Affect Delay Discounting Research Articles

Recent Experience Affects Delay Discounting: Evidence across Temporal Framing, Signs, and Magnitudes.

Delay discounting, the decrease in outcome value as a function of delay to receipt, is an extensive area of research. How delays are framed (i.e., temporal framing), as well as the sign and magnitude of an outcome, produce important effects on the degree to which outcomes are discounted. Here, we examined how recent experience (i.e., order of presentation) modifies these well-known findings. Experiment 1 examined the effects of temporal framing across gains and losses. Regardless of outcome sign, the order of task presentation affected the effect of temporal framing. In particular, when typical delay frames (e.g., 1 week) preceded delays framed as actual dates (e.g., February 15), discounting was less in the date-framed task. However, when dates were followed by the delay frame, there was no difference in the degree of discounting. The experience of date-framed delays persisted or carried over to the delay-framed task. Experiment 2 examined recent experience and the magnitude effect. In particular, $10 and $100 were discounted similarly between-subjects when it was the first task completed. However, once participants completed the second magnitude task, the magnitude effect was present both within-subjects and across subjects. Furthermore, $10 was discounted more steeply when it followed $100, and $100 was discounted less steeply when it followed $10. The impact of recent experience on delay discounting has important implications for understanding mechanisms that may contribute to delay discounting. Recent experience should be considered when designing delay discounting experiments as well as when implementing interventions to reduce steep delay discounting.

A Change of Scenery: Does Exposure to Images of Nature Affect Delay Discounting and Food Desirability?

A Change of Scenery: Does Exposure to Images of Nature Affect Delay Discounting and Food Desirability?

Previous experience with delays affects delay discounting in animal model of ADHD

BackgroundADHD is a disorder where a common symptom is impulsive behaviour, a broad term associated with making sub-optimal choices. One frequently used method to investigate impulsive behaviour is delay discounting, which involves choosing between a small, immediate reinforcer and a delayed, larger one. Choosing the small immediate reinforcer is by itself, however, not sufficient for terming the choice impulsive, as all organisms eventually switch to choosing the small, immediate reinforcer when the delay to the larger reinforcer becomes long. This switch can be termed impulsive only when it occurs more frequently, or at shorter LL delays, than typically observed in normal controls. A poorly understood aspect is how choice is influenced by previous experience with delays. Using an animal model of Attention-Deficit/Hyperactivity Disorder, the Spontaneously Hypertensive Rat, we manipulated the order of exposure to delays in a delay discounting task. Following a preference test, the Ascending group experienced gradually increasing delays between choice and reinforcer while the Descending group were exposed to these delays in reverse order.ResultsThe results showed that the Descending group chose the small, immediate reinforcer over the larger delayed to a much larger extent than the Ascending group, and continued to do so even when the delay component was ultimately removed. Strain effects were found in the Ascending group, with SHRs switching to the small, immediate reinforcer earlier than controls as the delay to the larger reinforcer increased.ConclusionThe data suggests that delay discounting is affected by history of exposure to delayed consequences. When reinforcement contingencies are incrementally changed from having no response-reinforcer delay to a long delay, discounting of delayed consequences is gradual. However, a sudden change from no delay to a long delay, without intermediate training, results in a rapid switch to the small, immediate reinforcer option, and this behaviour is somewhat resilient to the shortening and eventual removal of the large reinforcer delay. The implication is that attempting to reduce already existing impulsive behaviour in children with ADHD will require gradual habituation and not sudden changes in reinforcement contingencies.

Thinking about neither death nor poverty affects delay discounting, but episodic foresight does: Three replications of the effects of priming on time preferences.

We outline three attempts to replicate experiments that reported priming effects on time preferences measured by delay discounting. Experiment 1 tested the claim that images of poverty prime impulsive choice in people from less affluent backgrounds compared with people from more affluent backgrounds. Experiment 2 tested the claim that mortality salience-thinking about death-primes people to place more value on the future than people who thought about dental surgery. Experiment 3 tested the claim that an episodic foresight manipulation primes greater discounting than no episodic foresight. Experiments 1 and 2 failed to replicate the effects of priming on discount rates. Experiment 3 was a successful and very close replication of the effect of episodic foresight on discount rates.

A Change of Scenery: Does Exposure to Images of Nature Affect Delay Discounting and Food Desirability?

