Delay discounting of different outcomes: Review and theory

Now or Later? Examining Social and Financial Decision Making in Middle-to-Older Aged Adults

OBJECTIVES

Contextually driven decision making is multidimensional, as individuals need to contend with prioritizing both competing and complementary demands. However, data is limited as to whether temporal discounting rates vary as a function of framing (gains vs loss) and domain (monetary vs social) in middle-to-older aged adults. It is also unclear whether socioaffective characteristics like social isolation and loneliness are associated with temporal discounting.

METHODS

Temporal discounting rates were examined across monetary gain, monetary loss, social gain, and social loss conditions in 140 adults aged 50-90 during the Omicron stage of the pandemic. Self-report measures assessed loneliness and social isolation levels.

RESULTS

Results found evidence of steeper temporal discounting rates for gains as compared to losses in both domains. Social outcomes were also more steeply discounted than monetary outcomes, without evidence of an interaction with the framing condition. Socioeconomic and socioaffective factors were unexpectedly not associated with temporal discounting rates.

DISCUSSION

Community-dwelling middle-to-older aged adults showed a preference for immediate rewards and devalued social outcomes more than monetary outcomes. These findings have implications for tailoring social and financial incentive programs for middle to later adulthood.

Hedonic hunger, ultra-processed food consumption, and the moderating effects of impulsivity in pregnant individuals with body mass index ≥ 25

Evidence suggests higher hedonic hunger (preoccupation with/desire to consume food for pleasure) is associated with greater ultra-processed food (UPF) consumption in non-pregnant individuals with higher, but not lower, self-report impulsivity or delay discounting. The current study tested the association between hedonic hunger and UPF consumption, and the moderating effects of self-report impulsivity and delay discounting, during pregnancy. Individuals (N = 220) with body mass index (BMI)≥25 completed the Power of Food Scale, 24-h dietary recalls, and Barratt Impulsiveness Scale-Version 11 in early-mid pregnancy. A subset enrolled in an ancillary study (n = 143) completed a Delay Discounting Task. Linear regression and moderation models covaried for age, gestational age, pre-pregnancy BMI, and socioeconomic status. The association between hedonic hunger and UPF consumption was nonsignificant (p = 0.47). Self-report impulsivity was not a significant moderator (p = 0.11), but delay discounting was (p = 0.01). Simple slopes analysis revealed a one-unit increase in hedonic hunger was associated with 7% lower UPF intake among participants with lower (M+1SD) delay discounting (p = 0.01) and 1% higher UPF intake among those with higher (M-1SD) delay discounting (p = 0.57). Findings contrast those from research with non-pregnant samples and indicate lower delay discounting may serve as a protective factor, associated with reduced UPF consumption at higher levels of hedonic hunger, during pregnancy.

Assessing the relationship between delay discounting and decisions to engage in various protective behaviors during COVID-19

Research suggests that discounting of delayed rewards (i.e., tendency to choose smaller immediate rewards over large later rewards) is a promising target of intervention to encourage compliance with public health measures (PHM), such as vaccination compliance. The effects of delay discounting, however, may differ across the types of PHMs, given that the benefits of vaccination, unlike other PHMs (physical distancing, handwashing, and mask-wearing), are more temporally delayed. Here, we examined whether delay discounting predicts engaging in COVID-19 PHMs in approximately 7,000 participants recruited from 13 countries in June-August 2021. After controlling for demographic and distress variables, delay discounting was a negative predictor of vaccination, but a positive predictor of physical distancing (when restrictions are in place) and handwashing. There was no significant association between delay discounting and frequency of mask-wearing. It is possible that increasing vaccination compliance may require greater emphasis on future benefits of vaccination, whereas promotion of physical distancing and hand hygiene may require greater focus on the present moment. Further research is needed to investigate the nature of this relationship and its implications for public health messaging.

Human laboratory models of reward in substance use disorder

Human laboratory models in substance use disorder provide a key intermediary step between highly controlled and mechanistically informative non-human preclinical methods and clinical trials conducted in human populations. Much like preclinical models, the variety of human laboratory methods provide insights into specific features of substance use disorder rather than modelling the diverse causes and consequences simultaneously in a single model. This narrative review provides a discussion of popular models of reward used in human laboratory research on substance use disorder with a focus on the specific contributions that each model has towards informing clinical outcomes (forward translation) and analogs within preclinical models (backward translation). Four core areas of human laboratory research are discussed: drug self-administration, subjective effects, behavioral economics, and cognitive and executive function. Discussion of common measures and models used, the features of substance use disorder that these methods are purported to evaluate, unique issues for measure validity and application, and translational links to preclinical models and special considerations for studies wishing to evaluate homology across species is provided.

A systematic review and meta-analysis of test-retest reliability and stability of delay and probability discounting

In this meta-analysis, we describe a benchmark value of delay and probability discounting reliability and stability that might be used to (a) evaluate the meaningfulness of clinically achieved changes in discounting and (b) support the role of discounting as a valid and enduring measure of intertemporal choice. We examined test-retest reliability, stability effect sizes (dz; Cohen, 1992), and relevant moderators across 30 publications comprising 39 independent samples and 262 measures of discounting, identified via a systematic review of PsychInfo, PubMed, and Google Scholar databases. We calculated omnibus effect-size estimates and evaluated the role of proposed moderators using a robust variance estimation meta-regression method. The meta-regression output reflected modest test-retest reliability, r = .670, p < .001, 95% CI [.618, .716]. Discounting was most reliable when measured in the context of temporal constraints, in adult respondents, when using money as a medium, and when reassessed within 1 month. Testing also suggested acceptable stability via nonsignificant and small changes in effect magnitude over time, dz = 0.048, p = .31, 95% CI [-0.051, 0.146]. Clinicians and researchers seeking to measure discounting can consider the contexts when reliability is maximized for specific cases.

An apparatus and procedure for studying discounting of real outcomes of money and aversive sound

We developed and examined a laboratory preparation with adult humans that pits shorter term avoidance over longer term positive reinforcement and may serve as a useful laboratory functional analogue of problematic behavior. Participants were exposed to choices between (1) avoiding an aversive sound and acquiring no money or (2) listening to an aversive sound for a set duration and then receiving money. The first choice, avoiding an aversive sound and acquiring no money, was conceptualized as immediate negative reinforcement and no positive reinforcement, whereas the latter choice, listening to an aversive sound for a set duration and then receiving money, was conceptualized as a potential positive punisher paired with a larger later positive reinforcer. We manipulated the duration of the sound and the magnitude of money to identify the point at which individual participants' choices changed from avoiding the sound to choosing the sound plus money. As the sound duration increased, the choice of listening to the sound and receiving money decreased. Similar functions were observed with two different monetary magnitudes. The model has potential applicability to real-world problems such as smoking, addiction, gambling, anxiety disorders, and other impulse control disorders.

Differences in Discounting Behavior and Brain Responses for Food and Money Reward

Most neuroeconomic research seeks to understand how value influences decision-making. The influence of reward type is less well understood. We used functional magnetic resonance imaging (fMRI) to investigate delay discounting of primary (i.e., food) and secondary rewards (i.e., money) in 28 healthy, normal-weighted participants (mean age = 26.77; 18 females). To decipher differences in discounting behavior between reward types, we compared how well-different option-based statistical models (exponential, hyperbolic discounting) and attribute-wise heuristic choice models (intertemporal choice heuristic, dual reasoning and implicit framework theory, trade-off model) captured the reward-specific discounting behavior. Contrary to our hypothesis of different strategies for different rewards, we observed comparable discounting behavior for money and food (i.e., exponential discounting). Higher k values for food discounting suggest that individuals decide more impulsive if confronted with food. The fMRI revealed that money discounting was associated with enhanced activity in the right dorsolateral prefrontal cortex, involved in executive control; the right dorsal striatum, associated with reward processing; and the left hippocampus, involved in memory encoding/retrieval. Food discounting, instead, was associated with higher activity in the left temporoparietal junction suggesting social reinforcement of food decisions. Although our findings do not confirm our hypothesis of different discounting strategies for different reward types, they are in line with the notion that reward types have a significant influence on impulsivity with primary rewards leading to more impulsive choices.

