantly associated with delay discounting. After controlling for age and gender, which were significantly different between groups, participants reporting two biological parents with addiction had significantly higher DD rates compared to those reporting one or no parents with addiction. ConclusionsParticipants with two parents with addiction had significantly higher rates of discounting compared to those with no or only one parent with addiction. This information can serve as a foundation to better identify and target important subgroups that need additional or non-traditional intervention strategies to address their larger degree of impulsivity and help maintain abstinence or achieve better treatment outcomes.

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

Abstract 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.

Predictors of smoking lapse during a 48-hour laboratory analogue smoking cessation attempt.

Many individuals who attempt to quit smoking experience a smoking lapse early on in the quitting process, with most lapses resulting in a return to regular smoking. Using a novel laboratory model, this study sought to investigate baseline predictors of smoking lapse during a brief, simulated smoking quit attempt. Self-report baseline measures were completed by 81 smokers, who also smoked a cigarette in the laboratory to equate recent smoke exposure. Participants were then given brief face-to-face smoking-cessation counseling along with monetary incentives to abstain from smoking for 48 hr (i.e., $40). Participants returned to the laboratory after 24 hr and 48 hr for assessment of smoking behavior. By 48 hr, 25 participants lapsed, with rates equivalent among men and women (31% vs. 31%). Higher rates of delay discounting and a preference for menthol cigarettes significantly predicted greater odds of lapsing. Shorter time to first cigarette after waking (TTFC) was associated with greater lapse risk at trend levels. No effects were observed for demographic variables, cigarettes per day, prequit abstinence self-efficacy, or depressive symptoms. Future research examining predictors of early lapse and underlying mechanisms is needed, and laboratory analogue models offer a controlled time- and cost-effective framework in which to investigate smoking cessation processes. (PsycINFO Database Record

Smokers’ Elevated Rates of Delay Discounting are Independent of Differences in Primary Personality Dimensions

Although smokers have higher rates of delay discounting, the extent to which this depends on smoking habit and nicotine use is unclear. Because personality factors are correlated with both delay discounting and smoking, we assessed the extent to which the effect size for smoking and delay discounting was attenuated by using the primary dimensions of personality in Eysenck’s system – extraversion, neuroticism, and psychoticism – as covariates. Smokers (n = 367) and non-smokers (n = 421) completed the Eysenck Personality Questionnaire-Revised (EPQ-R) and the Monetary Choice Questionnaire (MCQ) to measure delay discounting. Smokers had higher rates of delay discounting (d = .315). Although extraversion and psychoticism scores were higher for smokers than non-smokers, and were positively correlated with delay discounting, the effect size for smokers decreased only marginally when personality variables were used as covariates (d = .295). A stepwise regression analysis identified 7 EPQ-R items that best predicted delay discounting (R = .281); controlling for a subscale based on these items only reduced the effect size to d = .252, and among the smokers, nicotine dependence remained a significant predictor of delay discounting. Overall results indicate that smokers’ elevated delay discounting is independent of primary personality dimensions, and although correlational, are most consistent with the view that smoking habit and nicotine dependence are causally linked to changes in impulsive decision making.

The Effects of Social Status and Culture on Delay Discounting

AbstractPeople generally tend to discount future outcomes in favor of smaller but immediate gains (i.e., delay discounting). This study examines the hypothesis that culture and social status moderate this tendency, as well as the alternative hypothesis that social status and culture influence delay discounting independently of each other. American and Japanese adults were asked to choose receiving hypothetical monetary rewards either immediately or receiving rewards of different amounts with a delay of 1 year. The results replicated previous findings and supported the alternative hypothesis. Delay discounting was lower when subjective socioeconomic status (i.e., an individual’s perception of her or his social rank) was higher. Also, the Japanese were less likely to discount future rewards than the Americans. However, there was no interaction between social status and culture in influencing the rates of delay discounting.

Testing the construct validity of the Discounting Inventory – Psychometric properties of a Polish and German samples

Abstract The Discounting Inventory (DI), originally developed in polish language, allows the measurement of individual differences in the delay, probabilistic, effort, and social discounting rates. The present study attempted to validate the DI’s psychometric properties using German university students and to compare the results to those from a sample of Polish university students. Over four hundred participants completed the DI and traditional discounting measures. A confirmatory factor analyses indicated that the original four-factor model of the DI provided an excellent fit for the German data and internal consistency was high. These outcomes were similar, if not superior, to those from the Polish sample. DI scores strongly correlated with traditional discounting measures scores in both samples, replicating previous results. These findings indicate that the DI is a valid measure for use in a sample from another cultural setting, which is potentially useful to both researchers and practitioners.

Neural Systems Underlying Individual Differences in Intertemporal Decision-making.

