Temporal discounting in choice between delayed rewards: the role of age and income

The effect of executive function on adherence with a cardiac secondary prevention program and its interaction with an incentive-based intervention

Participation in secondary prevention programs such as cardiac rehabilitation (CR) reduces morbidity, mortality, and hospitalizations while improving quality of life. Executive function (EF) is a complex set of cognitive abilities that control and regulate behavior. EF predicts many health-related behaviors, but how EF interacts with interventions to improve treatment adherence is not well understood. The objective of this study is to examine if EF predicts CR treatment adherence and how EF interacts with an intervention to improve adherence. Data were collected from 2013 to 2018 in Vermont, USA. 130 Medicaid-enrolled individuals who had experienced a qualifying cardiac event were enrolled in a controlled clinical trial and randomized 1:1 to receive financial incentives for completing secondary prevention sessions or to usual care. In this secondary analysis, effects of EF on CR adherence (defined as completing ≥30/36 sessions) were examined in 112 participants (57 usual care, 55 intervention) who completed an EF battery. Delay-discounting, a measure of impulsivity, predicted CR adherence (p = 0.01) and interacted with the incentive intervention, such that those who exhibited greater discounting of future rewards benefitted more from the intervention than those who discounted less (F(1, 104) = 5.23, p = 0.02). Better cognitive flexibility, measured with the trail-making-task, also predicted CR adherence (p = 0.02). While EF has been associated with adherence to a variety of treatment regimens, this interaction between an incentive-based intervention to promote treatment adherence and EF is novel. This work illustrates the value of considering individual differences in EF when designing and implementing interventions to promote health-related behavior change.

Neural mechanisms of decision-making in aging

The present review synthesizes findings on decision neuroscience and aging by focusing on decision processes that have been extensively studied in neuroeconomics and critically assessing the driving mechanisms of age-related change. The paper first highlights age-related changes to key brain structures that have been implicated in decision-making, then, reviews specific decision components and discusses investigations of age-related changes to their neural mechanisms. The review also weighs evidence for organic brain aging versus age-related changes to social and psychological factors in mediating age effects. Reviewed findings are discussed in the context of theories and frameworks that have been used to explain trajectories of change in decision-making across adulthood. This article is categorized under: Psychology > Development and Aging Psychology > Reasoning and Decision-Making Neuroscience > Cognition.

Delay discounting and affective priming in individuals with negative schizotypy

Previous studies have demonstrated that patients with schizophrenia and individuals with schizotypy experience decreased anticipatory pleasure. However, it is unclear whether this decrease is contributed by altered reward processing at the proximal or distal future. In order to investigate the preference for receiving rewards in the proximal or distal future for individuals with schizophrenia spectrum disorders, individuals with either high or low levels of negative schizotypy performed a delay discounting task under positive, neutral and negative affective priming conditions. Compared with individuals with low levels of negative schizotypy, individuals with high levels of schizotypy exhibited increased delay discounting, preferring to choose immediate but smaller rewards instead of delayed but larger rewards across all three affective priming conditions. Negative affective priming elevated discounting for both groups compared with both the positive and neutral affective conditions. After dividing delayed temporal distance into the proximal and distal future, the results showed that individuals with high levels of negative schizotypy exhibited more preference for immediate but smaller rewards in the distal instead of proximal future compared with controls. Our results suggest that individuals with high levels of negative schizotypy have altered anticipatory reward processing, which is mainly attributed to alterations in representing rewards in the distal future. These findings extend the alterations in representing reward values from schizophrenia patients to schizotypal individuals, and suggest that diminished anticipatory pleasure in schizophrenia spectrum disorders may be due to changes in processing anticipatory rewards in the distal future.

Development of a Spatial Discount Task to Measure Impulsive Choices in Dogs

Simple Summary

Impulsivity is believed to play a role in problematic behaviors in dogs. In this study, we developed a test to assess dogs’ tendency to make impulsive choices, that is their preference for smaller immediate reward instead of larger, but harder to obtain ones. Dogs were first trained that a bowl presented on a certain side always contained a large food amount, whereas the one presented on the opposite side (although at the same distance from the dog) contained less food. Then, the bowl with less food was progressively placed closer to the dog. As expected, dogs’ choices to feed from the bowl with less food increased as the distance of the latter decreased. Choices did not depend on factors that could interfere, such as dogs’ level of motivation for food, training experience, or learning ability. This indicates that the test is likely to be actually assessing impulsivity, not other traits. Also, female dogs were more likely to make impulsive choices than males, in accordance with what is known in humans and rodents, supporting the validity of the test. The test was completed in less than 1 h, making it a valid option to assess impulsivity in dogs in various contexts.

Abstract

Impulsive choices reflect an individual’s tendency to prefer a smaller immediate reward over a larger delayed one. Here, we have developed a behavioural test which can be easily applied to assess impulsive choices in dogs. Dogs were trained to associate one of two equidistant locations with a larger food amount when a smaller amount was presented in the other location, then the smaller amount was placed systematically closer to the dog. Choices of the smaller amount, as a function of distance, were considered a measure of the dog’s tendency to make impulsive choices. All dogs (N = 48) passed the learning phase and completed the entire assessment in under 1 h. Choice of the smaller food amount increased as this was placed closer to the dog. Choices were independent from food motivation, past training, and speed of learning the training phase; supporting the specificity of the procedure. Females showed a higher probability of making impulsive choices, in agreement with analogue sex differences found in human and rodent studies, and supporting the external validity of our assessment. Overall, the findings support the practical applicability and represent a first indication of the validity of this method, making it suitable for investigations into impulsivity in dogs.