Been There, Done That: The Impact of the Novelty of Penile Vaginal Intercourse (PVI) and Participants' Sex on Delay and Probability Discounting of PVI

Delay and probability discounting tasks are useful for understanding aspects of decision making. The current study, which employed a mixed-model design to assess discounting of penile-vaginal intercourse (PVI), was conducted online with male and female participants recruited from Prolific (N = 300; mean age = 34.1 years). Results of the novel delay and probability discounting tasks indicated that as the delay to PVI increased, or as PVI became less certain to occur, participants were instead more likely to choose to receive oral sex, the reward initially indicated as less desirable. Having previously engaged in PVI, however, enhanced this reversal of preferences on both tasks, which suggests PVI loses some of its value when no longer novel. Males and females similarly discounted PVI on the delay discounting task, which suggests biological sex may not impact the propensity to wait for a preferred sexual behavior. On the probability discounting task, however, males were more averse to a reduced probability of PVI occurring and instead opted for receiving oral sex. The sexual behavior discounting tasks developed in the current study, and ones like it, may prove useful for identifying preferences in sexual behaviors, and ultimately enhance sexual and relationship satisfaction.

Gender differences in the effects of emotion induction on intertemporal decision-making

'Good things come to those who wait' is a popular saying, which goes along with numerous daily life decisions requiring trade-offs between immediate-small and later-larger rewards; however, some individuals have a tendency to prefer sooner rewards while discounting the value of delayed rewards, known as delay discounting. The extant literature indicates that emotions and gender can modulate intertemporal choices, but their interplay remains hitherto poorly investigated. Here, 308 participants were randomized to different conditions, inducing distinct emotions-fear, joy, a neutral state-through standardized movie clips, and then completed a computerized delay discounting task for hypothetical money rewards. Following the induction of fear, women discount the future steeper than men, thus preferring immediate-smaller rewards rather than larger-delayed ones. Also, women were more prone to choose immediate rewards when in a fearful condition than when in a positive state of joy/happiness. By contrast, men were unaffected by their emotional state when deciding on monetary rewards. Our findings provide evidence that fear can trigger different intertemporal choices according to gender, possibly reflecting the adoption of different evolutionary strategies.

Delay of punishment highlights differential vulnerability to developing addiction-like behavior toward sweet food

Resistance to punishment is commonly used to measure the difficulty in refraining from rewarding activities when negative consequences ensue, which is a hallmark of addictive behavior. We recently developed a progressive shock strength (PSS) procedure in which individual rats can titrate the amount of punishment that they are willing to tolerate to obtain food rewards. Here, we investigated the effects of a range of delays (0-12 s) on resistance to punishment measured by PSS break points. As expected from delay discounting principles, we found that delayed shock was less effective as a punisher, as revealed by higher PSS breakpoints. However, this discounting effect was not equally distributed in the population of rats, and the introduction of a delay highlighted the existence of two populations: rats that were sensitive to immediate punishment were also sensitive to delayed shock, whereas rats that were resistant to immediate punishment showed strong temporal discounting of delayed punishment. Importantly, shock-sensitive rats suppressed responding even in subsequent non-punishment sessions, and they differed from shock-resistant rats in anxiety-like behavior, but not in sensitivity to pain. These results show that manipulation of temporal contingencies of punishment in the PSS procedure provides a valuable tool to identify individuals with a double vulnerability to addiction: low sensitivity to aversion and excessive discounting of negative future consequences. Conversely, the shock-sensitive population may provide a model of humans who are vulnerable to opportunity loss due to excessive anxiety.

Designing and Validating a Novel Method for Assessing Delay Discounting Associated With Health Behaviors: Ecological Momentary Assessment Study

BACKGROUND

Delay discounting quantifies an individual's preference for smaller, short-term rewards over larger, long-term rewards and represents a transdiagnostic factor associated with numerous adverse health outcomes. Rather than a fixed trait, delay discounting may vary over time and place, influenced by individual and contextual factors. Continuous, real-time measurement could inform adaptive interventions for various health conditions.

OBJECTIVE

The goals of this paper are 2-fold. First, we present and validate a novel, short, ecological momentary assessment (EMA)-based delay discounting scale we developed. Second, we assess this tool's ability to reproduce known associations between delay discounting and health behaviors (ie, substance use and craving) using a convenience-based sample.

METHODS

Participants (N=97) were adults (age range 18-71 years), recruited on social media. In phase 1, data were collected on participant sociodemographic characteristics, and delay discounting was evaluated via the traditional Monetary Choice Questionnaire (MCQ) and our novel method (ie, 7-item time-selection and 7-item monetary-selection scales). During phase 2 (approximately 6 months later), participants completed the MCQ, our novel delay discounting measures, and health outcomes questions. The correlations between our method and the traditional MCQ within and across phases were examined. For scale reduction, a random number of items were iteratively selected, and the correlation between the full and random scales was assessed. We then examined the association between our time- and monetary-selection scales assessed during phase 2 and the percentage of assessments that participants endorsed using or craving alcohol, tobacco, or cannabis.

RESULTS

In total, 6 of the 7 individual time-selection items were highly correlated with the full scale (r>0.89). Both time-selection (r=0.71; P<.001) and monetary-selection (r=0.66; P<.001) delay discounting rates had high test-retest reliability across phases 1 and 2. Phase 1 MCQ delay discounting function highly correlated with phase 1 (r=0.76; P<.001) and phase 2 (r=0.45; P<.001) time-selection delay discounting scales. One or more randomly chosen time-selection items were highly correlated with the full scale (r>0.94). Greater delay discounting measured via the time-selection measure (adjusted mean difference=5.89, 95% CI 1.99-9.79), but not the monetary-selection scale (adjusted mean difference=-0.62, 95% CI -3.57 to 2.32), was associated with more past-hour tobacco use endorsement in follow-up surveys.

CONCLUSIONS

This study evaluated a novel EMA-based scale's ability to validly and reliably assess delay discounting. By measuring delay discounting with fewer items and in situ via EMA in natural environments, researchers may be better able to identify individuals at risk for poor health outcomes.

Developmental deviation in delay discounting as a transdiagnostic indicator of risk for child psychopathology

BACKGROUND

The tendency to prefer smaller, immediate rewards over larger, delayed rewards is known as delay discounting (DD). Developmental deviations in DD may be key in characterizing psychiatric and neurodevelopmental disorders. Recent work empirically supported DD as a transdiagnostic process in various psychiatric disorders. Yet, there is a lack of research relating developmental changes in DD from mid-childhood to adolescence to psychiatric and neurodevelopmental disorders. Additionally, examining the interplay between socioeconomic status/total household income (THI) and psychiatric symptoms is vital for a more comprehensive understanding of pediatric pathology and its complex relationship with DD.

