Binary components of food reinforcement: Amplitude and persistence

The subjective value of social context in people who use cannabis

Disordered cannabis use is linked to social problems, which could be explained by a subjective devaluation of nondrug social contexts and/or an overvaluation of cannabis-paired options relative to nondrug alternatives. To examine these hypotheses, measures to assess the subjective value of social- and/or cannabis-paired contexts were collected in people who use cannabis (n = 85) and controls (n = 98) using crowdsourcing methods. Measures included a cued concurrent choice task that presented two images (cannabis, social, social cannabis, and neutral images) paired with monetary options, hypothetical purchase tasks that included access to social parties with and without a cannabis "open bar," and the Social Anhedonia Scale (SAS). Little evidence was found to suggest that the cannabis group undervalued social contexts. People who used cannabis demonstrated a preference for social- versus neutral-cued options, and no preference for cannabis- versus social cannabis-cued options on the choice task. In addition, social party demand and SAS scores did not differ between groups. In contrast, we observed evidence for an overvaluation of cannabis context in people who use cannabis, including preference for social cannabis- versus social-cued options, and more disadvantageous choices for cannabis-cued options on the choice task, as well as more intense and inelastic demand for the social cannabis party compared to the social party. These results suggest that social problems associated with cannabis use could be at least partially explained by an overvaluation of cannabis-paired options, rather than devaluation of nondrug social-paired options, in the value calculations underlying drug use decisions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Episodic future thinking improves intertemporal choice and food choice in individuals with higher weight: A systematic review and meta-analysis

Episodic future thinking (EFT) strengthens self-regulation abilities by increasing the perceived value of long-term reinforcements and reducing impulsive choice in delay discounting tasks. As such, EFT interventions have the potential to improve dietary and eating-related decision-making in individuals with obesity or binge eating symptoms, conditions associated with elevated delay discounting. Here, we meta-analyzed evidence from 12 studies that assessed whether EFT interventions improve delay discounting and real-world food choice compared to control interventions. Included studies involved 951 adults with overweight or obesity (body mass index [BMI] ≥25). There were no studies involving participants with binge eating disorder. EFT intervention pooled effects were significant, improving delay discounting with a medium effect, g = 0.55, p < 0.0001, and subsequent food choice outcomes with a small effect, g = 0.31, p < 0.01. Notably, our review is the first to analyze mechanisms of effect in this population, demonstrating that improvements were greater when temporal horizons of EFT episodes were aligned with delay discounting tasks and more distant horizons predicted far-transfer to subsequent dietary and eating-related choices. Our findings thus show that EFT is an effective intervention for individuals with higher weight at risk of adverse health consequences.

Applying behavioral economics-based approaches to examine the effects of liquid sucrose consumption on motivation

Overconsumption of sugar contributes to obesity in part by changing the activity of brain areas that drive the motivation to seek out and consume food. Sugar-sweetened beverages are the most common source of excess dietary sugar and contribute to weight gain. However, very few studies have assessed the effects of liquid sucrose consumption on motivation. This is due in part to the need for novel approaches to assess motivation in pre-clinical models. To address this, we developed a within-session behavioral economics procedure to assess motivation for liquid sucrose. We first established and validated the procedure: we tested several sucrose concentrations, evaluated sensitivity of the procedure to satiety, and optimized several testing parameters. We then applied this new procedure to determine how intermittent vs. continuous access to liquid sucrose (1 M) in the home cage affects sucrose motivation. We found that intermittent liquid sucrose access results in an escalation of sucrose intake in the home cage, without altering motivation for liquid sucrose during demand testing (1 M or 0.25 M) compared to water-maintained controls. In contrast, continuous home cage access selectively blunted motivation for 1 M sucrose, while motivation for 0.25 M sucrose was similar to intermittent sucrose and control groups. Thus, effects of continuous home cage liquid sucrose access were selective to the familiar sucrose concentration. Finally, effects of sucrose on motivation recovered after removal of liquid sucrose from the diet. These data provide a new approach to examine motivation for liquid sucrose and show that escalation of intake and motivation for sucrose are dissociable processes.