Previous research suggests that exposure to nature may reduce delay discounting (the tendency to discount larger future gains in favor of smaller immediate rewards) and thereby facilitate healthier dietary intake. This pre-registered study examined the impact of online exposure to images of natural scenes on delay discounting and food preferences. It was predicted that exposure to images of natural scenes (vs. images of urban scenes) would be associated with: (i) lower delay discounting; (ii) higher desirability for fruits and vegetables (and lower desirability for more energy-dense foods); and (iii) delay discounting would mediate the effect of nature-image exposure on food desirability. Adult participants (N = 109) were recruited to an online between-subjects experiment in which they viewed a timed sequence of six images either showing natural landscape scenes or urban scenes. They then completed measures of mood, delay discounting (using a five-trial hypothetical monetary discounting task) and rated their momentary desire to eat four fruits and vegetables (F&V), and four energy-dense foods. There was no statistically significant effect of experimental condition (natural vs. urban image exposure) on delay discounting or food desirability. Bayes factors supported the null hypothesis for discounting (BF01 = 4.89), and energy-dense food desirability (BF01 = 7.21), but provided no strong evidence for either hypothesis for F&V desirability (BF01 = 0.78). These findings indicate that brief online exposure to images of nature does not affect momentary impulsivity or energy-dense food preference, whereas for preference for less-energy dense foods, the evidence was inconclusive.

Constructing a Performance Measure of Future Time Orientation

Three studies present the development of the Scrambled Sentences Task for Future Time Orientation (SST-FTO), a performance measure of future time orientation. In Study 1, undergraduate research assistants rated a pool of 30 experimental items as delineating between future and present time orientations demonstrating the content validity of SST-FTO items. Study 2 established the convergent validity of the SST-FTO administered online showing performance related to a self-report measure of time orientation and a performance measure of delay discounting but not to a measure of temporal focus. Study 3 further established the validity of a shortened SST-FTO administered online following an episodic future thinking intervention known to affect delay discounting. The intervention influenced delay discounting but not SST-FTO performance. SST-FTO measures correlated with pre-intervention self-reported future orientation and predicted delay discounting even after accounting for intervention effects and self-reported future orientation. Internal consistency of the measure was demonstrated in all three studies through item-total correlations and Cronbach’s alphas. Results suggested the SST-FTO is a robust performance measure of future time orientation, predictive of decision-making on performance measures of delay discounting.

The neural substrates responsible for how trait anxiety affects delay discounting: Right hippocampal and cerebellar connectivity with bistable right inferior parietal lobule.

Delay discounting, an indicator of impulsivity, refers to the extent of devaluing future rewards. Studies have found that individuals with trait anxiety generally depreciate the later larger rewards, showing steeper delay discounting rates. However, little is known about the neural substrates responsible for how trait anxiety affects individuals' delay discounting. To address this question, we employed the voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) methods to explore the neural substrates of trait anxiety responsible for delay discounting. Behavioral results showed that trait anxiety was significantly positively correlated with delay discounting rates. The VBM analysis revealed that gray matter volumes of the right hippocampus (RHPC) and right cerebellum (RCere) were significantly positively correlated with trait anxiety. Moreover, the RSFC results showed that bistable right inferior parietal lobule (RIPL) connectivity with the RHPC and RCere were all inversely associated with trait anxiety. More importantly, mediation analysis indicated that trait anxiety played a completely mediating role in the relation between functional connectivity of RHPC-RIPL and RCere-RIPL and delay discounting. These results suggested that bistable RIPL connectivity with RHPC and RCere could be neural substrates underlying the effect of trait anxiety on delay discounting. On the whole, the current study yields insights into how trait anxiety affects delay discounting and provides a novel account from a neural basis perspective.

Improving Maladaptive Behavior: The Effect of Episodic Foresight on Delay Discounting and Its Mechanism

Delay discounting is an important part of intertemporal decision-making. This decision involves information about the costs and benefits of future possibilities, which affect people making decision. Episodic foresight therefore has a capacity to organize current action in view of anticipated events and concerns the imaginative of thinking about future events that often draw on the visual modality. In the clinic research, episodic foresight could improve maladaptive behaviors, including pathological gambling, obesity, drug and alcohol abuse. Our study explores the psychological mechanism and brain mechanism. We proposed that future research should further explore how the episodic foresight affects delay discounting and how episodic foresight is applied to clinic and behaviour modification.

Smartphone-based cognitive bias modification training improves healthy food choice in obesity: A pilot study.

Obesity is partly driven by unhealthy food choices underpinned by cognitive biases, including approach bias (a tendency to move towards food cues) and delay discounting (a preference for immediate rewards). Cognitive training strategies aimed at modifying these biases, namely, approach-avoidance training (AAT) and episodic future thinking (EFT), may improve food choice. This pilot randomised trial examined the effect of these two trainings, delivered daily for 1week via smartphone apps, on approach bias for healthy/unhealthy foods, delay discounting for money/food, and hypothetical food choice. Sixty overweight/obese participants (18-45years) were randomly allocated to AAT, EFT, or control. Outcomes were measured at pretraining, posttraining, and 6-week follow-up. AAT reduced approach bias for unhealthy food and increased healthy food choice. However, EFT did not affect delay discounting or food choice. We conclude that AAT is useful for improving food choice in obesity and that smartphones are a feasible, engaging way to deliver training.

