The perceived controllability of negatively-valenced episodic future thinking modulates delay discounting.

Intertemporal decision-making is important for both economy and physical health. Nevertheless, in daily life, individuals tend to prefer immediate and smaller rewards to delayed and larger rewards, which is known as delay discounting (DD). Episodic future thinking (EFT) has been proven to influence DD. However, there is still no inconsistent conclusion on the effect of negative EFT on DD. Considering the perceived controllability of negative EFT may address the issue (Controllability refers to the extent to which progress and result of an event could be controlled by ourselves). In the current study, we manipulated EFT conditions (baseline, neutral EFT, negative-controllable EFT and negative-uncontrollable EFT), delayed time (i.e. 1 week, 1 month, 3 months, 6 months, 1 year and 3 years) and reward magnitude (small, large). We mainly found that when experiencing negative-uncontrollable EFT compared to negative-controllable EFT in the delayed time of 6 months with large rewards, individuals chose more delayed rewards, suggesting that negative-uncontrollable EFT effectively reduced DD under conditions of both large-magnitude reward and longer delayed time. The current study provides new insight for healthy groups on optimising EFT. In that case, individuals are able to gain long-term benefits in financial management and healthcare.

Inconsistent advice by ChatGPT influences decision making in various areas.

The ChatGPT technology is increasingly becoming a part of our daily lives and is starting to be utilized in various decision-making contexts. The current study builds upon prior research, demonstrating that people's moral decision-making is influenced by ChatGPT across three perspectives, as evidenced by two studies (total n = 1925). The findings suggested that ChatGPT advice impacted decision-making similarly to expert advice, although not all decisions were susceptible to influence, particularly those based on negative emotions. Additionally, ChatGPT advice affected decisions beyond moral judgments, but no effect was observed when the advice recommended immediate low rewards. Moreover, individuals with a higher tendency for personal fear of invalidity were more likely to be influenced by both expert and AI advice, but this was not related to trust in AI.

Environmental Support Moderates the association of Socioeconomic Distress and Delay Discounting across Adolescence.

Early exposure to socioeconomic distress is hypothesized to reinforce decision making that prioritizes immediate, relative to delayed, rewards (i.e., delay discounting); yet these relations have not been examined longitudinal across the vulnerable adolescent period. This study is one of the first to utilize objective and subjective measures to evaluate the relative effects of environmental disadvantage and the potential protective effects of perceived environmental support on delay discounting. A diverse (48.4% White; 46.7% female) sample of participants (N = 246) reported on their home addresses at baseline when they were, on average, 11.96 years old (SDage = 0.88); Youth then reported perceived environmental supports at baseline and delay discounting annually from ages 13 to 18. A socioeconomic distress index was derived from census tract rates of unemployment, income, educational attainment, and lone parenthood. Greater socioeconomic distress was associated with a greater propensity to discount delayed rewards at baseline. Findings also suggest greater perceived higher environmental support was associated with decreasing rates of delay discounting across adolescence for youth from highly socioeconomically distressed areas. These results highlight potential future avenues for preventative and intervention efforts to improve positive youth outcomes.

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.

No effects of acute stress on monetary delay discounting: A systematic literature review and meta-analysis.

Many everyday decisions, including those concerning our health, finances and the environment, involve choosing between a smaller but imminent reward (e.g., €20 now) and a later but larger reward (e.g., €40 in a month). The extent to which an individual prefers smaller imminent rewards over larger delayed rewards can be measured using delay discounting tasks. Acute stress induces a cascade of biological and psychological responses with potential consequences for how individuals think about the future, process rewards, and make decisions, all of which can impact delay discounting. Several studies have shown that individuals focus more on imminent rewards under stress. These findings have been used to explain why individuals make detrimental choices under acute stress. Yet, the evidence linking acute stress to delay discounting is equivocal. To address this uncertainty, we conducted a meta-analysis of 11 studies (14 effects) to systematically quantify the effects of acute stress on monetary delay discounting. Overall, we find no effect of acute stress on delay discounting, compared to control conditions (SMD = -0.18, 95% CI [-0.57, 0.20], p = 0.32). We also find that neither the gender/sex of the participants, the type of stressor (e.g., physical vs. psychosocial) nor whether monetary decisions were hypothetical or incentivized (i.e. monetary decisions were actually paid out) moderated the impact of acute stress on monetary delay discounting. We argue that establishing the effects of acute stress on the separate processes involved in delay discounting, such as reward valuation and prospection, will help to resolve the inconsistencies in the field.