Binge eating, overeating and food addiction: Approaches for examining food overconsumption in laboratory rodents

Overeating ranges in severity from casual overindulgence to an overwhelming drive to consume certain foods. At its most extreme, overeating can manifest as clinical diagnoses such as binge eating disorder or bulimia nervosa, yet subclinical forms of overeating such as emotional eating or uncontrolled eating can still have a profoundly negative impact on health and wellbeing. Although rodent models cannot possibly capture the full spectrum of disordered overeating, studies in laboratory rodents have substantially progressed our understanding of the neurobiology of overconsumption. These experimental approaches range from simple food-exposure protocols that promote binge-like eating and the development of obesity, to more complex operant procedures designed to examine distinct 'addiction-like' endophenotypes for food. This review provides an overview of these experimental approaches, with the view to providing a comprehensive resource for preclinical investigators seeking to utilize behavioural models for studying the neural systems involved in food overconsumption.

Validation of the Food Purchase Task (FPT) in a clinical sample of smokers with overweight and obesity

Obesity is a major health problem associated with disease burden and mortality. In this context, analyzing food as a powerful reinforcer from a behavioral economics framework could be relevant for the treatment and prevention of obesity. The purposes of this study were to validate a food purchase task (FPT) in a clinical sample of Spanish smokers with overweight and obesity and to assess the internal structure of the FPT. We also analyzed the clinical utility of single-item breakpoint (i.e., commodity price that suppresses demand). A total of 120 smokers [% females: 54.2; M_age = 52.54; SD = 10.34] with overweight and obesity completed the FPT and weight/eating-related variables. Principal component analysis was used to examine the FPT structure, and a set of correlations were used to examine the relationship between the FPT, eating and weight-related variables. The FPT demonstrated robust convergent validity with other measures of eating. Higher food demand was related to higher food craving (r = .33), more binge eating problems (r = 0.39), more weight gain concerns (r = 0.35), higher frequency of both controlled (r = 0.37) and uncontrolled (r = 0.30) grazing, as well as to an eating style in response to emotions (r = 0.34) and external eating (r = 0.34). Of the demand indices, Intensity and O_max showed the highest magnitudes of effects. The FPT factors, persistence and amplitude, do not improve individual FPT indices; and the single-item breakpoint was not related to any eating or weight variable. The FPT is a valid measure of food reinforcement with potential clinical utility in smokers with obesity/overweight.

At-Risk Drinking, Operant Demand, and Cross-Commodity Discounting as Predictors of Drunk Driving in Underage College Women

Behavioral economics offers unique tools for assessing value and motivation associated with college drinking. Tasks that model changes in consumption as a function of price (operant demand) or the decline in an outcome's subjective value as a function of time-to-occurrence (delay discounting) provide valuable information that may efficiently supplement clinical screening instruments when characterizing alcohol use severity. The first aim of this investigation was to examine the extent to which at-risk drinking, operant demand for alcohol, and single- and cross-commodity discounting of money and alcohol predict adverse consequences of past-month drinking in underage college women (N = 72). The second aim was to determine whether these clinical and behavioral economic measures could significantly predict the odds of past-month drunk driving, a serious public health concern due to the increasing prevalence of heavy episodic drinking among women in their first 1 - 2 years of college. Results showed that higher scores on the consumption factor of the Alcohol Use Disorder Identification Test (AUDIT-C), greater Persistence (consumption amidst constraint) and Amplitude (maximum consumption) of demand, as well as lower rates of discounting for choices between receiving alcohol now or double the amount after a delay (choosing the larger amount of alcohol even when it is delayed) significantly predicted adverse consequences of past-month drinking. Moreover, scores on the AUDIT-C, Amplitude of demand, and higher rates of discounting for choices between receiving alcohol now and money later (choosing immediately available alcohol at the expense of double the equivalent in delayed money) significantly predicted past-month drunk driving. We contend that operant demand along with single- and cross-commodity discounting can be viewed as intersecting measures of reinforcer value with clinical relevance to college women.

A pilot study of a school lunchroom intervention in a predominately Latinx sample

OBJECTIVE

The purpose of the study was to assess the feasibility of an environmental school lunchroom intervention ('Smarter Lunchrooms') and test initial efficacy within a predominately Latinx population.

