Physical and cognitive effort discounting of hypothetical monetary rewards

What's in a Message? Effects of Mental Fatigue and Message Framing on Motivation for Physical Activity

Many adults worldwide do not meet current physical activity (PA) guidelines. Mental fatigue decreases the likelihood of choosing to engage in PA. Message framing may enhance PA motivation when fatigued. We examined the effects of mental fatigue and message framing on PA motivation with additional focus on the messaging "congruency effect." Three hundred and twenty undergraduates completed measures of dispositional motivational orientation and were exposed to either gain-framed or loss-framed messages before completing an effort discounting questionnaire. Results showed lower motivation to engage in PA of higher intensities and longer durations. Direct effects of message framing on PA motivation were not significant. Interaction effects revealed that participants receiving messages congruent with their dominant motivational orientation showed increased motivation for light-intensity PA and decreased motivation for vigorous-intensity PA as mental fatigue increased. Findings suggest that providing messages congruent with one's dominant motivational orientation may increase motivation for engaging in light-intensity PA when fatigued.

Validation of a novel effort-discounting assessment and evaluation of the effort-delay confound on effort discounting

A vast literature highlights the prevalence of impulsive decision making in maladaptive outcomes. Most research has focused on one form-delay discounting. Less research has focused on effort discounting, possibly because of a lack of a standardized task for assessment. In published effort-discounting tasks, effort is conceptualized in many ways, making it difficult to compare findings across studies. Additionally, most effort-discounting tasks do not control for the time inherent in completing the effortful task, which makes it difficult to disentangle effort discounting from delay discounting. The current study evaluated the validity of a novel hypothetical effort-discounting task. The novel task was used to evaluate the influence of the effort-delay confound on rates of effort discounting in humans. Participants were randomly assigned to complete a confounded or a controlled version of the novel effort-discounting task. The effort-discounting data were well described by hyperbolic and exponential functions. When effort and delay were confounded, effort-discounting rates were significantly higher than when effort alone influenced discounting. The results suggest that data that are produced by effort-discounting tasks that do not control the effort-delay confound should be interpreted cautiously because they are also influenced by delay discounting. Task limitations and future directions are discussed.

Greater Risk Taking in Cosmetic Surgery Acceptance and History: An Experimental and Computational Study

Cosmetic surgery is ever more affordable and accessible, but carries physical and psychological risks. Yet, no study to date has directly examined risk-taking behaviour under controlled conditions, beyond self-report and in relation to cosmetic surgery attitudes. We used the Balloon Analogue Risk Task and advanced computational modelling to measure decision-making behaviour and identify the latent parameters driving behaviour associated with cosmetic surgery attitudes in women with no cosmetic surgery history (N = 265) and a subsample of women with a cosmetic surgery history (N = 24). Risk taking was higher in women with greater acceptance and history of cosmetic surgery. Computational modelling revealed increased risk taking in women with greater acceptance of cosmetic surgery when decisions were made with greater knowledge of loss (risk) and not when the likelihood of loss was unknown (uncertainty). When women with greater acceptance of cosmetic surgery made decisions, they also placed less emphasis on possible losses (reduced loss aversion). Our findings suggest that women seeking cosmetic procedures may be less sensitive to losses and thus make more risky decisions. Greater emphasis should be placed on communicating potential losses rather than just the associated risks to women considering cosmetic procedures.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Is It Really Worth the Effort? Examining the Effects of Mental Fatigue on Physical Activity Effort Discounting

Physical activity (PA) guidelines are informed by epidemiological evidence but do not account for people's motivation for exerting physical effort. Previous research has shown that people are less motivated to engage in moderate- to vigorous-intensity PA when fatigued. In a two-study series, we investigated how intensity and duration affected people's willingness to engage in PA using an effort-discounting paradigm. A secondary purpose was to examine whether effort discounting was affected by mental fatigue. Both studies revealed a significant Intensity × Duration interaction demonstrating a reduced willingness to engage in PA of higher intensities across increasing duration levels. Study 1 demonstrated greater effort discounting for vigorous-intensity PA with increasing mental fatigue; however, this effect was not observed in Study 2. Findings provide novel insight toward people's motivation for engaging in PA based on the properties of the task, and some evidence suggesting feelings of fatigue may also influence motivation to exert physical effort.

Everything Comes at a Price: Considerations in Modeling Effort-Based Choice

When observing human behavior, one of the key factors determining choice is effort. It is often assumed that people prefer an easier course of action when the alternative yields the same benefits. However, recent research demonstrates that this is not always the case: effort is not always costly and can also add value. A promising avenue to study effort-based choice is to utilize formal decision models that enable quantitative modeling. In this paper, we aim to present an overview of the current approaches to modeling effort-based choice and discuss some considerations that stem from theoretical and practical issues (present and previous) in studies on the role of effort, focusing on the connections and discrepancies between formal models and the findings from the body of empirical research. Considering that effort can, in some circumstances, act as a cost and as a benefit, reconciling these discrepancies is a practical and theoretical challenge that can ultimately lead to better predictions and increased model validity. Our review identifies and discusses these discrepancies providing direction for future empirical research.