METHODS

The current study addresses this gap in a robust psychiatric sample of 1843 children and adolescents aged 5-18 (M = 10.6, SD = 3.17; 1,219 males, 624 females). General additive models (GAMs) characterized the shape of age-related changes in monetary and food reward discounting for nine psychiatric disorders compared with neurotypical youth (NT; n = 123). Over 40% of our sample possessed a minimum of at least three psychiatric or neurodevelopmental disorders. We used bootstrap-enhanced Louvain community detection to map DD-related comorbidity patterns. We derived five subtypes based on diagnostic categories present in our sample. DD patterns were then compared across each of the subtypes. Further, we evaluated the effect of cognitive ability, emotional and behavioral problems, and THI in relation to DD across development.

RESULTS

Higher discounting was found in six of the nine disorders we examined relative to NT. DD was consistently elevated across development for most disorders, except for depressive disorders, with age-specific DD differences compared with NTs. Community detection analyses revealed that one comorbidity subtype consisting primarily of Attention-Deficit/Hyperactivity Disorder (ADHD) Combined Presentation and anxiety disorders displayed the highest overall emotional/behavioral problems and greater DD for the food reward. An additional subtype composed mainly of ADHD, predominantly Inattentive Presentation, learning, and developmental disorders, showed the greatest DD for food and monetary rewards compared with the other subtypes. This subtype had deficits in reasoning ability, evidenced by low cognitive and academic achievement performance. For this ADHD-I and developmental disorders subtype, THI was related to DD across the age span such that participants with high THI showed no differences in DD compared with NTs. In contrast, participants with low THI showed significantly worse DD trajectories than all others. Our results also support prior work showing that DD follows nonlinear developmental patterns.

CONCLUSIONS

We demonstrate preliminary evidence for DD as a transdiagnostic marker of psychiatric and neurodevelopmental disorders in children and adolescents. Comorbidity subtypes illuminate DD heterogeneity, facilitating the identification of high-risk individuals. Importantly, our findings revealed a marked link between DD and intellectual reasoning, with children from lower-income households exhibiting lower reasoning skills and heightened DD. These observations underscore the potential consequences of compromised self-regulation in economically disadvantaged individuals with these disorders, emphasizing the need for tailored interventions and further research to support improved outcomes.

Smoking Dependence, Time-Discounting, and Sustained Cessation Behavior: A Longitudinal Study of Predominantly Light Smokers

INTRODUCTION

This study aimed to assess whether two established psychosocial predictors of smoking abstinence, nicotine dependence and time-discounting, also apply to a population of predominantly cigarette light smokers, which is the dominant pattern of smoking in countries like Mexico. Relatively infrequent smoking is increasingly prevalent, yet still harmful, making it important to understand the predictors of cessation in this population.

AIMS AND METHODS

Mexican adult smokers recruited from an online consumer panel were surveyed every 4 months between November 2018 and July 2020. We considered respondents who reported a quit attempt in between surveys (n = 1288). Dependence was measured with a 10-item version of the Wisconsin Inventory of Smoking Dependence Motives (WISDM). Time-discounting was assessed with five branching questions about hypothetical reward scenarios. Logistic models regressed sustained quit attempts (≥30 days of abstinence) at time t + 1 on study variables at time t.

RESULTS

We found strong interitem reliability (α = 0.92) and intraindividual consistency of our brief WISDM (ρ = 0.68), but moderate intraindividual consistency of the time-discounting measure (ρ = 0.48). Forty-eight percent of the sample reported sustained quit attempts, and 79% were non-daily or light daily smokers (≤5 cigarettes per day). Smokers with higher WISDM-10 had lower odds of sustained quitting and this result remained when controlling for smoking frequency and the Heaviness of Smoking Index (adjusted odds ratio [AOR] = 0.768). Time-discounting was unassociated with sustained quitting.

CONCLUSIONS

Our findings suggest that a brief, 10-item multidimensional measure of dependence is useful for predicting sustained quitting in a context of relatively light smoking; time-discounting appears less relevant, although our results are not conclusive because of the low test-retest reliability of our measure.

IMPLICATIONS

Given the increase in non-daily and light daily cigarette smoking in many countries, including in Mexico, and the health risks this still poses, it is important to understand the predictors of cessation among relatively light smokers. The WISDM-10 multidimensional measure seems to be a good instrument to assess dependence and predict successful quitting in this population, and possibly more appropriate than physical dependence measures. As such, it could help design and target more suitable cessation treatments for non-daily and daily light cigarette smokers. While this study did not find time-discounting to be a relevant predictor of smoking abstinence, future studies should explore other measures.

Active and passive waiting in impulsive choice: Effects of fixed-interval and fixed-time delays

Behavioral interventions to improve self-control, preference for a larger-later (LL) reward over a smaller-sooner (SS) reward, involve experience with delayed rewards. Whether they involve timing processes remains controversial. In rats, there have been inconsistent results on whether timing processes may be involved in intervention-induced improvements in self-control. Interventions that improved self-control with corresponding timing improvements used fixed-interval (FI) delays, whereas interventions that failed to find corresponding timing improvements used fixed-time (FT) delays. The FI schedule includes a response contingency (active waiting), whereas the FT schedule delivers reward automatically (passive waiting). The present study compared the effects of FI and FT schedules in interventions and impulsive choice tasks to evaluate effects on self-control and timing behavior. The impulsive choice task evaluated preference for an SS option (one pellet after 10-, 15-, 20-, 25-, and 30-s delays) versus an LL option (two pellets after a 30-s delay). The intervention task included forced-choice SS (one pellet after 10 s) and LL (two pellets after 30 s) sessions under FI or FT schedules. FI schedules produced greater sensitivity to SS delay in the impulsive choice task. Both FI and FT interventions increased LL choices. Following choice testing, temporal bisection and peak interval tasks revealed better timing precision for rats with an FI delay experience. Overall, the FI choice contingency was associated with improved temporal attention and timing precision.

Laboratory method to induce state boredom increases impulsive choice in people who use cocaine and controls

Background: Impulsive choice is associated with both cocaine use and relapse. Little is known about the influence of transient states on impulsive choice in people who use cocaine (PWUC).Objective: This study investigated the direct effects of induced boredom on impulsive choice (i.e., temporal discounting) in PWUC relative to well-matched community controls.Methods: Forty-one PWUC (≥1× cocaine use in past 3 months; 7 females) and 38 demographically matched controls (5 females) underwent two experimental conditions in counterbalanced order. Temporal discounting was assessed immediately after a standardized boredom induction task (peg-turning) and a self-selected video watched for the same duration (non-boredom). Subjective mood state and perceived task characteristics were assessed at baseline, during experimental manipulations, and after the choice task.Results: PWUC and controls were well matched on sex, age, and socioeconomic status. Groups were also similar in reported use of drugs other than cocaine, except for recent cigarette and alcohol use (PWUC > controls). As expected, peg-turning increased boredom in the sample overall, with higher boredom reported during peg-turning than the video (p < .001, η2p = .20). Participants overall exhibited greater impulsive choice after boredom than non-boredom (p = .028, η2p = .07), with no preferential effects in PWUC (p > .05, BF01 = 2.9).Conclusion: Experimentally induced boredom increased state impulsivity irrespective of cocaine use status - in PWUC and carefully matched controls - suggesting a broad link between boredom and impulsive choice. This is the first study to show that transient boredom directly increases impulsive choice. Data support a viable laboratory method to further parse the effects of boredom on impulsive choice.

Using behavioral economics to optimize safer undergraduate late-night transportation

Many universities sponsor student-oriented transit services that could reduce alcohol-induced risks but only if services adequately anticipate and adapt to student needs. Human choice data offer an optimal foundation for planning and executing late-night transit services. In this simulated choice experiment, respondents opted to either (a) wait an escalating delay for a free university-sponsored "safe" option, (b) pay an escalating fee for an on-demand rideshare service, or (c) pick a free, immediately available "unsafe" option (e.g., ride with an alcohol-impaired driver). Behavioral-economic nonlinear models of averaged-choice data describe preference across arrangements. Best-fit metrics indicate adequate sensitivity to contextual factors (i.e., wait time, preceding late-night activity). At short delays, students preferred the free transit option. As delays extend beyond 30 min, most students preferred competing alternatives. These data depict a policy-relevant delay threshold to better safeguard undergraduate student safety.