Excessively choosing immediate over larger future rewards, or delay discounting (DD), associates with multiple clinical conditions. Individual differences in DD likely depend on variations in the activation of and functional interactions between networks, representing possible endophenotypes for associated disorders, including alcohol use disorders (AUDs). Numerous fMRI studies have probed the neural bases of DD, but investigations of large-scale networks remain scant. We addressed this gap by testing whether activation within large-scale networks during Now/Later decision-making predicts individual differences in DD. To do so, we scanned 95 social drinkers (18-40 years old; 50 women) using fMRI during hypothetical choices between small monetary amounts available "today" or larger amounts available later. We identified neural networks engaged during Now/Later choice using independent component analysis and tested the relationship between component activation and degree of DD. The activity of two components during Now/Later choice correlated with individual DD rates: A temporal lobe network positively correlated with DD, whereas a frontoparietal-striatal network negatively correlated with DD. Activation differences between these networks predicted individual differences in DD, and their negative correlation during Now/Later choice suggests functional competition. A generalized psychophysiological interactions analysis confirmed a decrease in their functional connectivity during decision-making. The functional connectivity of these two networks negatively correlates with alcohol-related harm, potentially implicating these networks in AUDs. These findings provide novel insight into the neural underpinnings of individual differences in impulsive decision-making with potential implications for addiction and related disorders in which impulsivity is a defining feature.

Maintained Physical Activity Induced Changes in Delay Discounting.

Those who discount the subjective value of delayed rewards less steeply are more likely to engage in physical activity. There is limited research, however, showing whether physical activity can change rates of delay discounting. In a two-experiment series, treatment and maintenance effects of a novel, effort-paced physical activity intervention on delay discounting were evaluated with multiple baseline designs. Using a lap-based method, participants were instructed to exercise at individualized high and low effort levels and to track their own perceived effort. The results suggest that treatment-induced changes in discounting were maintained at follow-up for 13 of 16 participants. In Experiment 2, there were statistically significant group-level improvements in physical activity and delay discounting when comparing baseline with both treatment and maintenance phases. Percentage change in delay discounting was significantly correlated with session attendance and relative pace (min/mile) improvement over the course of the 7-week treatment. Implications for future research are discussed.

Glucose-specific signaling effects on delay discounting in intertemporal choice

We propose that decisions related to resource management (e.g., intertemporal choice between a smaller-and-sooner reward and a larger-and-later reward) are sensitive to and regulated by fluctuating blood glucose levels. Circulating glucose affects intertemporal choice by means of signaling body energy condition instead of serving as a replenishing resource for effortful cognitive processing. We intend to dissociate calorie-supplying functions from glucose-unique anticipatory effects on behavioral resource management, measured by delay discounting in making intertemporal choices. Regarding the anticipatory functions of the glucose–insulin system in regulating the degree of delay discounting, we tested three predictions: First, we predict that the signaling effects of circulating glucose on delay discounting do not need to be dose-dependent as long as glucose fluctuation indicates a directional trend in body energy budget. Second, such effects of glucose fluctuation on delay discounting are phagic (appetite related) instead of dipsian (thirst related). Third, this glucose–insulin signaling system requires glucose as the specific input, thus is insensitive to other forms of sugar that are not insulin regulated. In Study 1, fasting participants were randomly assigned to one of five groups: water consumption, zero-consumption, and three glucose consumption (18g, 36g, and 72g cane sugar/250ml water) groups. The participants competed two sets of intertemporal choice questions with varying delay discounting rates before and after a beverage intervention. The results showed that the rate of delay discounting was negatively correlated to blood glucose levels. The effects of circulating glucose on delay discounting closely followed the changes in blood glucose levels showing a plateau on both dose-response curves (i.e., the sugar dose-blood glucose level curve and the sugar does-delay discounting curve). Secondly, the effects of circulating glucose on delay discounting were significant only in the glucose ingestion group, but not in the zero consumption and the water consumption groups, suggesting that the behavioral effects were in fact related to hunger-reduction instead of thirst-reduction. Study 2 revealed that glucose ingestion, but not water or another form of sugar (xylitol matched to glucose either for sweetness or for calories), reduced delay discounting, making future options more attractive. This result suggests that signaling of body energy budget is indeed glucose-unique. Our results suggest a forecasting mechanism of the glucose-insulin system for both metabolic and behavioral regulations of resource acquisition and allocation.

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

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.

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

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.

Automating Scoring of Delay Discounting for the 21- and 27-Item Monetary Choice Questionnaires.

Delay discounting describes the process wherein rewards lose value as a function of their delayed receipt; how quickly rewards lose value is termed the rate of delay discounting. Rates of delay discounting are robust predictors of much behavior of societal importance. One efficient approach to obtaining a human subject's rate of delay discounting is via the 21- and 27-item Monetary Choice Questionnaires, brief dichotomous choice tasks that assess preference between small immediate and larger delayed monetary outcomes. Unfortunately, the scoring procedures for the Monetary Choice Questionnaires are rather complex, which may serve as a barrier to their use. This report details a freely available Excel-based spreadsheet tool that automatically scores Monetary Choice Questionnaire response sets, using both traditional and contemporary/advanced approaches. An overview of the Monetary Choice Questionnaire and its scoring algorithm is provided. We conclude with general considerations for using the spreadsheet tool.