Effectiveness and feasibility of the self-administered and repeated episodic future thinking exercises in smoking cessation.

Delay discounting (DD) is associated with smoking behavior and relapses. Episodic future thinking (EFT) is one of the leading interventions shown to reduce DD. The 1-month follow-up study with 60 participants that employed EFT as active intervention and episodic recent thinking (ERT) as control intervention was conducted in participants receiving smoking cessation treatment. In EFT group, there was significant decrease in DD rates from pre-intervention to post-intervention (p = 0.009), whereas no significant change was observed in ERT group (p = 0.497). DD rates in EFT group did not change significantly over 1 month (p = 0.059), while decrease was detected in ERT group (p = 0.011). Smoking cessation rates between groups were similar (p = 0.486). Adherence with completing follow-up evaluation forms and performing relevant exercises was higher in EFT group (p = 0.038, p = 0.006). Adding EFT to usual smoking cessation treatment did not increase smoking cessation rates, however feasibility of the self-administered exercises needs to be improved to clarify clinical effects.

Differential phase-amplitude coupling in nucleus accumbens and orbitofrontal cortex reflects decision-making during a delay discounting task.

BACKGROUND: The impulsive choice is characterized by the preference for a small immediate reward over a bigger delayed one. The mechanisms underlying impulsive choices are linked to the activity in the Nucleus Accumbens (NAc), the orbitofrontal cortex (OFC), and the dorsolateral striatum (DLS). While the study of functional connectivity between brain areas has been key to understanding a variety of cognitive processes, it remains unclear whether functional connectivity differentiates impulsive-control decisions. METHODS: To study the functional connectivity both between and within NAc, OFC, and DLS during a delay discounting task, we concurrently recorded local field potential in NAc, OFC, and DLS in rats. We then quantified the degree of phase-amplitude coupling (PAC), coherence, and Granger Causality between oscillatory activities in animals exhibiting either a high (HI) or low (LI) tendency for impulsive choices. RESULTS: Our results showed a differential pattern of PAC during decision-making in OFC and NAc, but not in DLS. While theta-gamma PAC in OFC was associated with self-control decisions, a higher delta-gamma PAC in both OFC and NAc biased decisions toward impulsive choices in both HI and LI groups. Furthermore, during the reward event, Granger Causality analysis indicated a stronger NAc➔OFC gamma contribution in the HI group, while the LI group showed a higher OFC➔NAc gamma contribution. CONCLUSIONS: The overactivity in NAc during reward in the HI group suggests that exacerbated contribution of NAcCore can lead to an overvaluation of reward that biases the behavior toward the impulsive choice.

Neuropharmacology involvement of dopamine D3 receptor in impulsive choice decision-making in male rats.

Impulsive decision-making has been linked to impulse control disorders and substance use disorders. However, the neural mechanisms underlying impulsive choice are not fully understood. While previous PET imaging and autoradiography studies have shown involvement of dopamine and D2/3 receptors in impulsive behavior, the roles of distinct D1, D2, and D3 receptors in impulsive decision-making remain unclear. In this study, we used a food reward delay-discounting task (DDT) to identify low- and high-impulsive rats, in which low-impulsive rats exhibited preference for large delayed reward over small immediate rewards, while high-impulsive rats showed the opposite preference. We then examined D1, D2, and D3 receptor gene expression using RNAscope in situ hybridization assays. We found that high-impulsive male rats exhibited lower levels of D2 and D3, and particularly D3, receptor expression in the nucleus accumbens (NAc), with no significant changes in the insular, prelimbic, and infralimbic cortices. Based on these findings, we further explored the role of the D3 receptor in impulsive decision-making. Systemic administration of a selective D3 receptor agonist (FOB02-04) significantly reduced impulsive choices in high-impulsive rats but had no effects in low-impulsive rats. Conversely, a selective D3 receptor antagonist (VK4-116) produced increased both impulsive and omission choices in both groups of rats. These findings suggest that impulsive decision-making is associated with a reduction in D3 receptor expression in the NAc. Selective D3 receptor agonists, but not antagonists, may hold therapeutic potentials for mitigating impulsivity in high-impulsive subjects.