Deadlines make you productive, but what do they do to your motivation? Trajectories in quantity and quality of motivation and study activities among university students as exams approach

Introduction

Recent research has emphasized that achievement motivation is context-sensitive and varies within individual students. Ubiquitous temporal landmarks such as exams or deadlines are evident contextual factors that could systematically explain variation in motivation. Indeed, research has consistently found that university students increase their study efforts as exams come closer in time, indicating increasing study motivation. However, changes in study motivation for a specific exam as it comes closer have rarely been investigated. Instead, research on developmental changes in expectancy and value beliefs has consistently founds that achievement motivation declines over a semester. Surprisingly, declining motivation thus apparently coincides with increasing study efforts for end-of-semester exams.

Methods

The present research investigates this apparent contradiction by assessing how exam-specific motivation and study behavior change under equal methodological conditions as an exam draws closer. Using parallel growth curve models, we examine changes in expectancy-value beliefs, performance approach and avoidance motivation and study behavior as well as motivational want- and should-conflicts among 96 students over eight weekly measurement points.

Results and discussion

Results show that students study more for their exam as it comes closer and increase their use of surface learning strategies more rapidly than their use of deep learning strategies. However, even exam-specific expectancy and attainment value beliefs decline while performance-avoidance motivation increases over time, indicating that students increasingly study out of fear to fail as exams come closer. Consistent with these findings, students' experience of should conflicts decreases while their want conflicts increase over time. We discuss several possible mechanisms underlying our findings in addition to potential theoretical consequences and suggest future research opportunities to better understand students' changes in situative motivation and study behavior in the context of temporal landmarks.

Poke And Delayed Drink Intertemporal Choice Task (POKE-ADDICT): An open-source behavioral apparatus for intertemporal choice testing in rodents

Advancements in neuroscience research present opportunities and challenges, requiring substantial resources and funding. To address this, we describe here "Poke And Delayed Drink Intertemporal Choice Task (POKE-ADDICT)", an open-source, versatile, and cost-effective apparatus for intertemporal choice testing in rodents. This allows quantification of delay discounting (DD), a cross-species phenomenon observed in decision making which provides valuable insights into higher-order cognitive functioning. In DD, the subjective value of a delayed reward is reduced as a function of the delay for its receipt. Using our apparatus, we implemented an effective intertemporal choice paradigm for the quantification of DD based on an adjusting delayed amount (ADA) algorithm using mango juice as a reward. Our paradigm requires limited training, a few 3D-printed parts and inexpensive electrical components, including a Raspberry Pi control unit. Furthermore, it is compatible with several in vivo procedures and the use of nose pokes instead of levers allows for faster task learning. Besides the main application described here, the apparatus can be further extended to implement other behavioral tests and protocols, including standard operant conditioning. In conclusion, we describe a versatile and cost-effective design based on Raspberry Pi that can support research in animal behavior, decision making and, more specifically, delay discounting.

Mechanisms of impulsive choice: Experiments to explore and models to map the empirical terrain

Impulsive choice is preference for a smaller-sooner (SS) outcome over a larger-later (LL) outcome when LL choices result in greater reinforcement maximization. Delay discounting is a model of impulsive choice that describes the decaying value of a reinforcer over time, with impulsive choice evident when the empirical choice-delay function is steep. Steep discounting is correlated with multiple diseases and disorders. Thus, understanding the processes underlying impulsive choice is a popular topic for investigation. Experimental research has explored the conditions that moderate impulsive choice, and quantitative models of impulsive choice have been developed that elegantly represent the underlying processes. This review spotlights experimental research in impulsive choice covering human and nonhuman animals across the domains of learning, motivation, and cognition. Contemporary models of delay discounting designed to explain the underlying mechanisms of impulsive choice are discussed. These models focus on potential candidate mechanisms, which include perception, delay and/or reinforcer sensitivity, reinforcement maximization, motivation, and cognitive systems. Although the models collectively explain multiple mechanistic phenomena, there are several cognitive processes, such as attention and working memory, that are overlooked. Future research and model development should focus on bridging the gap between quantitative models and empirical phenomena.

Neuronal implementation of the temporal difference learning algorithm in the midbrain dopaminergic system

The temporal difference learning (TDL) algorithm has been essential to conceptualizing the role of dopamine in reinforcement learning (RL). Despite its theoretical importance, it remains unknown whether a neuronal implementation of this algorithm exists in the brain. Here, we provide an interpretation of the recently described signaling properties of ventral tegmental area (VTA) GABAergic neurons and show that a circuitry of these neurons implements the TDL algorithm. Specifically, we identified the neuronal mechanism of three key components of the TDL model: a sustained state value signal encoded by an afferent input to the VTA, a temporal differentiation circuit formed by two types of VTA GABAergic neurons the combined output of which computes momentary reward prediction (RP) as the derivative of the state value, and the computation of reward prediction errors (RPEs) in dopamine neurons utilizing the output of the differentiation circuit. Using computational methods, we also show that this mechanism is optimally adapted to the biophysics of RPE signaling in dopamine neurons, mechanistically links the emergence of conditioned reinforcement to RP, and can naturally account for the temporal discounting of reinforcement. Elucidating the implementation of the TDL algorithm may further the investigation of RL in biological and artificial systems.

Selective chemogenetic inactivation of corticoaccumbal projections disrupts trait choice impulsivity

Impulsive choice has enduring trait-like characteristics and is defined by preference for small immediate rewards over larger delayed ones. Importantly, it is a determining factor in the development and persistence of substance use disorder (SUD). Emerging evidence from human and animal studies suggests frontal cortical regions exert influence over striatal reward processing areas during decision-making in impulsive choice or delay discounting (DD) tasks. The goal of this study was to examine how these circuits are involved in decision-making in animals with defined trait impulsivity. To this end, we trained adolescent male rats to stable behavior on a DD procedure and then re-trained them in adulthood to assess trait-like, conserved impulsive choice across development. We then used chemogenetic tools to selectively and reversibly target corticostriatal projections during performance of the DD task. The prelimbic region of the medial prefrontal cortex (mPFC) was injected with a viral vector expressing inhibitory designer receptors exclusively activated by designer drugs (Gi-DREADD), and then mPFC projections to the nucleus accumbens core (NAc) were selectively suppressed by intra-NAc administration of the Gi-DREADD actuator clozapine-n-oxide (CNO). Inactivation of the mPFC-NAc projection elicited a robust increase in impulsive choice in rats with lower vs. higher baseline impulsivity. This demonstrates a fundamental role for mPFC afferents to the NAc during choice impulsivity and suggests that maladaptive hypofrontality may underlie decreased executive control in animals with higher levels of choice impulsivity. Results such as these may have important implications for the pathophysiology and treatment of impulse control, SUDs, and related psychiatric disorders.

The endowment effect and temporal discounting of drug and non-drug commodities

OBJECTIVES

Despite a rich history of behavioral economic research on substance use there remains a need for further exploration of behavioral mechanisms that may underlie the etiology or persistence of substance use disorder. The purpose of this study was to measure the association between delay discounting and the endowment effect in people who smoke cigarettes, use cocaine, and controls, using online crowdsourcing.