Age-Related Differences in Motivational Integration and Cognitive Control

Motivational incentives play an influential role in value-based decision-making and cognitive control. A compelling hypothesis in the literature suggests that the motivational value of diverse incentives are integrated in the brain into a common currency value signal that influences decision-making and behavior. To investigate whether motivational integration processes change during healthy aging, we tested older (N = 44) and younger (N = 54) adults in an innovative incentive integration task paradigm that establishes dissociable and additive effects of liquid (e.g., juice, neutral, saltwater) and monetary incentives on cognitive task performance. The results reveal that motivational incentives improve cognitive task performance in both older and younger adults, providing novel evidence demonstrating that age-related cognitive control deficits can be ameliorated with sufficient incentive motivation. Additional analyses revealed clear age-related differences in motivational integration. Younger adult task performance was modulated by both monetary and liquid incentives, whereas monetary reward effects were more gradual in older adults and more strongly impacted by trial-by-trial performance feedback. A surprising discovery was that older adults shifted attention from liquid valence toward monetary reward throughout task performance, but younger adults shifted attention from monetary reward toward integrating both monetary reward and liquid valence by the end of the task, suggesting differential strategic utilization of incentives. These data suggest that older adults may have impairments in incentive integration and employ different motivational strategies to improve cognitive task performance. The findings suggest potential candidate neural mechanisms that may serve as the locus of age-related change, providing targets for future cognitive neuroscience investigations.

The perirhinal cortex supports spatial intertemporal choice stability

In order to optimize outcomes in the face of uncertainty, one must recall past experiences and extrapolate to the future by assigning values to different choice outcomes. This behavior requires an interplay between memory and reward valuation, necessitating communication across many brain regions. At the anatomical nexus of this interplay is the perirhinal cortex (PRC). The PRC is densely connected to the amygdala and orbital frontal cortex, regions that have been implicated in reward-based decision making, as well as the hippocampus. Thus, the PRC could serve as a hub for integrating memory, reward, and prediction. The PRC's role in value-based decision making, however, has not been empirically examined. Therefore, we tested the role of the PRC in a spatial delay discounting task, which allows rats to choose between a 1-s delay for a small food reward and a variable delay for a large food reward, with the delay to the large reward increasing after choice of each large reward and decreasing after each small reward. The rat can therefore adjust the delay by consecutively choosing the same reward or stabilize the delay by alternating between sides. The latter has been shown to occur once the 'temporal cost' of the large reward is established and is a decision-making process termed 'exploitation'. When the PRC was bilaterally inactivated with the GABA(A) agonist muscimol, rats spent fewer trials successfully exploiting to maintain a fixed delay compared to the vehicle control condition. Moreover, PRC inactivation resulted in an increased number of vicarious trial and error (VTE) events at the choice point, where rats had to decide between the two rewards. These behavioral patterns suggest that the PRC is critical for maintaining stability in linking a choice to a reward outcome in the face of a variable cost.

Learning from failures of protocol in cross-cultural research

The many tools that social and behavioral scientists use to gather data from their fellow humans have, in most cases, been honed on a rarefied subset of humanity: highly educated participants with unique capacities, experiences, motivations, and social expectations. Through this honing process, researchers have developed protocols that extract information from these participants with great efficiency. However, as researchers reach out to broader populations, it is unclear whether these highly refined protocols are robust to cultural differences in skills, motivations, and expected modes of social interaction. In this paper, we illustrate the kinds of mismatches that can arise when using these highly refined protocols with nontypical populations by describing our experience translating an apparently simple social discounting protocol to work in rural Bangladesh. Multiple rounds of piloting and revision revealed a number of tacit assumptions about how participants should perceive, understand, and respond to key elements of the protocol. These included facility with numbers, letters, abstract number lines, and 2D geometric shapes, and the treatment of decisions as a series of isolated events. Through on-the-ground observation and a collaborative refinement process, we developed a protocol that worked both in Bangladesh and among US college students. More systematic study of the process of adapting common protocols to new contexts will provide valuable information about the range of skills, motivations, and modes of interaction that participants bring to studies as we develop a more diverse and inclusive social and behavioral science.

Optogenetic dissection of basolateral amygdala contributions to intertemporal choice in young and aged rats

Across species, aging is associated with an increased ability to choose delayed over immediate gratification. These experiments used young and aged rats to test the role of the basolateral amygdala (BLA) in intertemporal decision making. An optogenetic approach was used to inactivate the BLA in young and aged rats at discrete time points during choices between levers that yielded a small, immediate vs. a large, delayed food reward. BLA inactivation just prior to decisions attenuated impulsive choice in both young and aged rats. In contrast, inactivation during receipt of the small, immediate reward increased impulsive choice in young rats but had no effect in aged rats. BLA inactivation during the delay or intertrial interval had no effect at either age. These data demonstrate that the BLA plays multiple, temporally distinct roles during intertemporal choice, and show that the contribution of BLA to choice behavior changes across the lifespan.