Differential signaling effects of blood glucose on delay discounting in individuals with and without type 1 diabetes.

Based on the signaling hypothesis of blood glucose (BG), a rise in BG levels signals a positive energy budget for healthy individuals but cellular starvation for individuals with type 1 diabetes. We examined this novel prediction and its intervention implications in the context of delay discounting, the degree to which delayed rewards are discounted, and the regulatory effects of insulin ingestion. We recruited 44 adults with type 1 diabetes (mean age 30.8 years, diabetes duration 15.4 years) and recorded their BG levels. The delay discounting rate was measured using the intertemporal choice task, where participants were required to choose between sets of smaller-and-sooner (SS) and larger-and-later (LL) rewards. In addition, 82 age-matched healthy participants were recruited to provide a baseline comparison on delay discounting. Random forest analysis showed that among many diagnostic factors, delay discounting was most dominating in differentiating the individuals with type 1 diabetes from the control participants. A hierarchical linear mixed model revealed that participants with type 1 diabetes had a stronger preference for SS rewards (p < .001) after controlling for covariates. Participants who had insulin delivered before the last meal exhibited a stronger preference for LL rewards compared to after-meal delivery. In contrast, subjective measures (e.g., self-reported hunger) failed to predict the participants' actual BG levels and delay discounting rates. In sum, individuals with type 1 diabetes tend to discount future rewards excessively compared to the control participants. Pre-meal insulin ingestion was associated with a higher LL preference for future rewards.

Low-Level Visual Features of Window Views Contribute to Perceived Naturalness and Mental Health Outcomes.

Previous studies have shown that natural window views are beneficial for mental health, but it is still unclear which specific features constitute a 'natural' window view. On the other hand, studies on image analysis found that low-level visual features (LLVFs) are associated with perceived naturalness, but mainly conducted experiments with brief stimulus presentations. In this study, research on the effects of window views on mental health was combined with the detailed analysis of LLVFs. Healthy adults rated window views from their home and sent in photographs of those views for analysis. Content validity of the 'ecological' view assessment was evaluated by checking correlations of LLVFs with window view ratings. Afterwards, it was explored which of the LLVFs best explained variance in perceived percentage of nature and man-made elements, and in ratings of view quality. Criterion validity was tested by investigating which variables were associated with negative affect and impulsive decision-making. The objective and subjective assessments of nature/sky in the view were aligned but objective brightness was unreliable. The perceived percentage of nature was significantly explained by green pixel ratio, while view quality was associated with fractals, saturation, sky pixel ratio and straight edge density. The higher subjective brightness of rooms was associated with a lower negative affect, whereas results for impulsive decision-making were inconsistent. The research highlights the validity to apply LLVFs analysis to ecological window views. For affect, subjective brightness seemed to be more relevant than LLVFs. For impulsive decision-making, performance context needs to be controlled in future studies.

Hyperbolae.

Hyperbolic relations between independent and dependent variables are ubiquitous in the experimental analysis of behavior, mentioned in over 150 articles in the Journal of the Experimental Analysis of Behavior. There are two principal forms of hyperbolae: The first describes the relation between response rate and reinforcement rate on variable-interval schedules of reinforcement; it rises asymptotically toward a maximum. The second describes the relation between the current equivalent value of an incentive and its delay or (im)probability; it falls from a maximum toward an asymptote of 0. Where do these come from? What do their parameters mean? How are they related? This article answers the first two questions and addresses the last.

Effects of delay sequence in a delay discounting task.