DESIGN

We collected baseline and intervention lunchroom food consumption and waste data in a pre-post, single group design. Meal consumption data was analyzed using Nutrition Data System for Research software to obtain estimates of nutritional content.

MAIN OUTCOME MEASURES

Feasibility.

SECONDARY MEASURES

Plate Waste, Nutrient Intake.

RESULTS

Participants were 88 1st-4th graders (51% female; 77% Latinx). Our recruitment rate was 45%, we were able to implement 8 Smarter Lunchroom strategies, and we were able to collect 82 baseline plate photos (93%) and 80 intervention photos (90%) of school lunches. On average, students threw away more than half of their meals on both days. Fruit consumption and fiber per 1000 kcal were significantly poorer at intervention compared to baseline.

CONCLUSIONS

Our findings highlight challenges in collecting consumption data in a real-world setting. We describe directions for future research taking into consideration our "lessons learned" from this formative work.

Behavioral Economic Approaches to Childhood Obesity Prevention Nutrition Policies: A Social Ecological Perspective

Childhood obesity is a significant public health concern associated with the development of the leading causes of death. Dietary factors largely contribute to childhood obesity, but prevention interventions targeting these factors have reported relatively small effect sizes. One potential explanation for the ineffectiveness of prevention efforts is lack of theoretical grounding. Behavioral economic (BE) theory describes how people choose to allocate their resources and posits that some children place higher value on palatable foods (relative reinforcing value of food) and have difficulty delaying food rewards (delay discounting). These seemingly individual-level decision making processes are influenced by higher-level variables (e.g., environment/policy) as described by the social ecological model. The purpose of this manuscript is to provide a theoretical review of policy-level childhood obesity prevention nutrition initiatives informed by BE. We reviewed two policy-level approaches: (1) incentives-/price manipulation-based policies (e.g., sugary drink tax, SNAP pilot) and (2) healthful choices as defaults (Healthy Hunger Free Kids Act/National School Lunch Program, advertising regulations, default items). We review current literature as well as its limitations and future directions. Exploration of BE theory applications for nutrition policies may help to inform future theoretically grounded policy-level public health interventions.

Identifying Patterns of Alcohol Use and Obesity-Related Factors Among Emerging Adults: A Behavioral Economic Analysis

BACKGROUND

Although heavy alcohol consumption and maladaptive eating behaviors have been shown to co-occur among college students, less is known about the co-occurrence of these behaviors in a more diverse community-dwelling, emerging adult sample. The purpose of this study was to: (i) identify classes of emerging adults by their reported alcohol consumption patterns, food addiction symptoms, and body mass index; and (ii) determine whether these classes differed on indices of behavioral economic reinforcer pathology (e.g., environmental reward deprivation, impulsivity, alcohol demand).

METHOD

Emerging adult participants were recruited as part of a study on risky alcohol use (n = 602; 47% white, 41.5% Black; mean age = 22.63, SD = 1.03). Participants completed questionnaires on alcohol and food-related risk factors and underwent anthropometric assessment.

RESULTS

Latent profile analysis suggested a four-profile solution: a moderate alcohol severity, overweight profile (Profile 1; n = 424, 70.4%), a moderate alcohol severity, moderate food addiction + obese profile (Profile 2; n = 93, 15.4%), a high alcohol severity, high food addiction + obese profile (Profile 3; n = 44, 7.3%), and a high alcohol severity, overweight profile (Profile 4; n = 41, 6.8%). Individuals in Profile 1 reported significantly lower levels of environmental reward deprivation than either Profile 2 or 3, and participants in Profile 3 reported significantly higher environmental reward deprivation than those in Profile 4 (p < 0.001). Profile 4 demonstrated significantly higher alcohol demand intensity and Omax and lower demand elasticity than Profile 1, Profile 2, or Profile 3. Profile 4 also demonstrated significantly greater proportionate substance-related reinforcement than Profile 1 (p < 0.001) and Profile 2 (p = 0.004).

CONCLUSION

Maladaptive eating patterns and alcohol consumption may share common risk factors for reinforcer pathology including environmental reward deprivation, impulsivity, and elevated alcohol demand.