How Thinking about the Future Affects Our Decisions in the Present: Effects of Time Orientation and Episodic Future Thinking on Responses to Health Warning Messages

Past research has consistently shown that people have the tendency to discount future outcomes. However, most health messages emphasize the long-term consequences of behaviors. Building upon past research on temporal discounting, time orientation, and construal level, the current research examines how dispositional time orientation (present and future) predicts health behavior intentions and the impact of situationally-activated future orientation through episodic future thinking on the persuasiveness of long-term health warnings. An online experiment was conducted with 946 African American smokers randomly assigned to engage in either future thinking or present thinking prior to viewing a series of graphic cigarette warning labels. Results suggested that a stronger present time orientation predicts greater intentions to smoke, while a stronger future time orientation predicts greater intentions to quit smoking. Additionally, future (vs. present) thinking significantly increased intentions to quit smoking through enhanced perceived self-efficacy for quitting smoking. Theoretical and practical implications of the findings are discussed.

An investigation of the effect of trauma script exposure on risk-taking among patients with substance use disorders and posttraumatic stress disorder

Studies show that patients with substance use disorders (SUD) and posttraumatic stress disorder (PTSD) are at high risk for engaging in risky behaviors. However, these studies do not speak to the context in which these behaviors are more likely to occur. This study examined whether SUD patients with current PTSD, compared to those without a history of PTSD, are more likely to exhibit risk-taking on a laboratory-based risk-taking task, the Iowa Gambling Task (IGT), following exposure to a personalized trauma script versus a neutral script. The sample consisted of 122 trauma-exposed SUD patients with and without PTSD. Participants were administered a series of diagnostic interviews and personalized trauma scripts were created. On separate days, participants were exposed to a neutral or trauma script, followed by the IGT. Contrary to expectations, PTSD-SUD patients exhibited significantly greater risk-taking after the neutral (vs. trauma) script than those without PTSD. Moreover, whereas SUD patients without PTSD evidenced stability in IGT performance across scripts, those with PTSD exhibited significantly lower risk-taking on the IGT following the trauma (vs. neutral) script. Results provide support for the context dependent nature of risk-taking in PTSD-SUD patients and suggest they may become more risk averse in the context of trauma-related distress.

Developmental perspectives on risky and impulsive choice

Epidemiological data suggest that risk taking in the real world increases from childhood into adolescence and declines into adulthood. However, developmental patterns of behaviour in laboratory assays of risk taking and impulsive choice are inconsistent. In this article, we review a growing literature using behavioural economic approaches to understand developmental changes in risk taking and impulsivity. We present findings that have begun to elucidate both the cognitive and neural processes that contribute to risky and impulsive choice, as well as how age-related changes in these neurocognitive processes give rise to shifts in choice behaviour. We highlight how variability in task parameters can be used to identify specific aspects of decision contexts that may differentially influence risky and impulsive choice behaviour across development. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

The influence of contrived motivating operations on social discounting: Relative economic hardship affects choice

Thirty-six participants were given three social discounting surveys, and each survey was preceded by one of three contrived hypothetical scenarios. In each scenario, the participant was asked to consider situations in which either the participant (SELF), a hypothetical other (OTHER), or both the participant and the hypothetical other (BOTH) were experiencing economic hardship (i.e., needed money to avoid a negative outcome). Results replicate previous research suggesting that the probability of participants foregoing the money decreased across social distance in the BOTH and OTHER conditions; however, no discounting was observed for median responses in the SELF condition. In addition, the highest area under the curve and lowest s values were associated with the OTHER condition, and the inverse results were observed for the SELF condition. Taken together, these results suggest that relative economic hardship may act as a motivating operation affecting social discounting with the potential for further translational utility.

Can delay discounting deliver on the promise of RDoC?

The National Institute of Mental Health launched the Research Domain Criteria (RDoC) initiative to better understand dimensions of behavior and identify targets for treatment. Examining dimensions across psychiatric illnesses has proven challenging, as reliable behavioral paradigms that are known to engage specific neural circuits and translate across diagnostic populations are scarce. Delay discounting paradigms seem to be an exception: they are useful for understanding links between neural systems and behavior in healthy individuals, with potential for assessing how these mechanisms go awry in psychiatric illnesses. This article reviews relevant literature on delay discounting (or the rate at which the value of a reward decreases as the delay to receipt increases) in humans, including methods for examining it, its putative neural mechanisms, and its application in psychiatric research. There exist rigorous and reproducible paradigms to evaluate delay discounting, standard methods for calculating discount rate, and known neural systems probed by these paradigms. Abnormalities in discounting have been associated with psychopathology ranging from addiction (with steep discount rates indicating relative preference for immediate rewards) to anorexia nervosa (with shallow discount rates indicating preference for future rewards). The latest research suggests that delay discounting can be manipulated in the laboratory. Extensively studied in cognitive neuroscience, delay discounting assesses a dimension of behavior that is important for decision-making and is linked to neural substrates and to psychopathology. The question now is whether manipulating delay discounting can yield clinically significant changes in behavior that promote health. If so, then delay discounting could deliver on the RDoC promise.

Trait determinants of impulsive behavior: a comprehensive analysis of 188 rats

Impulsivity is a naturally occurring behavior that, when accentuated, can be found in a variety of neuropsychiatric disorders. The expression of trait impulsivity has been shown to change with a variety of factors, such as age and sex, but the existing literature does not reflect widespread consensus regarding the influence of modulating effects. We designed the present study to investigate, in a cohort of significant size (188 rats), the impact of four specific parameters, namely sex, age, strain and phase of estrous cycle, using the variable delay-to-signal (VDS) task. This cohort included (i) control animals from previous experiments; (ii) animals specifically raised for this study; and (iii) animals previously used for breeding purposes. Aging was associated with a general decrease in action impulsivity and an increase in delay tolerance. Females generally performed more impulsive actions than males but no differences were observed regarding delay intolerance. In terms of estrous cycle, no differences in impulsive behavior were observed and regarding strain, Wistar Han animals were, in general, more impulsive than Sprague-Dawley. In addition to further confirming, in a substantial study cohort, the decrease in impulsivity with age, we have demonstrated that both the strain and sex influences modulate different aspects of impulsive behavior manifestations.