Delay discounting refers to the decrease in subjective value of a reward as the delay until its receipt increases. In the present study we assessed the effects of the sequence of delay blocks (increasing or decreasing) on discounting and the data systematicity using a titrating procedure with human participants. All participants completed the delay discounting task in both an increasing and decreasing sequence of delays. Delays ranged from one day to ten years. We found steeper discounting when the delays were presented in an increasing sequence compared with when they were presented in a decreasing sequence. We also found steeper discounting when participants completed the increasing sequence condition first. Our results agree with other findings reported in the literature and suggest that delay discounting may be affected by prior and subsequent experience.

Longitudinal Associations Among Socioeconomic Status, Delay Discounting, and Substance Use in Adolescence.

It is unclear how delay discounting and substance use develop across adolescence and whether contextual factors alter their trajectories. The present study used a longitudinal design to examine whether socioeconomic status is related to developmental trajectories of delay discounting and substance use across adolescence. The sample included 167 adolescents (Mage = 14 at Time 1; 53% male) and their parents who participated annually across four years. Parents reported SES at Time 1 and adolescents completed delay discounting behavioral assessments and substance use questionnaires at Times 1 to 4. Bivariate latent growth curve modeling revealed that low SES was related to steeper increases in substance use from age 14 through 17, mediated through elevated delay discounting at age 14. The findings clarify the mediating role of delay discounting in linking family economic environment to the progression of substance use.

Developmental exposure to 17-α-hydroxyprogesterone caproate disrupts decision-making in adult female rats: A potential role for a dopaminergic mechanism.

The synthetic progestin, 17α-hydroxyprogesterone caproate (17-OHPC), is administered to pregnant individuals at risk for preterm birth and is likely transferred from mother to fetus. Yet, there is little information regarding the potential effects of 17-OHPC administration on behavioral and neural development in offspring. In rats, neonatal 17-OHPC exposure altered dopaminergic fiber distribution and density in the prelimbic medial prefrontal cortex (mPFC) in neonates and adolescents, respectively. Additionally, neonatal 17-OHPC exposure in male rats increased response omissions in a delay discounting task of impulsive decision-making. Because developmental 17-OHPC exposure has differential effects in males and females, investigating the effects of 17-OHPC on impulsive decision-making in female rats is necessary. The present study tested the effects of developmental 17-OHPC exposure (P1-P14) in a delay discounting task in which female rats chose between a small immediate reward and a larger delayed (0, 15 30, or 45 s) reward. 17-OHPC-exposed females made more omissions than controls. There was no effect of 17-OHPC on large reward preference nor on response time, and omissions were similar during both free- and forced-choice trials. The present study also aimed to investigate the neural mechanisms underlying omissions in 17-OHPC-exposed female rats. The dopamine transporter inhibitor, methylphenidate (MPH), was administered prior to delay discounting testing. MPH treatment did not reduce omissions in 17-OHPC-exposed females. If anything, MPH increased omissions in control females nearly fourfold during the longest delays. These results suggest that developmental 17-OHPC exposure increased omissions without affecting impulsivity or slowing decision-making. Furthermore, omissions may be regulated, at least in part, by dopaminergic mechanisms.

Perceptions and effectiveness of episodic future thinking as digital micro-interventions based on mobile health technology.

Objective: Delay discounting denotes the tendency for humans to favor short-term immediate benefits over long-term future benefits. Episodic future thinking (EFT) is an intervention that addresses this tendency by having a person mentally "pre-experience" a future event to increase the perceived value of future benefits. This study explores the feasibility of using mobile health (mHealth) technology to deliver EFT micro-interventions. Micro-interventions are small, focused interventions aiming to achieve goals while matching users' often limited willingness or capacity to engage with interventions. We aim to explore whether EFT delivered as digital micro-interventions can reduce delay discounting, the users' perceptions, and if there are differences between regular EFT and goal-oriented EFT (gEFT), a variant where goals are embedded into future events. Method: A randomized study was conducted with 208 participants allocated to either gEFT, EFT, or a control group for a 21-day study. Results: Results indicate intervention groups when combined achieved a significant reduction of Δlogk=-.80 in delay discounting (p=.017) compared to the control. When split into gEFT and EFT separately only the reduction of Δlogk=.96 in EFT delay discounting was significant (p=.045). We further explore and discuss thematic user perceptions. Conclusions: Overall, user perceptions indicate gEFT may be slightly better for use in micro-interventions. However, perceptions also indicate that audio-based EFT micro-interventions were not always preferable to users, with findings suggesting that future EFT micro-interventions should be delivered using different forms of multimedia based on user preference and context and supported by other micro-interventions to maintain interest.