METHODS

Participants were categorized to a cocaine group (n = 36), cigarette group (n = 48), or control group (n = 47) based on recent reported drug use. Based on group, participants completed up to three delay discounting tasks (i.e., money, cigarettes and cocaine), an endowment effect task for multiple commodities, and other questionnaires.

RESULTS

Participants in the cocaine and cigarette group demonstrated an increased rate in discounting for money compared to controls. Participants in the cocaine group had a less pronounced endowment effect for beer, compared to controls, as suggested by willingness to accept less to sell beer. A significant negative association was found between endowment ratios for non-drug commodities and delay discounting for cigarettes, but not monetary or cocaine delay discounting, indicating an inconsistent relationship between the two measures.

CONCLUSIONS

These results support prior research demonstrating a relationship between cocaine and cigarette use and delay discounting and extend that work by measuring the association between delay discounting and the endowment effect. Future research should include both loss aversion and endowment effect tasks and compare their relationship with delay discounting among people that use drugs.

Parents, but not their children, demonstrate greater delay discounting with resource scarcity

BACKGROUND

Individuals with obesity tend to discount the future (delay discounting), focusing on immediate gratification. Delay discounting is reliably related to indicators of economic scarcity (i.e., insufficient resources), including lower income and decreased educational attainment in adults. It is unclear whether the impact of these factors experienced by parents also influence child delay discounting between the ages of 8 and 12-years in families with obesity.

METHODS

The relationship between indices of family income and delay discounting was studied in 452 families with parents and 6-12-year-old children with obesity. Differences in the relationships between parent economic, educational and Medicaid status, and parent and child delay discounting were tested.

RESULTS

Results showed lower parent income (p = 0.019) and Medicaid status (p = 0.021) were differentially related to greater parent but not child delay discounting among systematic responders.

CONCLUSIONS

These data suggest differences in how indicators of scarcity influence delay discounting for parents and children, indicating that adults with scarce resources may be shaped to focus on immediate needs instead of long-term goals. It is possible that parents can reduce the impact of economic scarcity on their children during preadolescent years. These findings suggest a need for policy change to alleviate the burden of scarce conditions and intervention to modify delay discounting rate and to improve health-related choices and to address weight disparities.

Discounting of Hyper-Palatable Food and Money: Associations with Food Addiction Symptoms

INTRODUCTION

Delay discounting (DD), the tendency to prefer small, immediate rewards over larger, delayed rewards, is associated with health-risk behaviors. The study examined associations between DD for money and hyper-palatable foods (HPF) with food addiction (FA) symptoms among a general population sample.

METHODS

Participants (N = 296) completed an adjusting DD task that consisted of a single-commodity condition with HPF as the reward (HPF now vs. HPF later) and cross-commodity conditions comparing money and HPF (money now vs. HPF later; HPF now vs. money later). The Yale Food Addiction Scale 2.0 was used to assess FA symptoms. Zero-inflated negative binomial regression models tested whether discounting of HPF and money was associated with FA symptoms.

RESULTS

Findings indicated there were no significant associations between DD and FA symptoms in the single-commodity HPF condition (logit: OR = 1.02, p-value = 0.650; count: IRR = 1.04, p-value = 0.515). There were no significant associations among cross-commodity conditions comparing money now vs. HPF later (logit: OR = 0.96, p-value = 0.330; count: IRR = 1.02, p-value = 0.729) or conditions comparing HPF now vs. money later (logit: OR = 1.02, p-value = 0.682; count: IRR = 0.92, p-value = 0.128) and FA symptoms.

CONCLUSIONS

Discounting HPF may not be a key behavioral feature among individuals who endorse FA symptoms.

Reliability and validity of behavioral-economic measures: A review and synthesis of discounting and demand

This review sought to synthesize the literature on the reliability and validity of behavioral-economic measures of demand and discounting in human research, introduce behavioral-economic research methodologies for studying addictive behaviors, discuss gaps in the current literature, and review areas for future research. A total of 34 studies was included in this review. The discounting literature showed similar responding regardless of whether hypothetical or actual outcomes were used, though people tended to discount the outcome presented first more steeply, suggesting order effects. Although delay-discounting measures seem to show temporal stability, exceptions were found for probability- and experiential-discounting tasks. The demand literature also demonstrated similar responding regardless of outcome type; however, some demand indices showed exceptions. Randomized price sequences tended to show modest increases in Omax and α and modestly higher rates of inconsistent or nonsystematic responses compared with sequential price sequences. Demand indices generally showed temporal stability, although the stability was weaker the larger the time interval between test sessions. Future studies would benefit by examining addictive commodities beyond alcohol, nicotine, and money; examining temporal stability over longer time intervals; using larger delays in discounting tasks; and using larger sample sizes.

To produce or not to produce? Contrasting the effect of substance abuse in social decision-making situations

Substance use disorders (SUD) have been related to high criminal justice costs, expensive healthcare, social impairment, and decision-making deficits. In non-social decision-making tasks, people with SUD tend to take more risks and choose small immediate rewards than controls. However, few studies have explored how people with SUD behave in social decision-making situations where the resources and profits depend directly on participants' real-time interaction, i.e., social foraging situations. To fulfill this gap, we developed a real-time interaction task to (a) compare the proportion of producers (individuals who tend to search for food sources) and scroungers (individuals who tend to steal or join previously discovered food sources) among participants with SUD and controls with respect to the optimal behavior predicted by the Rate Maximization Model, and (b) explore the relationship between social foraging strategies, prosocial behavior, and impulsivity. Here participants with SUD (n = 20) and a non-user control group (n = 20) were exposed to the Guaymas Foraging task (GFT), the Social Discounting task (SD), and the Delay Discounting task (DD). We found that participants in the control group tended to produce more and obtain higher profits in contrast to substance abuser groups. Additionally, SD and DD rates were higher for scroungers than producers regardless of the group. Our results suggest that producers tend to be more altruistic and less impulsive than scroungers. Knowing more about social strategies and producers' characteristics could help develop substance abuse prevention programs.

Effects of economic context and reward amount on delay and probability discounting

Steep delay and shallow probability discounting are associated with myriad problem behaviors; thus, it is important to understand factors that influence the degree of discounting. The present study evaluated the effects of economic context and reward amount on delay and probability discounting. Two hundred thirteen undergraduate psychology students completed four delay- or probability-discounting tasks. Participants were exposed to hypothetical narratives involving four bank amounts ($750, $12,000, $125,000, and $2,000,000). The delayed/probabilistic amount was $3,000 for the two smaller bank amounts and $500,000 for the two larger bank amounts. The discounting tasks included five delays to, or probabilities of, receipt of the larger amount. The area under the empirical discounting function was calculated for each participant. Participants discounted delayed and uncertain outcomes more when the bank amount was smaller than the outcome (i.e., the economic context was low). Participants discounted the delayed larger amounts less than delayed smaller amounts, even when the relative economic context was the same. In contrast, probability discounting did not differ across magnitudes, which suggests that economic context may attenuate the magnitude effect in probability discounting. The results further highlight the importance of considering the economic context in delay and probability discounting.

COVID-19-related financial scarcity is associated with greater delay discounting but not probability discounting

Prior studies suggest that scarcity increases delay discounting (devaluation of delayed outcomes) and disturbs other decision-making processes. Evidence on the effect of COVID-19 on delay discounting is mixed. Also, no study has examined the effect of COVID-19-related scarcity on probability discounting (devaluation of probabilistic outcomes). The goal of the study was to examine cross-sectional associations between financial impact during the COVID-19 pandemic, delay discounting, and probability discounting. During April 2020, 1012 participants with low income were recruited on Amazon Mechanical Turk and completed measures of delay and probability discounting, perceived COVID-19-related financial impacts, and food security. Regression analyses indicate that compared to those with no COVID-19-related financial impacts, those with severe COVID-19-related financial impacts had greater delay discounting of money and greater delay discounting of a grocery gift card. Also, greater food insecurity in the past month was associated with greater delay discounting of a grocery gift card but not delay discounting of money. Perceived COVID-19 related financial impact was not associated with probability discounting. Combined with laboratory experiments, this study provides additional support for the idea that feelings of scarcity may increase delay discounting. However, as this study was observational, no assumptions of causality should be made about the specific effect of COVID-19 on delay discounting.