Pattern classification differentiates decision of intertemporal choices using multi-voxel pattern analysis

In daily life, individuals frequently make trade-offs between the small-but-immediate benefits and large-but-delayed profits. This type of decision is known as intertemporal choice. Previous studies have uncovered the neurobiological mechanism of the intertemporal choice, but it still remains unclear how the patterns of brain activity predict the decisions of intertemporal choices. To fill this gap, we used functional magnetic resonance imaging (fMRI), in conjunction with the machine learning technique of multi-voxel pattern analysis (MVPA), to ascertain the predictive capability of the neuronal pattern for classifying individuals' intertemporal decisions across two independent samples. To further probe how this neuronal pattern worked in predicting individual intertemporal decision, we drew on the Power Atlas to examine the accuracies of classification within each regional mask as well. Classification findings showed that the pattern of neuronal activity over the whole-brain can correctly classify the accuracies of individual decisions up to 84.3%. Encouragingly, further analysis shows that the neuronal information encoded in three brain functional networks can predict individuals' decisions with significant discriminative power in cross-samples, namely the valuation network (e.g., striatum), the cognitive control network (e.g., dorsolateral prefrontal cortex) and the episodic prospection network (e.g., amygdala, parahippocampus gyrus, insula). Collectively, these findings advance our comprehension of the neuronal mechanism of human intertemporal decisions, and substantially reshape our understanding for this cardinal behaviour from behavioural-brain scheme to brain-behavioural configuration.

Do process simulations during episodic future thinking enhance the reduction of delay discounting for middle income participants and those living in poverty?

Two studies examined whether episodic future thinking (EFT; pre-experiencing future events) reduces discounting of future rewards (DD). No studies have investigated whether process simulations (i.e., simulating the process of executing a future event) amplify EFT's reduction of DD. Study 1 examined the effect of incorporating process simulations into EFT (N = 42, M _age = 43.27; 91% female, family income = $75,976) using a 2 × 2 factorial design with type of episodic thinking (process, nonprocess/general) and temporal perspective (EFT, episodic recent thinking) as between-subjects factors. Study 2 replicated Study 1 in a sample of adults living in poverty (N = 36; M _age = 38.44, 88% female; family income = $25,625). The results of both studies showed EFT reduced DD, but process-oriented EFT did not amplify the effect of EFT. Our findings suggest the key ingredient in EFT's effect on DD is self-projection into the future. This was also the first study to show EFT improves DD in a sample living in poverty.

Delay discounting and e-cigarette use: An investigation in current, former, and never cigarette smokers

BACKGROUND

Cigarette smokers show greater delay discounting (devaluation of delayed consequences) than non-smokers, suggesting that rapid devaluation of the future contributes to tobacco use through a mechanism in which tobacco-related health consequences are too delayed to discourage smoking. However, little work has quantified delay discounting in relation to electronic cigarette (EC) use, a tobacco product that many users believe to pose fewer negative health consequences than cigarettes.

METHODS

We assessed discounting of delayed monetary rewards in a web-based sample of 976 participants, stratified by both EC use (current and never) and cigarette use (current, former, and never).

RESULTS

Controlling for demographic variance, current EC users generally showed greater discounting than never EC users (p = .019). Current cigarette smokers also showed greater discounting than former and never smokers (p < .001). However, the between-group difference for EC use was much smaller (η_p² = .006) than for cigarette use (η_p² = .026). Moreover, differences in discounting in relation to EC use were not statistically apparent in most pairwise comparisons. Most notably, the difference between former smokers who achieved smoking cessation by transitioning to ECs (i.e., exclusive EC users) and those who have never used ECs or cigarettes was nonsignificant and small (η_p² = .010).

CONCLUSIONS

The smaller effect size for the association between delay discounting and current EC use, relative to current cigarette use, suggests that public perception of ECs as a safer alternative to cigarettes attenuates the role of delay discounting in decisions to use ECs.

Good Things for Those Who Wait: Predictive Modeling Highlights Importance of Delay Discounting for Income Attainment

Income is a primary determinant of social mobility, career progression, and personal happiness. It has been shown to vary with demographic variables like age and education, with more oblique variables such as height, and with behaviors such as delay discounting, i.e., the propensity to devalue future rewards. However, the relative contribution of each these salary-linked variables to income is not known. Further, much of past research has often been underpowered, drawn from populations of convenience, and produced findings that have not always been replicated. Here we tested a large (n = 2,564), heterogeneous sample, and employed a novel analytic approach: using three machine learning algorithms to model the relationship between income and age, gender, height, race, zip code, education, occupation, and discounting. We found that delay discounting is more predictive of income than age, ethnicity, or height. We then used a holdout data set to test the robustness of our findings. We discuss the benefits of our methodological approach, as well as possible explanations and implications for the prominent relationship between delay discounting and income.