Effects of delay and probability combinations on discounting in humans

To determine discount rates, researchers typically adjust the amount of an immediate or certain option relative to a delayed or uncertain option. Because this adjusting amount method can be relatively time consuming, researchers have developed more efficient procedures. One such procedure is a 5-trial adjusting delay procedure, which measures the delay at which an amount of money loses half of its value (e.g., $1000 is valued at $500 with a 10-year delay to its receipt). Experiment 1 (n=212) used 5-trial adjusting delay or probability tasks to measure delay discounting of losses, probabilistic gains, and probabilistic losses. Experiment 2 (n=98) assessed combined probabilistic and delayed alternatives. In both experiments, we compared results from 5-trial adjusting delay or probability tasks to traditional adjusting amount procedures. Results suggest both procedures produced similar rates of probability and delay discounting in six out of seven comparisons. A magnitude effect consistent with previous research was observed for probabilistic gains and losses, but not for delayed losses. Results also suggest that delay and probability interact to determine the value of money. Five-trial methods may allow researchers to assess discounting more efficiently as well as study more complex choice scenarios.

Body Mass Index and Caloric Value of Rewards as Parameters That Modulate Delay-Discounting Rates

In this study, the contribution of the caloric value of primary rewards in conjunction with the body mass index (BMI) of 124 adolescents on delay-discounting rates was examined. Participants were divided into 4 groups according to their BMI: low weight, normal weight, overweight, and obesity. Subsequently, they estimated the subjective value of the following rewards: fruit, fast food, water, soda, and money, with an adjusting-amount procedure with the following delays: 1 day, 1 week, 1 month, 6 months, 1 year, 3 years, and 5 years. Globally, it was found that fast food and soda showed lower discounting rates than fruit, water, and money. It was also found that while the BMI of the participants increased, the discounting rates of fast food and soda decreased, the rates of water increased, and the rates of money decreased and then increased again. Although in previous research it has been found that primary rewards are discounted at a higher rate than conditioned rewards, like money, the results of this study suggest that both caloric level of primary rewards and BMI of the participants are parameters that modulate the delay-discounting rates. In addition, the findings of this study suggest the existence of a continuous process of discounting that runs with BMI, which is a continuous health index. The form of the relation between these continua depends on variables such as the type of reward tested.

Evidence for Different Trajectories of Delay Discounting in Older Adults With Mild Cognitive Impairment and Mild Alzheimer's Disease.

To examine whether delay discounting (DD) develops differently within individuals diagnosed with mild cognitive impairment (MCI) or mild Alzheimer's disease (AD). We set out to study trajectories of DD in N = 111 older adults (Mage = 75.2 years, range: 55-94, 53% female) with MCI (n = 64) or mild AD (n = 47). Data were repeatedly assessed on three measurement times over a period of 2 years. Results indicated a meaningful difference in the trajectories of DD between MCI and mild AD (t = 2.99, p = .004), with AD patients displaying higher DD rates compared with MCI. Lower intelligence (t = -2.50, p = .013) was related to higher DD. We also found reward-dependent group differences in DD (small: p = .079; medium: p = .258; large: p = .007). Age, functional ability, general cognitive ability, living situation, and marital status were not meaningfully linked to DD (all non significant). Further explorative analyses revealed an increase in DD in patients whose cognitive symptoms had progressed at time 2, compared with more stable courses of mild AD or MCI (diagnosed at time 2). Our results point toward an increase in DD as a function of advanced cognitive decline.

Delay Discounting and Preference Reversals by Cigarette Smokers.

Quit attempts made by smokers that result in relapse to smoking are conceptualized in behavioral economics as preference reversals, in which preference for a larger-later outcome switches to preference for a smaller-sooner outcome. Though preference reversals are predicted by models of delay discounting, we are aware of no human research that has explicitly established that rate of delay discounting is associated with preference reversals. The present study attempted to establish this connection. Assessments of delay discounting of hypothetical money rewards at two magnitudes ($50, $1000) were examined from forty-five smokers, as well as a novel preference reversal task designed to determine when a preference reversal would occur for the same amounts of hypothetical money. Results from the preference reversal task were used to classify participants as predicted high, moderate, and low discounters, and rates of delay discounting were compared between these classifications at each magnitude. Statistically significant differences were observed between predicted high and low discounters in both magnitude conditions, and between predicted high and moderate discounters in the $1000 magnitude condition. Correlations between delay discounting and preference reversal amongst moderate discounters, though in the predicted direction, did not reach statistical significance. The overall pattern of results are consistent with the indication that rate of delay discounting is associated with the timing of preference reversals.