Development of a measure of aggressive behavior expectancies in adults: The Aggression Expectancy Questionnaire

According to sociocognitive theories, aggression is learned and elicited through a series of cognitive processes, such as expectancies, or the various consequences that an individual considers more or less likely following aggressive behavior. The current manuscript describes a measurement development project that ultimately yielded a 16-item measure of positive and negative aggression expectancies suitable for use in adult populations. Across two content generation surveys, two preliminary item refinement studies, and three full studies, we took an iterative approach and administered large item pools to several samples and refined item content through a combination of empirical (i.e., factor loadings, model fit) and conceptual (i.e., content breadth, non-redundancy) considerations. The Aggression Expectancy Questionnaire displays a four-factor structure, as well as evidence of convergent and divergent validity with self-reported aggression and relevant basic (e.g., antagonism, anger) and complex (e.g., psychopathy) personality variables. It is posited that this type of cognitive mechanism may serve as an intermediary link between distal characterological predictors of aggression and its proximal manifestation, which is in line with several prominent theories of personality and may ultimately hold clinical utility by providing a framework for aggression interventions.

Social Influences on Similarity Judgments and Intertemporal Choice

Discounting models are commonly applied to understand intertemporal choices. Similarity models provide an alternative, attribute-based approach where people compare the similarity of reward amounts and time delays for options and decide based on dissimilarity. Knowledge of other people's similarity judgments may affect an individual's similarity judgments, which can in turn affect subsequent intertemporal choices. We investigated the potential effects of social influence across three studies by having participants make similarity judgments and intertemporal choices before and after viewing other people's similarity judgments. We found that participants preferred larger but delayed intertemporal choice options more after they viewed similarity judgments that suggested a preference for larger, later rewards. Additionally, this change in preference seemed to result from a shift in participants' personal similarity judgments for reward amount and time delay pairs to match the social information. Our findings suggest that social information about similarity judgments can shape intertemporal choices, which can potentially be used to help increase people's preferences for options that benefit them in the long term.

Utility of the 5-trial adjusting delay task in screening for high delay discounting rates: A cohort study of individuals reporting harmful alcohol and tobacco use

High delay discounting (DD) rates are associated with several health conditions, including addiction. Investigators interested in the modulation of DD rates may be interested in screening for individuals with high DD rates within substance-using samples. The adjusting delay discounting task (ADT) is a brief DD rate measure suitable for screening purposes, but how performance on this task is related to more granular DD measures (e.g., adjusting amount task; AAT) in individuals who use substances is unknown. This study investigated the relationship between DD rates measured by the ADT and AAT to assess the utility of the ADT in screening for high discounting rates in individuals who use tobacco and alcohol. Participants (N = 488) were screened for high discounting rates, ln(k) ≥ -4.3118, using the ADT. Subsequently, participants completed the AAT. Linear regressions were conducted to understand the relationship between the ADT and AAT DD rates. Separate analyses between the total, high-quality and low-quality samples were conducted. Significant relationships between the ADT and AAT were found for the total (p < .001), high-quality (p < .001), and low-quality samples (p < .001). Although the ADT overestimated DD rates on the AAT by 2.49, 2.29, and 2.97 units in the total, high-quality, and low-quality samples, the ADT accurately identified individuals with high discounting rates. Specifically, 71% of the total sample, 80% of the high-quality sample, and 66% of the low-quality sample maintained a high DD rate on the AAT. These results demonstrate that ADT can be used as a quick, accurate screening tool to identify high discounting rates in individuals who use substances. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effects of short-term nicotine deprivation on delay discounting among young, experienced, exclusive ENDS users: An initial study

Delay discounting describes how rapidly delayed rewards lose value as a function of delay and serves as one measure of impulsive decision-making. Nicotine deprivation among combustible cigarette smokers can increase delay discounting. We aimed to explore changes in discounting following nicotine deprivation among electronic nicotine delivery systems (ENDS) users. Thirty young adults (aged 18-24 years) that exclusively used ENDS participated in two laboratory sessions: one with vaping as usual and another after 16 hr of nicotine deprivation (biochemically assessed). At each session, participants completed a craving measure and three hypothetical delay discounting tasks presenting choices between small, immediate rewards and large, delayed ones (money-money; e-liquid-e-liquid; e-liquid-money). Craving for ENDS significantly increased during short-term nicotine deprivation relative to normal vaping. Delay discounting rates in the e-liquid now versus money later task increased (indicating a shift in preference for smaller, immediate rewards) following short-term nicotine deprivation relative to vaping as usual, but no changes were observed in the other two discounting tasks. Short-term nicotine deprivation increased the preference for smaller amounts of e-liquid delivered immediately over larger, monetary awards available after a delay in this first study of its kind. As similar preference shifts for drug now versus money later have been shown to be indicative of increased desire to use drug as well as relapse risk, the findings support the utility of the current model as a platform to explore interventions that can mitigate these preference shifts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Delay Discounting for HIV/STI Testing

Introduction

Wait time in healthcare is an important barrier to HIV/STI testing. Using a delay discounting approach, the current study examined a systematic reduction in testing likelihood as a function of delay (wait time) until testing.

Methods

In Study 1 (N = 421; data collected in 2019), participants were randomly assigned to either a chlamydia/gonorrhea group or HIV group. A delay discounting task asked them to report how likely they would get tested for the assigned STI if they had to wait for the test (the delay durations varied within persons). In Study 2 (N = 392; data collected in 2020), we added a smaller, sooner outcome (consultation without testing) and tested whether the effect of delay was mediated by perceived severity of the STIs.

Results

In both studies, the subjective value of a delayed STI test was discounted. That is, people were less likely to undergo STI testing as the delay to STI testing increased. The chlamydia/gonorrhea group discounted delayed testing more than the HIV group (i.e., the effect of delay on testing decisions was stronger for the former). This effect was statistically mediated by perceived severity.

Conclusions

We found evidence for delay discounting for HIV/STI testing and that testing decisions were more susceptible to delay when the test was for relatively mild STIs.

Policy Implications

Even mild STIs can cause serious health damage if left untreated. The findings provide strong argument for policies aimed to reduce wait times in healthcare, especially for relatively mild STIs.

Information, ingestion, and impulsivity: The impact of technology-enabled healthy food labels on online grocery shopping in impulsive and non-impulsive consumers

Introduction

Unhealthy food consumption is a problem for society, companies, and consumers. This study aims to contribute to knowledge regarding such issues by investigating how technology-enabled healthy food labels can impact food choice in an online grocery store context. We conceptualized unhealthy and healthy food choice as a matter of impulsivity problems. Three technology-enabled healthy food labels were derived based on variables that might impact self-control, and their influence on food choice was investigated.

Methods

The empirical study consisted of three parts. In the first part, participants’ impulsivity was measured using an adjusting delay task. Part two investigated the effects of self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels on food choice in a hypothetical online grocery shopping setting using a choice-based conjoint experiment. Lastly, in the third part, three where demographical questions were asked.