Psychometric properties of the Chinese version of the Quick Delay Questionnaire (C-QDQ) and ecological characteristics of reward-delay impulsivity of adults with ADHD.

BACKGROUND: The Quick Delay Questionnaire (QDQ) is a short questionnaire designed to assess delay-related difficulties in adults. This study aimed to examine the reliability and validity of the Chinese version of the QDQ (C-QDQ) in Chinese adults, and explore the ecological characteristics of delay-related impulsivity in Chinese adults with attention-deficit/hyperactivity disorder (ADHD). METHODS: Data was collected from 302 adults, including ADHD (n = 209) and healthy controls (HCs) (n = 93). All participants completed the C-QDQ. The convergent validity, internal consistency, retest reliability and confirmatory factor analysis (CFA) of the C-QDQ were analyzed. The correlations between C-QDQ and two laboratory measures of delay-related difficulties and Barratt Impulsiveness Scale-11 (BIS-11), the comparison of C-QDQ scores between ADHD subgroups and HCs were also analyzed. RESULTS: The Cronbach's α of C-QDQ was between 0.83 and 0.89. The intraclass correlation coefficient of C-QDQ was between 0.80 and 0.83. The results of CFA of C-QDQ favoured the original two-factor model (delay aversion and delay discounting). Significant positive associations were found between C-QDQ scores and BIS-11 total score and performance on the laboratory measure of delay-related difficulties. Participants with ADHD had higher C-QDQ scores than HCs, and female ADHD reported higher scores on delay discounting subscale than male. ADHD-combined type (ADHD-C) reported higher scores on delay aversion subscale than ADHD-inattention type (ADHD-I). CONCLUSION: The C-QDQ is a valid and reliable tool to measure delay-related responses that appears to have clinical utility. It can present the delay-related impulsivity of patients with ADHD. Compared to HCs, the level of reward-delay impulsivity was higher in ADHD.

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.

Delay discounting is associated with addiction and mental health measures while controlling for health behaviors and health barriers in a large US sample.

Background: Excessive discounting of future rewards [delay discounting (DD)] may be a transdiagnostic process and treatment target underlying behavioral health outcomes, including trauma, depression, anxiety, and problematic substance use. However, multiple health behaviors and barriers are also related to these outcomes, including social media usage, adverse childhood experiences (ACEs), sleep quality, healthcare access, housing status, and exercise. To extend research examining DD as transdiagnostic process, we recruited a large, heterogenous sample to examine the association between DD, problematic substance use, and mental health outcomes while controlling for certain health behaviors and health barriers. Method: In a cross-sectional online survey of 3992 US residents, we administered validated measures of PTSD, depression, anxiety, and problematic alcohol, stimulant, and opioid use. Using linear or ordinal logistic models, scores for each outcome were regressed onto DD while controlling for demographics, health behaviors, and health barriers. Results: Including only DD and demographics, DD was associated with each outcome at low effect sizes (ƒ2 = .013, OR range = 1.08-1.16). Except for opioid ASSIST scores, these relationships held when controlling for social media usage, sleep, housing status, healthcare access, ACEs, physical exercise, and demographic variables (ƒ2 = .002, OR range = 1.03-1.12), increasing confidence that DD concurrently and directly relates to four of these five clinical outcomes. Discussion: These findings support the conceptualization of DD as a transdiagnostic process underlying certain psychopathologies and suggest targeting DD in co-occurring substance use disorder and/or mental health treatments may result in clinically significant outcomes.