Early life adversity and health-risk behaviors: proposed psychological and neural mechanisms

Early life adversity (ELA) is associated with poorer health in adulthood, an association explained, at least in part, by increased engagement in health-risk behaviors (HRBs). In this review, we make the case that ELA influences brain development in ways that increase the likelihood of engaging in HRBs. We argue that ELA alters neural circuitry underpinning cognitive control as well as emotional processing, including networks involved in processing threat and reward. These neural changes are associated psychologically and behaviorally with heightened emotional reactivity, blunted reward responsivity, poorer emotion regulation, and greater delay discounting. We then demonstrate that these adaptations to ELA are associated with an increased risk of smoking cigarettes, drinking alcohol, and eating high-fat, high-sugar foods. Furthermore, we explore how HRBs affect the brain in ways that reinforce addiction and further explain clustering of HRBs.

5-HT3 antagonists decrease discounting rate without affecting sensitivity to reward magnitude in the delay discounting task in mice

RATIONALE

Impulsive choice has often been evaluated in rodents according to the proportion of choices for the delayed large magnitude reinforcer (%large choice) in a delay-discounting task (DDT). However, because %large choice is influenced by both sensitivity to reinforcer magnitude and sensitivity to delayed reinforcement (i.e., discounting rate), distinctively evaluating such discounting parameters represents a critical issue demanding methods to determine each parameter in rats. The serotonin (5-HT) system is well known to be involved in impulsive choice; nevertheless, only a few studies have distinguished discounting parameters and investigated how 5-HT modulators affect discounting rate.

OBJECTIVE

Here, we performed a discounting parameter analysis in mice and examined the effects of various 5-HT modulators on discounting rate.

METHODS

We set up DDTs with different delay schedules to determine which schedule could address delay-discounting rates in mice. We examined the effect of the following drugs on impulsive choice: a 5-HT reuptake inhibitor (paroxetine), a 5-HT_1A receptor agonist (8-OH-DPAT), and two 5-HT₃ receptor antagonists (granisetron and ondansetron).

RESULTS

Mice showed typical delay discounting at the shorter delay schedules (up to 4 s delay). The %large choice under shorter, but not longer, schedules followed an exponential function and allowed us to derive discounting rates. We selected a DDT with a 4-s delay schedule for further experiments. Granisetron and ondansetron, but not paroxetine or 8-OH-DPAT, decreased discounting rates without affecting sensitivity to reinforcer magnitude.

CONCLUSION

We found that a method to calculate discounting rates in rats is also applicable to mouse models. We also provided evidence that 5-HT₃ antagonism controls impulsive choice in mice.

Using Digital Health Technologies to Understand the Association Between Movement Behaviors and Interstitial Glucose: Exploratory Analysis

BACKGROUND

Acute reductions in postprandial glucose excursions because of movement behaviors have been demonstrated in experimental studies but less so in free-living settings.

OBJECTIVE

The objective of this study was to explore the nature of the acute stimulus-response model between accelerometer-assessed physical activity, sedentary time, and glucose variability over 13 days in nondiabetic adults.

METHODS

This study measured physical activity, sedentary time, and interstitial glucose continuously over 13 days in 29 participants (mean age in years: 44.9 [SD 9.1]; female: 59%, 17/29; white: 90%, 26/29; mean body mass index: 25.3 [SD 4.1]) as part of the Sensing Interstitial Glucose to Nudge Active Lifestyles (SIGNAL) research program. Daily minutes spent sedentary, in light activity, and moderate to vigorous physical activity were associated with daily mean glucose, SD of glucose, and mean amplitude of glycemic excursions (MAGE) using generalized estimating equations.

RESULTS

After adjustment for covariates, sedentary time in minutes was positively associated with a higher daily mean glucose (mmol/L; beta=0.0007; 95% CI 0.00030-0.00103; P<.001), SD of glucose (mmol/L; beta=0.0006; 95% CI 0.00037-0.00081; P<.001), and MAGE (mmol/L; beta=0.002; 95% CI 0.00131-0.00273; P<.001) for those of a lower fitness. Additionally, light activity was inversely associated with mean glucose (mmol/L; beta=-0.0004; 95% CI -0.00078 to -0.00006; P=.02), SD of glucose (mmol/L; beta=-0.0006; 95% CI -0.00085 to -0.00039; P<.001), and MAGE (mmol/L; beta=-0.002; 95% CI -0.00285 to -0.00146; P<.001) for those of a lower fitness. Moderate to vigorous physical activity was only inversely associated with mean glucose (mmol/L; beta=-0.002; 95% CI -0.00250 to -0.00058; P=.002).

CONCLUSIONS

Evidence of an acute stimulus-response model was observed between sedentary time, physical activity, and glucose variability in low fitness individuals, with sedentary time and light activity conferring the most consistent changes in glucose variability. Further work is required to investigate the coupling of movement behaviors and glucose responses in larger samples and whether providing these rich data sources as feedback could induce lifestyle behavior change.

Are intertemporal preferences contagious? Evidence from collaborative decision making

Prior research has provided substantial insight into individuals' intertemporal preferences (i.e., preferences about delayed rewards). In the present study, we instead investigated the preferences of small groups of individuals asked to express collective intertemporal decisions. The paradigm consisted of three phases. During the precollaboration and postcollaboration phases, participants completed an intertemporal decision task individually. During the collaboration phase, participants completed a similar task in small groups, reaching mutually-agreed-upon decisions. The results suggest that group preferences were systematically related to the mean of the group members' precollaboration preferences. In addition, collaborative decision making altered the group members' intertemporal preferences. Specifically, individuals' postcollaboration preferences converged toward the preferences of their respective groups. Furthermore, we found that individuals' postcollaboration preferences were independently related to both their precollaboration preferences and the preferences of the other group members, suggesting that individuals' postcollaboration preferences represented a revision of their precollaboration preferences based on the preferences observed in other group members. In Experiment 2, we demonstrated that similar patterns of results were found whether participants were making matching judgments or binary choices.