An examination of group size and valence in delay discounting of shared outcomes

Previous research has examined delay discounting in a group context, where the outcomes are shared with others. These studies indicate shallow delay discounting in a group context compared to an individual context. The present set of studies aimed to explore the impact of two factors, group size (the number of others in the group) and group valence (liked or disliked others in the group), that may affect delay discounting in a group context. Results of the two studies replicated previous results, where shallow delay discounting was observed in the group context compared to the individual context. While Study 1 indicated no effects of group size nor of valence, Study 2 indicated shallow delay discounting for a larger group compared to a smaller group and for liked others compared to disliked others. These results contribute the nascent literature on delay discounting in group contexts.

Reinforcer magnitude affects delay discounting and influences effects of d-amphetamine in rats

Impulsive choice in humans can be altered by changing reinforcer magnitude; however, this effect has not been found in rats. Current levels of impulsive choice can also influence effects of d-amphetamine. This study used a within-subject assessment to determine if impulsive choice is sensitive to changes in reinforcer magnitude, and whether effects of d-amphetamine are related to current levels of impulsive choice. A discounting procedure in which choice was for a smaller reinforcer available immediately or a larger reinforcer available after a delay that increased within session was used. Reinforcer magnitude was manipulated between conditions and impulsive choice was quantified using area under the curve (AUC). In the Smaller-Magnitude (SM) Condition, choice was between one food pellet and three food pellets. In the Larger-Magnitude (LM) Condition, choice was between two food pellets and six food pellets. Impulsive choice was greater in the SM Condition compared to the LM Condition. Further, effects of d-amphetamine (0.1–1.8mg/kg) were related to differences in impulsive choice. d-Amphetamine increased impulsive choice in the LM Condition, but had no effect on impulsive choice in the SM Condition. Overall, these results show that impulsive choice in rats is sensitive to changes in reinforcer magnitude, and that effects of d-amphetamine are influenced by current levels of impulsive choice.

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

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=25.3years old) orally consumed alcohol (1g/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 insituations 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.

Low-Dose Alcohol Effects on Measures of Inhibitory Control, Delay Discounting, and Risk-Taking

The per se limit for alcohol intoxication in the USA is a blood alcohol concentration (BAC) of 80 mg/100 ml. However, there is abundant evidence that skilled performance (e.g., information processing, motor coordination) is impaired at BACs well below this limit. By contrast, less is known regarding low-dose alcohol effects on impulsivity-related behaviors, including inhibitory control, delay discounting, and risk-taking. Here, we review the evidence to date regarding performance on behavioral impulsivity and decision-making tasks at BACs below the 80 mg/100 ml limit. Overall, below-limit doses of alcohol impair inhibitory control and increase risk-taking but do not affect delay discounting. Within each facet, alcohol effects were largely task-dependent. We discuss the results in relation to above-limit alcohol effects on these measures, as well as implications of these findings in terms of disadvantageous behavior at BACs below the legal level of intoxication.

The mediating role of LPFC–vmPFC functional connectivity in the relation between regulatory mode and delay discounting

Previous studies have shown that regulatory mode orientation can affect many human behaviors, such as risk-taking, counterfactual thinking and economic decision making. However, little is known about how regulatory mode affects delay discounting. To address this question, we used resting-state functional magnetic resonance imaging (rs-fMRI) to investigate whether regulatory mode orientations can be represented by functional connectivity and the influence of two regulatory modes (assessment and locomotion) on delay discounting. The behavioral results showed that delay discounting was negatively correlated with assessment scores but positively correlated with locomotion scores. Neuroimaging results indicated that the functional connectivity between lateral prefrontal cortex (LPFC) and ventromedial prefrontal cortex (vmPFC) was negatively correlated with assessment scores but positively correlated with locomotion scores. Furthermore, mediation analysis showed that the effect of regulatory mode on delay discounting is mediated by LPFC–vmPFC functional connectivity. These results suggested that people’s regulatory mode orientation could predict delay discounting, which is mediated by LPFC–vmPFC functional connectivity. Therefore, the present study extends our perspective on regulatory mode and provides neural mechanism for understanding the link between regulatory mode and delay discounting.

Delay discounting: Concepts and measures.

Delay discounting, one element which underlies decision-making, can be defined as the depreciation of the value of a reward related to the time that it takes to be released. High rates of delay discounting are found in subjects who are willing to forgo greater rewards available only after some length of time and who show a preference for smaller rewards that are available immediately. Widely used as a measure of impulsiveness, delay discounting can be evaluated using experimental tasks. The present review evaluated tasks of delay discounting, their features, measures of evaluation and anomalies, and some variables that can affect delay discounting results and applications in the study of individual and intra-individual differences.