Vapers exhibit similar subjective nicotine dependence but lower nicotine reinforcing value compared to smokers

INTRODUCTION

E-cigarette use has increased rapidly over the last 10 years, mostly among smokers and ex-smokers. Although there may be some degree of dependency on nicotine via e-cigarette use, the nature of this dependency is poorly understood. The aim of this paper is to use tasks from behavioural economics to compare the value that smokers place on tobacco cigarettes to the value that vapers place on e-cigarettes.

METHOD

Exclusive current smokers (n = 25) and vapers (n = 20) attended one session where they completed the Cigarette/e-cigarette Dependence Scale, the Cigarette/e-cigarette Purchasing Task (CPT) and the Concurrent Choice Task (CCT). The CPT requires participants to indicate how many puffs of their chosen product they would purchase at increasing price points. The CCT requires participants to choose between earning a money point or a point towards a cigarette/e-cigarette after being presented with a neutral, money or cigarette/e-cigarette cue.

RESULTS

Overall scores on the self-report scales suggest a comparable level of dependency between smokers and vapers. The CPT revealed that vapers are more sensitive than smokers to escalating costs as consumption declined as costs increased. On the CCT, when primed with money, vapers showed a decrease in choosing e-cigarettes.

CONCLUSION

These findings suggest that, on behavioural economic tasks, tobacco cigarettes have a higher relative value than e-cigarettes. Vapers appear to place a lower limit on what they will spend to access e-cigarettes and more readily choose money over e-cigarette puffs when primed by money cues.

Behavioral Economic Demand for Alcohol and Cigarettes in Heavy Drinking Smokers: Evidence of Asymmetric Cross-commodity Reinforcing Value

INTRODUCTION

Previous studies have highlighted a strong bidirectional relationship between cigarette and alcohol consumption. To advance our understanding of this relationship the present study uses a behavioral economic approach in a community sample (N = 383) of nontreatment seeking heavy drinking smokers.

AIMS AND METHODS

The aims were to examine same-substance and cross-substance relationships between alcohol and cigarette use, and latent factors of demand. A community sample of nontreatment seeking heavy drinking smokers completed an in-person assessment battery including measures of alcohol and tobacco use as well as the Cigarette Purchase Task and the Alcohol Purchase Task. Latent factors of demand were derived from these hypothetical purchase tasks.

RESULTS

Results revealed a positive correlation between paired alcohol and cigarette demand indices (eg, correlation between alcohol intensity and cigarette intensity) (rs = 0.18-0.46, p ≤ .003). Over and above alcohol factors, cigarette use variables (eg, Fagerström Test for Nicotine Dependence and cigarettes per smoking day) significantly predicted an additional 4.5% (p < .01) of the variance in Persistence values but not Amplitude values for alcohol. Over and above cigarette factors, alcohol use variables predicted cigarette Persistence values (ΔR2 = .013, p = .05), however, did not predict Amplitude values.

CONCLUSIONS

These results advance our understanding of the overlap between cigarette and alcohol by demonstrating that involvement with one substance was associated with demand for the other substance. This asymmetric profile-from smoking to alcohol demand, but not vice versa-suggests that it is not simply tapping into a generally higher reward sensitivity and warrants further investigation.

IMPLICATIONS

To our knowledge, no study to date has examined alcohol and cigarette demand, via hypothetical purchase tasks, in a clinical sample of heavy drinking smokers. This study demonstrates that behavioral economic indices may be sensitive to cross-substance relationships and specifically that such relationships are asymmetrically stronger for smoking variables affecting alcohol demand, not the other way around.

Does Episodic Future Thinking Repair Immediacy Bias at Home and in the Laboratory in Patients With Prediabetes?

OBJECTIVE

This study aimed to determine if episodic future thinking (EFT) can decrease delay discounting (DD) among adults with prediabetes both in and out of the laboratory. DD measures how much the value of a reinforcer decreases as a function of the delay to receive it.

METHODS

Adults with prediabetes (n = 67) completed a three-session study. At session 1, baseline measures (including DD) were collected. At sessions 2 and 3, participants were prompted to engage in either EFT or control episodic thinking (CET) while completing DD and other measures. In addition, between the completion of sessions 2 and 3, participants engaged in EFT or CET at home and completed DD tasks remotely via smartphones or other Internet-connected devices.