Small Incentives Improve Weight Loss in Women From Disadvantaged Backgrounds

INTRODUCTION

Women from lower-income backgrounds have the highest rates of obesity. Thus, effective programs for this high-risk population are urgently needed. Evidence suggests that adding financial incentives to treatment helps to engage and promote health behavior change in lower-income populations; however, this has never been tested in women for obesity treatment. The purpose of this study was to examine whether adding small financial incentives to Internet weight loss treatment yields better weight loss outcomes in women from lower-income backgrounds compared with the same treatment without incentives. Weight losses in lower-versus higher-income women were also compared.

METHODS

Data were pooled from two randomized trials in which women (N=264) received either Internet behavioral weight loss treatment (IBWL) or IBWL plus incentives (IBWL+$). Weight was objectively assessed. Data were collected and analyzed from 2011 to 2017.

RESULTS

Women from lower-income backgrounds had significantly better weight loss outcomes in IBWL+$ compared with IBWL alone (6.4 [SD=4.9%] vs 2.6 [SD=4.6%], p=0.01). Moreover, a greater percentage achieved a ≥5% weight loss in IBWL+$ vs IBWL alone (52.6% vs 38.1%, p=0.01). Interestingly, the comparison between lower-income versus higher-income groups showed that, in IBWL alone, women with lower income achieved significantly poorer weight losses (3.4 [SD=4.2%] vs 4.9 [SD=4.0%], p=0.03). By contrast, in IBWL+$, weight loss outcomes did not differ by income status (5.0 [SD=5.6%] vs 5.3 [SD=3.8%], p=0.80), and a similar percentage of lower- versus higher-income women achieved a ≥5% weight loss (52.6% vs 53.8%, p=0.93).

CONCLUSIONS

An Internet behavioral weight loss program plus financial incentives may be an effective strategy to promote excellent weight losses in women with lower income, thereby enhancing equity in treatment outcomes in a vulnerable, high-risk population. These data also provide important evidence to support federally funded incentive initiatives for lower-income, underserved populations.

Evidence for Opportunity Cost Neglect in the Poor

People often neglect opportunity costs: They do not fully take into account forgone alternatives outside of a particular choice set. Several scholars have suggested that poor people should be more likely to spontaneously consider opportunity costs, because budget constraints should lead to an increased focus on trade-offs. We did not find support for this hypothesis in five high-powered experiments (total N = 2325). The experiments used different products (both material and experiential) with both high and low prices (from $8.50 to $249.99) and different methods of reminding participants of opportunity costs. High-income and low-income participants showed an equally strong decrease in willingness to buy when reminded of opportunity costs, implying that both the rich and the poor neglect opportunity costs.

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

Objectives

To examine whether delay discounting (DD) develops differently within individuals diagnosed with mild cognitive impairment (MCI) or mild Alzheimer's disease (AD).

Method

We set out to study trajectories of DD in N = 111 older adults (Mage = 75.2 years, range: 55-94, 53% female) with MCI (n = 64) or mild AD (n = 47). Data were repeatedly assessed on three measurement times over a period of 2 years.

Results

Results indicated a meaningful difference in the trajectories of DD between MCI and mild AD (t = 2.99, p = .004), with AD patients displaying higher DD rates compared with MCI. Lower intelligence (t = -2.50, p = .013) was related to higher DD. We also found reward-dependent group differences in DD (small: p = .079; medium: p = .258; large: p = .007). Age, functional ability, general cognitive ability, living situation, and marital status were not meaningfully linked to DD (all non significant). Further explorative analyses revealed an increase in DD in patients whose cognitive symptoms had progressed at time 2, compared with more stable courses of mild AD or MCI (diagnosed at time 2).

Discussion

Our results point toward an increase in DD as a function of advanced cognitive decline.

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

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

The effects of normal aging on multiple aspects of financial decision-making

OBJECTIVES

Financial decision-making (FDM) is crucial for independent living. Due to cognitive decline that accompanies normal aging, older adults might have difficulties in some aspects of FDM. However, an improved knowledge, personal experience and affective decision-making, which are also related to normal aging, may lead to a stable or even improved age-related performance in some other aspects of FDM. Therefore, the present explorative study examines the effects of normal aging on multiple aspects of FDM.

METHODS

One-hundred and eighty participants (range 18-87 years) were assessed with eight FDM tests and several standard neuropsychological tests. Age effects were evaluated using hierarchical multiple regression analyses. The validity of the prediction models was examined by internal validation (i.e. bootstrap resampling procedure) as well as external validation on another, independent, sample of participants (n = 124). Multiple regression and correlation analyses were applied to investigate the mediation effect of standard measures of cognition on the observed effects of age on FDM.

RESULTS

On a relatively basic level of FDM (e.g., paying bills or using FDM styles) no significant effects of aging were found. However more complex FDM, such as making decisions in accordance with specific rules, becomes more difficult with advancing age. Furthermore, an older age was found to be related to a decreased sensitivity for impulsive buying. These results were confirmed by the internal and external validation analyses. Mediation effects of numeracy and planning were found to explain parts of the association between one aspect of FDM (i.e. Competence in decision rules) and age; however, these cognitive domains were not able to completely explain the relation between age and FDM.