Results

The results (n = 405) show that self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels had the most to least impact on food choice in that order. Furthermore, the results indicate that self-monitoring and pre-commitment labels had more impact on the choice for impulsive compared to non-impulsive participants. Similarly, the results indicate that social comparison had more impact on choice for non-impulsive participants. These findings suggest that self-monitoring of previous healthy food choices might be more effective than pre-commitment based on discounts for healthy food products. However, these differences were minor.

Discussion

This finding has managerial implications as grocery stores might increase their revenue by introducing self-monitoring labels in an online grocery shopping setting. Future research should investigate these technology-enabled healthy food labels in natural food purchase settings.

A contextualized reinforcer pathology approach to addiction

Behavioural economic accounts of addiction conceptualize harmful drug use as an operant reinforcer pathology, emphasizing that a drug is consumed because of overvaluation of smaller immediate rewards relative to larger delayed rewards (delay discounting) and high drug reinforcing value (drug demand). These motivational processes are within-individual determinants of behaviour. A third element of learning theory posits that harmful drug use depends on the relative constraints on access to other available activities and commodities in the choice context (alternative reinforcers), reflecting the substantial influence of environmental factors. In this Perspective, we integrate alternative reinforcers into the contemporary behavioural economic account of harmful drug use - the contextualized reinforcer pathology model - and review empirical literature across the translational spectrum in support of this model. Furthermore, we consider how increases in drug-related mortality and health disparities in addiction can be understood and potentially ameliorated via a contextualized reinforcer pathology model in which lack of alternative reinforcement is a major risk factor for addiction.

Individual differences in degree of discounting, Do different procedures and measures assess the same construct?

The present study compared the two most prominent procedures for measuring delay discounting, the Adjusting-Amount procedure and the Monetary Choice Questionnaire (MCQ). Of interest was whether the two procedures measure the same construct. Results obtained from two online samples recruited using the Prolific (N = 150) and MTurk (N = 243) platforms revealed generally similar results for both procedures. Regardless of the procedure, the sample, the reward amount, and whether the discounting measure used was theoretically based (i.e., log k) or was atheoretical (i.e., area under the curve, proportion of choices of the delayed reward option), the degree of discounting on the Adjusting-Amount procedure was highly correlated with the degree of discounting on the MCQ, consistent with the hypothesis that both procedures assess the same construct.

Discounting money and health effects from communicable and noncommunicable diseases in Thailand

The purpose of this study was to determine the discount rates for money and health outcomes in the Thai context, including the discount rates for communicable and non-communicable diseases. Moreover, this study aimed to explore the socio-demographic characteristics that influence discounting. The computer-based experimental design was used to obtain time preferences for money and health in a total of 1202 Chiang Mai province population, aged 25-50, individually interviewed by trained interviewers. Money-related questions were carried out in all subjects. For health-related questions, all subjects were randomly assigned in a 1:1 ratio for response to questions about Coronavirus Disease 2019 (COVID-19) (N = 602) and air pollution (N = 600). A choice-based elicitation procedure was performed in the experiment to obtain the indifference values from subjects' time preferences. The cumulative weighting functions were generated using the indifference values to indicate the degree of discounting. The discount factors were computed from the cumulative weighting functions. The discount rates were estimated using a continuous approximation based on the relationship between the discount factors and the parameters governing the discounting model. The Tobit model was applied to investigate the relationships between discounting and socio-demographic characteristics. Discounting for money was greater than discounting for health. Money and health had annual discount rates of 6.2% and 1.3%, respectively. Furthermore, in the COVID -19 situation, the annual discount rate for health was higher than that in the air pollution situation (2.4% vs. 0.7%). Generation X subjects (aged 42 years and above), children under the age of 15 in the household, and underlying diseases were positively related to discounting, while household income was negatively related to discounting. Health should be discounted at a lower rate than money. Moreover, different discount rates should be considered for different types of diseases.

Moderate Stability among Delay, Probability, and Effort Discounting in Humans

The stability of delay discounting across time has been well-established. However, limited research has examined the stability of probability discounting, and no studies of the stability of effort discounting are available. The present study assessed the steady-state characteristics of delay, probability, and effort discounting tasks across time with hypothetical rewards in humans, as well as whether response characteristics suggested a common discounting equation. Participants completed delay, probability, and effort discounting tasks on three occasions. We found moderate relative stability of delay and probability tasks, and similar evidence for absolute stability across time for all tasks. The interclass correlations coefficient showed some correspondence across time points and tasks, and higher levels of between subject variability, especially for the effort discounting task, suggesting trait level variables has a stronger influence on performance than state level variables. Performance on the delay and probability tasks were moderately correlated and similar mathematical functions fit choice patterns on both tasks (hyperbolic), suggesting that delay and probability discounting processes shared some common elements. Lower correlations and different function fits suggested that effort discounting involves more unique features.

Smokers' Affective Responses to COVID-19-Related Health Warnings on Cigarette Packets: The Influence of Delay Discounting

INTRODUCTION

The addition of graphic health warnings to cigarette packets can facilitate smoking cessation, primarily through their ability to elicit a negative affective response. Smoking has been linked to COVID-19 mortality, thus making it likely to elicit a strong affective response in smokers. COVID-19-related health warnings (C19HW) may therefore enhance graphic health warnings compared to traditional health warnings (THW). Further, because impulsivity influences smoking behaviors, we also examined whether these affective responses were associated with delay discounting.

METHODS

In a between-subjects design, 240 smokers rated the valence and arousal elicited by tobacco packaging that contained either a C19HW or THW (both referring to death). Participants also completed questionnaires to quantify delay discounting, and attitudes towards COVID-19 and smoking (eg, health risks, motivation to quit).

RESULTS

There were no differences between the two health warning types on either valence or arousal, nor any secondary outcome variables. There was, however, a significant interaction between health warning type and delay discounting on arousal ratings. Specifically, in smokers who exhibit low delay discounting, C19HWs elicited significantly greater subjective arousal rating than did THWs, whereas there was no significant effect of health warning type on arousal in smokers who exhibited high delay discounting.

CONCLUSION

The results suggest that in smokers who exhibit low impulsivity (but not high impulsivity) C19HWs may be more arousing than THWs. Future work is required to explore the long-term utility of C19HWs, and to identify the specific mechanism by which delay discounting moderates the efficacy of tobacco health warnings.

IMPLICATIONS

The study is the first to explore the impact of COVID-19-related health warnings on cigarette packaging. The results suggest that COVID-19-related warnings elicit a similar level of negative emotional arousal, relative to traditional warnings. However, COVID-19 warnings, specifically, elicit especially strong emotional responses in less impulsive smokers, who report low delay discounting. Therefore, there is preliminary evidence supporting COVID-19 related warnings for tobacco products to aid smoking cessation. Additionally, there is novel evidence that, for some warnings, high impulsiveness may be a factor in reduced warning efficacy, which may explain poorer cessation success in this population.

Sooner is Better: Longitudinal Relations Between Delay Discounting, and Depression and Anxiety Symptoms among Vietnamese Adolescents

Delay discounting refers to the decline in the present value of an outcome as a function of the delay to its receipt. Research on delay discounting initially focused on substance abuse, generally finding that greater delay discounting is associated with increased risk for and severity of substance abuse. More recently, delay discounting has been linked theoretically and empirically to affective psychopathology, potentially suggesting novel intervention targets for mental health problems such as depression and anxiety. Longitudinal research consequently is critical to determine direction of causality and rule out possible third variable explanations. Only a small number of longitudinal studies have been conducted in this area, however. Furthermore, socio-economic and socio-cultural factors may influence delay discounting and its effects, but thus far the literature is relatively limited in this regard. The present study focused on adolescence, a key time-period for development of delay discounting and emotional problems. Longitudinal relations between delay discounting, and depression and anxiety symptoms were assessed among 414 adolescents in Vietnam, a lower-middle-income Southeast Asian nation with significant cultural divergence from Western countries. In contrast to most cross-sectional studies that have found positive or non-significant correlations, in the present study delay discounting at Time 1 had a negative beta with anxiety and depression symptoms at Time 1, with preference for immediate but smaller rewards (higher discounting) at Time 1 associated with lower anxiety and depression symptoms at Time 2. These results suggest that under certain circumstances, steeper delay discounting may be adaptive and supportive of emotional mental health.