Examining the association between delay discounting, delay aversion and physical activity in Chinese adults with type-2 diabetes mellitus.

BACKGROUND: The role of physical activity in diabetes is critical, influencing this disease's development, man-agement, and overall outcomes. In China, 22.3% of adults do not meet the minimum level of physical activity recommended by the World Health Organization. Therefore, it is imperative to identify the factors that contributing to lack of physical activity must be identified. AIM: To investigate the relationship among delay discounting, delay aversion, glycated hemoglobin (HbA1c), and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus (T2DM). METHODS: In 2023, 400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province. A face-to-face questionnaire was used to gather demographic data and details on physical activity, delay discounting, and delay aversion. In addition, HbA1c levels were measured in all 400 participants. The primary independent variables considered were delay discounting and delay aversion. The outcome variables included HbA1c levels and different intensity levels of physical activity, including walking, moderate physical activity, and vigorous physical activity. Multiple linear regression models were utilized to assess the relationship between delay discounting, delay aversion, and HbA1c levels, along with the intensity of different physical activity measured in met-hours per week. RESULTS: After controlling for the sample characteristics, delay discounting was negatively associated with moderate physical activity (ß = -2.386, 95%CI: -4.370 to -0.401). Meanwhile, delay aversion was negatively associated with the level of moderate physical activity (ß = -3.527, 95% CI: -5.578 to -1.476) in the multiple linear regression model, with statistically significant differences. CONCLUSION: Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity. Result suggests that delay discounting and aversion may influence engagement in moderate physical activity. This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM, which may increase participation in physical activity. This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays.

The Impact of Monetary Incentives on Delay Discounting Within a Year-Long Physical Activity Intervention.

BACKGROUND: Delay discounting is the depreciation in a reward's perceived value as a function of the time until receipt. Monetary incentive programs that provide rewards contingent on meeting daily physical activity (PA) goals may change participants' delay discounting preferences. PURPOSE: Determine if monetary incentives provided in close temporal proximity to meeting PA goals changed delay discounting, and if such changes mediated intervention effects. METHODS: Inactive adults (n = 512) wore accelerometers during a 12-month intervention where they received proximal monetary incentives for meeting daily moderate-to-vigorous PA (MVPA) goals or delayed incentives for study participation. Delay discount rate and average MVPA were assessed at baseline, end of intervention, and a 24-month follow-up. Using structural equation modeling, we tested effects of proximal versus delayed rewards on delay discounting and whether any changes mediated intervention effects on MVPA. PA self-efficacy was also evaluated as a potential mediator, and both self-efficacy and delay discounting were assessed as potential moderators of intervention effects. RESULTS: Proximal rewards significantly increased participants' delay discounting (ß = 0.238, confidence interval [CI]: -0.078, 0.380), indicating greater sensitivity to reinforcement timing. This change did not mediate incentive-associated increases in MVPA at the end of the 12-month intervention (ß = -0.016, CI: -0.053, 0.019) or at a 24-month follow-up (ß = -0.020, CI: -0.059, 0.018). Moderation effects were not found. CONCLUSIONS: Incentive-induced increases in delay discounting did not deleteriously impact MVPA. This finding may help assuage concerns about using monetary incentives for PA promotion, but further research regarding the consequences of changes in delay discounting is warranted.

This study examined the effects of providing proximal monetary incentives for meeting daily exercise goals on people's tendency to value immediate versus delayed rewards. Inactive adults (n = 512) participated in a year-long program where they wore an accelerometer each day and received either (i) small monetary rewards in close temporal proximity to instances of meeting daily exercise goals or (ii) larger rewards at 2-month intervals for ongoing participation. Those receiving proximal incentives showed an increased preference for immediate rewards, yet this reported change did not compromise long-term physical activity gains. In a comparison analysis, we found that proximal monetary incentives were not associated with changes in exercise self-efficacy. Overall, the findings suggest that monetary incentives for exercise do not negatively impact people's activity levels, though more research is needed to fully understand the implications of changes in reward timing preferences.