CONCLUSION

Normal aging has a negative influence on a complex aspect of FDM, however, other aspects appear to be unaffected by normal aging or improve.

Age and impulsive behavior in drug addiction: A review of past research and future directions

Impulsive behavior is implicated in the initiation, maintenance, and relapse of drug-seeking behaviors involved in drug addiction. Research shows that changes in impulsive behavior across the lifespan contribute to drug use and addiction. The goal of this review is to examine existing research on the relationship between impulsive behavior and drug use across the lifespan and to recommend directions for future research. Three domains of impulsive behavior are explored in this review: impulsive behavior-related personality traits, delay discounting, and prepotent response inhibition. First, we present previous research on these three domains of impulsive behavior and drug use across developmental stages. Then, we discuss how changes in impulsive behavior across the lifespan are implicated in the progression of drug use and addiction. Finally, we discuss the relatively limited attention given to middle-to-older adults in the current literature, consider the validity of the measures used to assess impulsive behavior in middle-to-older adulthood, and suggest recommendations for future research.

Strong seduction: impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence

Alcohol-related cues acquire incentive salience through Pavlovian conditioning and then can markedly affect instrumental behavior of alcohol-dependent patients to promote relapse. However, it is unclear whether similar effects occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-dependent patients and 91 healthy controls who completed a delay discounting task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer (PIT) paradigm employing both alcohol-unrelated and alcohol-related stimuli. To modify instrumental choice behavior, we tiled the background of the computer screen either with conditioned stimuli (CS) previously generated by pairing abstract pictures with pictures indicating monetary gains or losses, or with pictures displaying alcohol or water beverages. CS paired to money gains and losses affected instrumental choices differently. This PIT effect was significantly more pronounced in patients compared to controls, and the group difference was mainly driven by highly impulsive patients. The PIT effect was particularly strong in trials in which the instrumental stimulus required inhibition of instrumental response behavior and the background CS was associated to monetary gains. Under that condition, patients performed inappropriate approach behavior, contrary to their previously formed behavioral intention. Surprisingly, the effect of alcohol and water pictures as background stimuli resembled that of aversive and appetitive CS, respectively. These findings suggest that positively valenced background CS can provoke dysfunctional instrumental approach behavior in impulsive alcohol-dependent patients. Consequently, in real life they might be easily seduced by environmental cues to engage in actions thwarting their long-term goals. Such behaviors may include, but are not limited to, approaching alcohol.

Let's decide together: Differences between individual and joint delay discounting

This study addressed the question whether or not social collaboration has an effect on delay discounting, the tendency to prefer sooner but smaller over later but larger delivered rewards. We applied a novel paradigm in which participants executed choices between two gains in an individual and in a dyadic decision-making condition. We observed how participants reached mutual consent via joystick movement coordination and found lower discounting and a higher decisions' efficiency. In order to establish the underlying mechanism for dyadic variation, we further tested whether these differences emerge from social facilitation or inner group interchange.

Cognitive Control Modulates Effects of Episodic Simulation on Delay Discounting in Aging

Enhancing prospective thinking by tagging the future with specific episodic events has been shown to reduce delay discounting in young age (“tag-effect”). So far, it is unclear whether such beneficial effect extends to old adulthood. Since the general ability of future thinking and cognitive control are crucial modulators of temporal discounting in young age, potential age-related decline in these functions might impact on the effect. We focused on this issue by combining functional magnetic resonance imaging (fMRI) with an established intertemporal choice task including episodic “tags” in healthy older participants. Future thinking ability was assessed using autobiographical interviews for future event simulations and a visual search task was applied to assess participants’ cognitive control ability. In contrast to previous data in young adults, the group of older participants did not benefit from tagging the future with episodic events. Older participants’ cognitive control function was directly associated with discounting rates in the episodic conditions: the less the older adults were able to focus their attention the less they benefited from the inclusion of episodic events. Consistent with this, imaging results revealed that: (a) subjective value (SV) signals in the hippocampus and the anterior cingulate cortex (ACC) as well as; (b) hippocampal-striatal coupling during the episodic condition were positively related to participants’ control capacity. Our findings highlight the critical role of executive functioning for the simultaneous integration of episodic information with future value computation in aging. Boosting delay gratification by including episodic tags might hence be limited in older individuals with pronounced decline in distraction control.

Temporal preference in individuals reporting chronic pain: discounting of delayed pain-related and monetary outcomes

Opioid therapy for pain is associated with an increased risk for substance use disorders. This study's purpose was to determine the association between opioid misuse propensity (Screener and Opioid Assessment for Patients in Pain-Revised) and delay discounting (DD), a behavioral process linked to substance use disorders, which quantifies the extent to which outcomes are devalued because of their delay. Participants reporting chronic pain (N = 249) answered pain and opioid use questions and then completed 4 DD tasks. Each of these tasks assessed either money or pain consequences, framed as either rewards or punishments. Each task involved hypothetical choices between immediate smaller vs delayed larger consequences. The extant Monetary Choice Questionnaire assessed DD of money rewards, and a modified version assessed discounting of money losses (immediate smaller loss vs larger delayed loss). Based on the Monetary Choice Questionnaire, the novel Pain Relief Choice Questionnaire assessed choices between an immediate short duration of pain relief vs a longer duration of pain relief. Similarly, the novel Additional Pain Choice Questionnaire assessed choices between an immediate short duration of additional pain vs a longer duration of additional pain. Discounting of both additional pain and money losses were significantly associated with high Screener and Opioid Assessment for Patients in Pain-Revised scores-indicating participants at greatest risk for opioid misuse discount future punishments rather than future rewards compared with those at low risk. Measures of DD may have promise in more accurately identifying individuals at highest risk for opioid misuse during chronic opioid therapy.