Delay and Effort-Based Discounting, and the Role of Bodily Awareness, In People Experiencing Long-Term Pain: A Cross-Sectional Study

Pain interventions typically include effortful exercise and long-term treatment - ie, short-term costs (effort) with delayed benefit (improved pain and/or function). Thus, understanding if long-term pain influences decision-making in context of delays and effort is essential given clear relevance to treatment uptake and/or adherence. We evaluated delay and effort attitudes in those experiencing chronic pain (n = 391) and in pain-free controls (n = 263). Additionally, we investigated the role of bodily sensation awareness and/or interpretation as potential contributing factors to altered decision-making. Volunteers completed three discounting questionnaires, assessing the influence of temporal delays (gains, losses) and effort on devaluation of monetary outcomes. Individuals with chronic pain had more short-sighted decisions for monetary gains, but not losses, and decreased willingness to undertake effort for monetary gains than the No Pain group. The Pain group had higher bodily sensation awareness and while this related to higher impulsivity, delay and effort discounting, neither awareness nor interpretation of bodily sensations interacted with pain levels or explained group differences in discounting behavior. These findings suggest that impaired delay and effort-based discounting is present in people with chronic pain, and that this may be driven by pain-induced changes, but not pain-induced enhancements in bodily sensation awareness and/or interpretation. Exploring the utility of interventions targeting discounting behavior is warranted. Data availability: Study materials are available here: https://osf.io/zexm7/?view_only=c9848597361c41808c612874da6f33b7. PERSPECTIVE: People with chronic pain make more short-sighted decisions (prefer less reward sooner) and decreased willingness to undertake effort (prefer less reward with little effort) for monetary gains than people without pain. Interventions targeting discounting behavior may help improve both uptake and adherence for evidence-based, effortful treatments, such as exercise.

Gain-loss asymmetry in delay and effort discounting of different amounts

Loss aversion entails that people attribute greater weight to losses than to equivalent gains. In terms of discounting, it is reflected in a higher discounting rate for gains than for losses. Research on delay discounting indicates that such gain-loss asymmetry may depend on the amount of the outcome being considered. Consequently, here we address the question of how gains and losses are discounted in delay or effort conditions (physical or cognitive) across four outcome amounts. Our results replicate previous findings for intertemporal choices by showing that losses are discounted more slowly than gains, but only for smaller amounts-with no evidence of an asymmetrical evaluation for larger amounts. In physical effort discounting, we found an inverse asymmetry for the smallest amount tested (gains are discounted less steeply than losses). However, this effect was absent for larger amounts. We found no evidence to support a gain-loss asymmetry in the evaluation of gains or losses in cognitive effort. Overall, our findings indicate that loss aversion may not be as pervasive as previously expected, at least when decisions are effort-based.

Dispositional individual differences in cognitive effort investment: establishing the core construct

BACKGROUND

Individuals tend to avoid effortful tasks, regardless of whether they are physical or mental in nature. Recent experimental evidence is suggestive of individual differences in the dispositional willingness to invest cognitive effort in goal-directed behavior. The traits need for cognition (NFC) and self-control are related to behavioral measures of cognitive effort discounting and demand avoidance, respectively. Given that these traits are only moderately related, the question arises whether they reflect a common core factor underlying cognitive effort investment. If so, the common core of both traits might be related to behavioral measures of effort discounting in a more systematic fashion. To address this question, we aimed at specifying a core construct of cognitive effort investment that reflects dispositional differences in the willingness and tendency to exert effortful control.

METHODS

We conducted two studies (N = 613 and N = 244) with questionnaires related to cognitive motivation and effort investment including assessment of NFC, intellect, self-control and effortful control. We first calculated Pearson correlations followed by two mediation models regarding intellect and its separate aspects, seek and conquer, as mediators. Next, we performed a confirmatory factor analysis of a hierarchical model of cognitive effort investment as second-order latent variable. First-order latent variables were cognitive motivation reflecting NFC and intellect, and effortful self-control reflecting self-control and effortful control. Finally, we calculated Pearson correlations between factor scores of the latent variables and general self-efficacy as well as traits of the Five Factor Model of Personality for validation purposes.

RESULTS

Our findings support the hypothesized correlations between the assessed traits, where the relationship of NFC and self-control is specifically mediated via goal-directedness. We established and replicated a hierarchical factor model of cognitive motivation and effortful self-control that explains the shared variance of the first-order factors by a second-order factor of cognitive effort investment.

CONCLUSIONS

Taken together, our results integrate disparate literatures on cognitive motivation and self-control and provide a basis for further experimental research on the role of dispositional individual differences in goal-directed behavior and cost-benefit-models.