RESULTS

Results showed significant -1.2759 (-20.24%) reductions in DD in the EFT group compared with a + 0.0287 (+0.46%) DD increase in the CET group (p = .0149) in the laboratory; and -0.4095 (-8.85%) reduction in DD in the EFT group compared with a + 0.2619 (+5.64%) increase in the CET group (p = .011) at home. Working memory (measured by Backwards Corsi and Digit Span) was found to moderate the effects of EFT on some measures of DD. EFT did not change measures from the food purchase task or a food ad libitum procedure.

CONCLUSIONS

Results show that EFT decreases DD in and out of the laboratory and supports the further exploration of EFT as an intervention for prediabetes and related chronic diseases.

CLINICAL TRIAL REGISTRATION

NCT03664726.

The condom purchase task: A hypothetical demand method for evaluating sexual health decision-making

Behavioral economic theory has proved useful for understanding the influence of delay and probability on sexual health decision-making. Demand is another principle at the intersection of microeconomics and psychology that has helped advance research relevant to health behaviors. The purpose of the present study was to develop and test a demand measure related to sexual health decision-making and the influence of sexually transmitted infection (STI) risk. Participants (N = 438) recruited using Amazon Mechanical Turk completed a commodity purchase task assessing hypothetical condom demand. Condom demand was evaluated at varied prices for use with hypothetical sexual partners that varied in STI risk. Demand was characterized by prototypic decreases in consumption with increases in cost. Higher partner STI risk was associated with greater intentions for condom-protected sex at no cost and smaller decreases in condom demand with increases in cost. Price sensitivity was also related to individual difference factors relevant to sexual health (e.g., alcohol use severity, lower STI knowledge). This study supports the utility of a condom purchase task for indexing condom valuation and capturing individual difference and contextual risk factors relevant to STI transmission. Future studies may leverage this methodology as a means to study sexual health decision-making.

Toward isolating reward changes in diet-induced obesity: A demand analysis

Although hormonal and metabolic factors are well known to influence obesity, recent evidence suggests that obesity may be influenced also by changes in reward sensitivity akin to that seen in other 'reward pathologies', like substance use disorders. The current study sought to isolate changes in reward that may occur after the onset of diet-induced obesity by characterizing the economic demand for caloric (sucrose) and non-caloric (saccharin) reinforcers in a preclinical model of diet-induced obesity (DIO). We utilized economic demand analysis to measure baseline demand intensity (Q₀) and demand elasticity (α) for sucrose and saccharin reinforcers in rats. After baseline measures were collected, rats were assigned randomly to a high-fat (HF) diet or low-fat (LF) control diet. After 8-weeks of diet exposure, HF rats were divided into obesity-resistant (OR) or obesity-prone (OP) groups based on weight after the 8-week HF diet exposure. Post-DIO demand data for each reinforcer were reassessed. At baseline, rats had higher demand intensity and lower elasticity for sucrose compared to saccharin. After 8-weeks of the high-fat diet, OP rats had significantly greater weight gain and lower demand elasticity for sucrose and saccharin and higher demand intensity for saccharin. The changes in sucrose and saccharin elasticity suggest that DIO-induced changes in food-related behavior are associated with changes in reward processes. The changes in demand intensity for saccharin suggest that demand intensity, as a measure of 'set point', is not directly linked to metabolic processes. The current study shows that microeconomic theory and demand analysis is able to isolate independent aspects of diet-induced reward changes related to caloric and non-caloric reinforcers.

Alcohol demand moderates brief motivational intervention outcomes in underage young adult drinkers

INTRODUCTION

The Alcohol Purchase Task (APT), a behavioral economic measure of alcohol's reinforcing value (demand), has been used to predict the effects of Brief Motivational Intervention (BMI) on alcohol use outcomes. However, it is not known whether BMI may be more or less efficacious, relative to control, among those with different levels of alcohol demand prior to treatment.

METHODS

Non college-attending young adults (N = 150) reporting past-month heavy drinking were randomized to a single in-person session of BMI or a relaxation training control (REL). The BMI included delivery of personalized feedback and focused on developing discrepancy between the young adults' goals and their current pattern of alcohol use. At baseline, participants completed assessments of alcohol use and the APT. Drinking levels were re-assessed at 6 weeks and 3 months post-intervention. Demand indices derived from the APT were examined as moderators of treatment effects on follow-up drinking after covarying for baseline alcohol use.