Acute Ethanol Does Not Always Affect Delay Discounting in Rats Selected to Prefer or Avoid Ethanol

The purpose of this study was to determine whether animals predisposed to prefer alcohol possess an altered acute response to alcohol on a delay discounting task relative to animals predisposed to avoid alcohol. We used rats selected to prefer or avoid alcohol to assess whether genotype moderates changes in delay discounting induced by acute ethanol exposure. Selectively bred rat lines of Sardinian alcohol-preferring (sP; n = 8) and non-preferring (sNP; n = 8) rats, and alko alcohol (AA, n = 8) and alko non-alcohol (ANA, n = 8) rats were trained in an adjusting amount task to assess delay discounting. There were no significant effects of line on baseline discounting; however, both lines of alcohol-preferring rats exhibit slowed reaction times. Acute ethanol (0, 0.25, 0.5 g/kg) treatment also had no effect on delay discounting in any of the selectively bred rat lines. Our data indicate that in these lines of animals, alcohol preference or avoidance has no impact on delay discounting following acute ethanol exposure. It is possible that other genetic models or lines may be differentially affected by alcohol and exhibit qualitatively and quantitatively different responses in delay discounting tasks.

Bi-frontal direct current stimulation affects delay discounting choices

In delay discounting tasks, participants decide between receiving a certain amount of money now or a larger sum sometime in the future. This study investigated the effects of transcranial direct current stimulation on delay discounting. Participants made delay discounting choices while receiving a bi-frontal stimulation of right-hemisphere anodal/left-hemisphere cathodal, left-hemisphere anodal/right-hemisphere cathodal, and sham stimulation, in three separate sessions. When the difference between the alternatives was 10% or more, participants generally preferred to wait for the larger sum. Nevertheless, there were more choices of smaller “immediate” gains, instead of the larger delayed options, when the left dorsolateral prefrontal cortex (DLPFC) was facilitated and the right DLPFC inhibited, compared to the sham stimulation. These observations indicate the significant role of the prefrontal cortex in delay discounting choices, and demonstrate that increased left frontal activation combined with decreased right frontal activation can alter decision-making by intensifying a tendency to choose immediate gains.

How social comparison of interpersonal environments affect delay discounting

How social comparison of interpersonal environments affect delay discounting

A money management-based substance use treatment increases valuation of future rewards

Objective A positive association between delay discounting and substance use has been documented; substance users tend to discount future rewards more than non-users. However, studies detailing the responsiveness of delay discounting to interventions are lacking, and few have examined how any behavioral intervention affects delay discounting and whether these effects moderate changes in substance abuse. This study assesses the effectiveness of a money management intervention, Advisor-Teller Money Manager (ATM), in reducing delay discounting over time and the relationship of these effects to changes in cocaine use. Method Ninety psychiatric patients with histories of cocaine and/or alcohol use were randomly assigned to 36-weeks of ATM treatment or to a minimal-attention control condition. Delay discounting and cocaine use were measured throughout the intervention with a 52-week follow up measure of cocaine use. Analyses were conducted of (a) the effect of ATM on slopes of delay discounting and cocaine abstinence and (b) the relationship between change in delay discounting and change in cocaine abstinence. Results The ATM intervention was associated with significantly less delay discounting and less cocaine use over time relative to controls. Increases in delay discounting were associated with decreased abstinence from cocaine. Conclusions ATM treatment decreased delay discounting rates and these effects extended to cocaine use. Concrete conceptualizations of future events, as occur in financial planning, with higher perceived probability may account for higher valuation of future rewards in counseled patients.

Delay discounting and future-directed thinking in anhedonic individuals

Anhedonia (lack of reactivity to pleasurable stimuli) and a negatively skewed view of the future are important components of depression that could affect economic decisions in depressed individuals. Delay discounting paradigms might be useful for probing putative affective and cognitive underpinnings of such decisions. As a first step to evaluate whether difficulties experiencing pleasure might affect delay discounting, 36 undergraduate students with varying levels of anhedonia performed a delay discounting task in which they made choices between a small immediate and larger future monetary reward. Increasing levels of anhedonia (Snaith–Hamilton Pleasure Scale) were negatively associated with delay discounting rate, indicating that anhedonic individuals tended to choose the larger, albeit delayed reward. These correlations remained after controlling for variables previously linked to delay discounting (working memory capacity and impulsivity) and pessimistic future-directed thinking. The current findings provide preliminary evidence indicating that anhedonic individuals make less myopic decisions about their future, possibly due to their decreased responsiveness to immediate rewards.