Does Hunger Contribute to Socioeconomic Gradients in Behavior?

Recent research has uncovered many examples of socioeconomic gradients in behavior and psychological states. As yet there is no theoretical consensus on the nature of the causal processes that produce these gradients. Here, I present the hunger hypothesis, namely the claim that part of the reason that people of lower socioeconomic position behave and feel as they do is that they are relatively often hungry. The hunger hypothesis applies in particular to impulsivity-hyperactivity, irritability-aggression, anxiety, and persistent narcotic use, all of which have been found to show socioeconomic gradients. I review multiple lines of evidence showing that hunger produces strong increases in these outcomes. I also review the literatures on food insufficiency and food insecurity to show that, within affluent societies, the poor experience a substantial burden of hunger, despite obtaining sufficient or excess calories on average. This leads to the distinctive prediction that hunger is an important mediator of the relationships between socioeconomic variables and the behavioral/psychological outcomes. This approach has a number of far-reaching implications, not least that some behavioral and psychological differences between social groups, though persistent under current economic arrangements, are potentially highly reversible with changes to the distribution of financial resources and food.

Increased temporal discounting in bulimia nervosa

OBJECTIVE

There is evidence that people with eating disorders display altered intertemporal choice behavior (the degree of preference for immediate rewards over delayed rewards). Compared to healthy controls (HC), individuals with anorexia nervosa and binge-eating disorder show decreased and increased rates of temporal discounting (TD; the devaluation of delayed rewards), respectively. This is the first study to investigate TD in people with bulimia nervosa (BN).

METHOD

Thirty-nine individuals with BN (2 men) and 53 HC (9 men) completed a hypothetical monetary TD task. Over 80 binary choices, participants chose whether they would prefer to receive a smaller amount of money available immediately or a larger amount available in 3 months. Self-reported ability to delay gratification (the behavioral opposite of TD) was also measured.

RESULTS

Individuals with BN showed greater TD (i.e., a preference for smaller-sooner rewards) and a decreased self-reported capacity to delay gratification relative to HC. Experimental groups did not differ in age, gender ratio, or BMI.

DISCUSSION

Increased rates of TD may contribute to some of the core symptoms of BN that appear to involve making choices between immediate and delayed rewards (i.e., binge-eating and compensatory behaviors). Altered intertemporal choice behavior could therefore be a relevant target for intervention in this patient group. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1077-1081).

Adult age differences in decision making across domains: Increased discounting of social and health-related rewards

Although research on aging and decision making continues to grow, the majority of studies examine decisions made to maximize monetary earnings or points. It is not clear whether these results generalize to other types of rewards. To investigate this, we examined adult age differences in 92 healthy participants aged 22 to 83. Participants completed 9 hypothetical discounting tasks, which included 3 types of discounting factors (time, probability, effort) across 3 reward domains (monetary, social, health). Participants made choices between a smaller magnitude reward with a shorter time delay/higher probability/lower level of physical effort required and a larger magnitude reward with a longer time delay/lower probability/higher level of physical effort required. Older compared with younger individuals were more likely to choose options that involved shorter time delays or higher probabilities of experiencing an interaction with a close social partner or receiving health benefits from a hypothetical drug. These findings suggest that older adults may be more motivated than young adults to obtain social and health rewards immediately and with certainty. (PsycINFO Database Record

When good news leads to bad choices

Pigeons and other animals sometimes deviate from optimal choice behavior when given informative signals for delayed outcomes. For example, when pigeons are given a choice between an alternative that always leads to food after a delay and an alternative that leads to food only half of the time after a delay, preference changes dramatically depending on whether the stimuli during the delays are correlated with (signal) the outcomes or not. With signaled outcomes, pigeons show a much greater preference for the suboptimal alternative than with unsignaled outcomes. Key variables and research findings related to this phenomenon are reviewed, including the effects of durations of the choice and delay periods, probability of reinforcement, and gaps in the signal. We interpret the available evidence as reflecting a preference induced by signals for good news in a context of uncertainty. Other explanations are briefly summarized and compared.

Delay discounting of gains and losses, glycemic control and therapeutic adherence in type 2 diabetes

OBJECTIVE

Delay discounting is the tendency to prefer smaller, sooner rewards to larger, later ones. Poor adherence in type 2 diabetes could be partially explained by a discounted value of health, as a function of delay. Delay discounting can be described with a hyperbolic model characterized by a coefficient, k. The higher k, the less future consequences are taken into account when making decisions. This study aimed to determine whether k would be correlated with glycated hemoglobin and adherence in type 2 diabetes.

METHODS

Ninety-three patients were recruited in two diabetology departments. Delay discounting coefficients were measured with a computerized task. HbA1c was recorded and adherence was assessed by questionnaires. Potential socio-demographic and clinical confounding factors were collected.

RESULTS

There was a positive correlation between delay discounting of gains and HbA1c (r=0.242, P=0.023). This association remained significant after adjusting for potential confounding factors (F=4.807, P=0.031, η²=0.058). This association was partially mediated by adherence to medication (β=0.048, 95% CI [0.004-0.131]).

CONCLUSIONS

Glycemic control is associated with delay discounting in patients suffering from type 2 diabetes. Should these findings be replicated with a prospective design, they could lead to new strategies to improve glycemic control among these patients.