Developmental trajectories of delay discounting from childhood to young adulthood: longitudinal associations and test-retest reliability

Delay discounting (DD) indexes an individual's preference for smaller immediate rewards over larger delayed rewards, and is considered a form of cognitive impulsivity. Cross-sectional studies have demonstrated that DD peaks in adolescence; longitudinal studies are needed to validate this putative developmental trend, and to determine whether DD assesses a temporary state, or reflects a more stable behavioral trait. In this study, 140 individuals aged 9-23 completed a delay discounting (DD) task and cognitive battery at baseline and every-two years thereafter, yielding five assessments over approximately 10 years. Models fit with the inverse effect of age best approximated the longitudinal trajectory of two DD measures, hyperbolic discounting (log[k]) and area under the indifference-point curve (AUC). Discounting of future rewards increased rapidly from childhood to adolescence and appeared to plateau in late adolescence for both models of DD. Participants with greater verbal intelligence and working memory displayed reduced DD across the duration of the study, suggesting a functional interrelationship between these domains and DD from early adolescence to adulthood. Furthermore, AUC demonstrated good to excellent reliability across assessment points that was superior to log(k), with both measures demonstrating acceptable stability once participants reached late adolescence. The developmental trajectories of DD we observed from childhood through young adulthood suggest that DD may index cognitive control more than reward sensitivity, and that despite modest developmental changes with maturation, AUC may be conceptualized as a trait variable related to cognitive control vs impulsivity.

Fronto-striatal connectivity patterns account for the impact of methylphenidate on choice impulsivity among healthy adults

Choice impulsivity depicts a preference towards smaller-sooner rewards over larger-delayed rewards, and is often assessed using a delay discounting (DD) task. Previous research uncovered the prominent role of dopaminergic signaling within fronto-striatal circuits in mediating choice impulsivity. Administration of methylphenidate (MPH), an indirect dopaminergic agonist, was shown to reduce choice impulsivity in animals and pathological populations, although significant inter-individual variability in these effects was reported. Whether MPH impacts choice impulsivity among healthy individuals, and whether variability in the impact of MPH is related to fronto-striatal activation and connectivity patterns, has yet to be assessed. Here, fifty-seven healthy young adults completed the DD task twice during fMRI scans, after acute administration of either MPH (20 mg) or placebo, in a randomized double-blind placebo-controlled design. Acute MPH administration was found to reduce choice impulsivity at the group level, yet substantial variability in this behavioral response was observed. MPH was also found to increase activation in the bilateral putamen and the right caudate, and to enhance functional connectivity between the left putamen and medial prefrontal cortex (mPFC), particularly during non-impulsive choices. Notably, the more putamen-mPFC functional connectivity increased during non-impulsive choices following MPH administration, the less an individual was likely to make impulsive choices. These findings reveal, for the first time in healthy adults, that acute MPH administration is associated with reduced choice impulsivity and increased striatal activation and fronto-striatal connectivity; and furthermore, that the magnitude of MPH-induced change in fronto-striatal connectivity may account for individual differences in the impact of MPH on impulsive behavior.

Delay discounting of money and health outcomes, and adherence to policy guidelines during the COVID-19 pandemic

Delay discounting refers to the observation that the subjective value of an outcome decreases as the delay to its receipt increases. It is well-established that steep delay discounting is related to various maladaptive behaviors, including poorer health-related choices. One of the current challenges of public health policies that emerged during the COVID-19 pandemic is to encourage preventive behaviors against infectious diseases. In this study, we aimed to explore possible underpinnings of adherence to COVID-19 related public health policy guidelines such as disinfection, distancing, and masks (DDM). Participants completed monetary and health discounting tasks across two outcome amounts in gain and loss conditions, and they provided self-report measures of adherence to the DDM policy. Contrary to the theoretically plausible prediction that higher discounting rates would be negatively associated with adherence to health-related public policy guidelines, we found no compelling evidence to support such statement. We discuss the potential weaknesses of declarative measurements of attitudes toward COVID-19 and consider using behavioral interventions for influencing discounting rates for complementing and enhancing current policy guidelines.

Expectations of immediate and delayed reward differentially affect cognitive task performance

The current study used a modified Monetary Incentive Delay task to examine the neural mechanisms underlying anticipating and receiving an immediate or delayed reward and examined the influence of pursuing these rewards on cognitive task performance. A pre-cue indicating the potential of gaining a monetary reward (immediate-, delayed-, vs. no-reward) was followed by a target stimulus requiring a fast and accurate response. Then, response-contingent feedback was presented indicating whether or not the participant would receive the corresponding reward. Linear mixed-effect models revealed the fastest behavioural responses and the strongest neural activity, as reflected in event-related-potentials and event-related-spectral-perturbation responses, for immediate reward, followed by delayed reward, with the slowest behavioural responses and the weakest neural activities observed in the no-reward condition. Expectations related to the cue-P3 component and the cue-delta activities predicted behavioural performance, especially in the immediate reward condition. Moreover, exploratory analyses revealed that depression moderated the relationship between target-locked neural activity and behavioural performance in the delayed reward condition, with lower neural activity being related to worse behavioural performance amongst participants scoring high on depression. These results indicate that differential value representations formed through delay discounting directly affect neural responses in reward processing and directly influence the effort invested in the current task, which is reflected by behavioural responses and is in agreement with the expected value of control theory.

One-year into COVID-19 pandemic: Decision-making and mental-health outcomes and their risk factors

BACKGROUND

The COVID-19 pandemic represents an unprecedented worldwide crisis with serious socioeconomic, physical and mental health consequences. However, its long-lasting effects on both mental health and decision-making difficulties remain unexplored. This study aimed to determine the prevalence and severity of psychological disorders in Italy's populace one-year after the outbreak; further, we investigated potential risks impacting mental health and decision-making.

METHODS

In March 2021, 586 individuals (18-73 years) completed an online-survey plus a computerized delay discounting task for hypothetical money rewards.

RESULTS

Psychological symptoms prevalence exceeded the Italy's lockdown rates, with about one-third reporting moderate-to-extremely severe depression, another third anxiety, and the rest stress; mirrored by an increase of symptoms at clinically significant severity levels. One year into the pandemic, half of our sample presented at least one psychological problem, and one-third was at risk of developing a more clinically severe psychological outcome. Fear of job loss, loneliness and intolerance of uncertainty were among the major risk factors to mental health. Plus, social-relationships and financial uncertainty were key determinants of depression, while fear of COVID-19 infection predicted anxiety symptoms. For decision-making tendencies, elevated delay discounting rates, implying less future-oriented behaviors, were mostly predicted by increased job loss fear and older age (>35 years).

LIMITATIONS

This study provides cross-sectional evidence.

CONCLUSIONS

Depression, anxiety and stress levels were still alarming one-year into COVID-19. Individuals experiencing financial insecurity, loneliness and intolerance of uncertainty perhaps benefit most from early interventions. Governments need to implement timely recovery plans to reduce financial insecurity, given its significant mental health impact and decision-making outcomes.