Effort-Related Decision-Making in ADHD

ADHD is defined by behavioral symptoms that are not well characterized in relation to ADHD’s neurobiological mechanisms. This approach has limited our ability to define ADHD nosology and predict outcomes because it does not systematically examine facets of the disorder such as the inability to maintain cognitively effortful activities, as promoted in the NIMH RDoC approach. Existing data indicate ADHD is associated with differences in reward valuation and processing, but we do not know whether ADHD is also associated with higher levels of aversion to exerting cognitive effort and/or altered reward x effort interactions. Our ongoing study addresses this knowledge gap by examining individuals’ preferences between rewards associated with minimal effort and reward alternatives with a higher payoff but higher effort costs (“effort discounting”); thereby permitting us to characterize differences in biases and tradeoffs during effort-related decision-making in ADHD. The study takes advantage of a well-defined sample of ADHD-diagnosed and healthy control individuals to address three aims. First, we determine whether ADHD is associated with steeper discounting of larger, more effortful rewards. Second, we examine the subjective perception of effort in youth diagnosed with ADHD and healthy controls using tasks requiring varying levels of cognitive effort. Third, we explore relationships amongst indices of effort discounting, theoretically-related traits (e.g., grit, distress tolerance), biomarkers of effort-related decision-making (eye movements and pupil size), and various cognitive measures. Successful completion of the aims will permit us to better characterize ADHD-healthy control differences and lay a foundation for more computational approaches to ADHD diagnostic criteria.

On Four Types of Devaluation of Outcomes Due to Their Costs: Delay, Probability, Effort, and Social Discounting

Discounting refers to decreases in the subjective value of an outcome with increases in some attribute of that outcome. The attributes most commonly studied are delay and probability, with far less research on effort and social discounting. Although these attributes all represent costs that reduce subjective value, it is as yet unclear how the extent to which they do so is related at the individual level. Accordingly, the present study examined the degree to which individual participants discounted hypothetical monetary rewards on each of four discounting tasks in which the delay, probability, effort, and number of people with whom the money was to be shared were manipulated. At the group level, larger amounts were discounted less steeply than smaller amounts when delay and effort were varied, whereas larger amounts were discounted more steeply when probability and number of people were varied. At the individual level, the correlational pattern was examined using exploratory factor analysis. A six-factor structure (with separate factors for delay and effort, and two factors each for social and probability discounting) described the relations among indifference points. At a more molar level, a two-factor structure, which corresponded to the direction of the observed magnitude effects, described the relations among area-under-the-curve measures of discounting in the eight conditions resulting from crossing two monetary amounts with the four cost factors. We conclude that despite sharing some similarities, individual and group differences in discounting involving the different types of costs reflect mostly separate processes and traits.

Willing to Work But Not to Wait: Individuals with Greater Alcohol Use Disorder Show Increased Delay Discounting Across Commodities and Less Effort Discounting for Alcohol

BACKGROUND

Delay discounting refers to the devaluation of a reward given increasing delays to delivery. Similarly, effort discounting refers to the devaluation of a reward given increasing effort required to obtain it. Individuals with substance use disorder show higher rates of delay discounting, exacerbating short-term positive reinforcement at the expense of long-term consequences. This study explores how effort discounting compares to delay discounting behavior among alcohol users as well as how these preferences change between monetary and alcohol rewards.

METHODS

A total of 100 participants completed an online survey through Amazon Mechanical Turk. Participant alcohol use was evaluated using DSM-5 and the Alcohol Use Disorders Identification Test criteria. All participants completed 4 randomized discounting tasks involving delay or effort discounting, in which the reward was money or alcohol. A follow-up experiment (n = 423) added the alcohol purchase task to assess alcohol valuation.

RESULTS

Individuals with greater alcohol use disorder (AUD) severity discounted future money and alcohol significantly more than those with less AUD. However, individuals meeting more DSM-5 criteria were only willing to perform more effort for alcohol. The follow-up experiment replicated these findings and demonstrated that individuals with greater AUD also showed an increased valuation of alcohol and alcohol value-mediated effort discounting.

CONCLUSIONS

These results suggest that individuals with greater AUD were less willing to wait for money or alcohol. While all participants were willing to work for money regardless of AUD severity, individuals with greater AUD showed increased valuation of alcohol drinks and were willing to exert more effort to obtain alcohol. Together, these results paint a picture of individuals with increased AUD as both more impulsive and willing to work to obtain alcohol, contributing to our understanding of decision making among individuals who abuse substances.

Physical and cognitive effort discounting across different reward magnitudes: Tests of discounting models

The effort required to obtain a rewarding outcome is an important factor in decision-making. Describing the reward devaluation by increasing effort intensity is substantial to understanding human preferences, because every action and choice that we make is in itself effortful. To investigate how reward valuation is affected by physical and cognitive effort, we compared mathematical discounting functions derived from research on discounting. Seven discounting models were tested across three different reward magnitudes. To test the models, data were collected from a total of 114 participants recruited from the general population. For one-parameter models (hyperbolic, exponential, and parabolic), the data were explained best by the exponential model as given by a percentage of explained variance. However, after introducing an additional parameter, data obtained in the cognitive and physical effort conditions were best described by the power function model. Further analysis, using the second order Akaike and Bayesian Information Criteria, which account for model complexity, allowed us to identify the best model among all tested. We found that the power function best described the data, which corresponds to conventional analyses based on the R2 measure. This supports the conclusion that the function best describing reward devaluation by physical and cognitive effort is a concave one and is different from those that describe delay or probability discounting. In addition, consistent magnitude effects were observed that correspond to those in delay discounting research.