RESULTS

Two of four APT demand indices - intensity and Omax - moderated treatment outcomes. Relative to REL, BMI led to greater reductions in total number of drinks consumed and drinks per drinking day among participants with higher baseline alcohol demand. This association was not observed among participants with lower levels of alcohol demand.

CONCLUSIONS

These results demonstrate that BMI may be particularly beneficial for those with a high reinforcing value of alcohol. The mechanism for this effect is unclear, and determining the process by which BMI confers increased benefit for these individuals is a fruitful area for future work.

Evaluating non-medical prescription opioid demand using commodity purchase tasks: test-retest reliability and incremental validity

RATIONALE

Non-medical prescription opioid use and opioid use disorder (OUD) present a significant public health concern. Identifying behavioral mechanisms underlying OUD will assist in developing improved prevention and intervention approaches. Behavioral economic demand has been extensively evaluated as a measure of reinforcer valuation for alcohol and cigarettes, whereas prescription opioids have received comparatively little attention.

OBJECTIVES

Utilize a purchase task procedure to measure the incremental validity and test-retest reliability of opioid demand.

METHODS

Individuals reporting past year non-medical prescription opioid use were recruited using the crowdsourcing platform Amazon Mechanical Turk (mTurk). Participants completed an opioid purchase task as well as measures of cannabis demand, delay discounting, and self-reported pain. A 1-month follow-up was used to evaluate test-retest reliability.

RESULTS

More intense and inelastic opioid demand was associated with OUD and more intense cannabis demand was associated with cannabis use disorder. Multivariable models indicated that higher opioid intensity and steeper opioid delay discounting rates each significantly and uniquely predicted OUD. Increased opioid demand intensity, but not elasticity, was associated with higher self-reported pain, and no relationship was observed with perceived pain relief from opioids. Opioid demand showed acceptable-to-good test-retest reliability (e.g., intensity rxx = .75; elasticity rxx = .63). Temporal reliability was lower for cannabis demand (e.g., intensity rxx = .53; elasticity rxx = .58) and discounting rates (rxx = .42-.61).

CONCLUSIONS

Opioid demand was incrementally valid and test-retest reliable as measured by purchase tasks. These findings support behavioral economic demand as a clinically useful measure of drug valuation that is sensitive to individual difference variables.

Using behavioral economic variables to predict future alcohol use in a crowdsourced sample

BACKGROUND

Theoretical perspectives at the intersection of behavioral economics and operant theory have resulted in numerous advances for addiction science. Three mechanisms (i.e. behavioral economic demand [consumption-price relationships], delay discounting [reinforcer devaluation with delay], and proportionate alcohol-related reinforcement [relative reinforcement attributable to alcohol]) are proposed to contribute to problematic alcohol use. Limited research has evaluated the unique contribution of these mechanisms for predicting future alcohol consumption.

AIM

The purpose of this study was to evaluate the predictive relationship between these mechanisms and self-reported alcohol use frequency, quantity, and severity.

METHODS

Participants (n=223) sampled from the crowdsourcing website Amazon Mechanical Turk completed a survey containing behavioral economic measures. Weekly reports of daily alcohol use were then collected for 18 weeks. Unadjusted and adjusted models determined the association between behavioral economic variables and alcohol use.

RESULTS/OUTCOMES

Behavioral economic measures were associated with alcohol and soda use at baseline in a stimulus-selective manner (e.g. alcohol demand associated with alcohol, but not soda, variables). Predictive models adjusted for Alcohol Use Disorder Identification Test scores indicated that increased proportionate alcohol-related reinforcement and behavioral economic demand were uniquely and incrementally associated with frequency (e.g. adjusted odds ratio (AOR)=5.54 for proportionate alcohol-related reinforcement, p<0.05) and quantity-severity measures (e.g. AOR=7.58 for alcohol demand intensity, p<0.001), respectively. Test-retest reliability was generally acceptable (r_xx=0.42-0.76) with the exception of proportionate alcohol-related reinforcement (r_xx=0.29).

CONCLUSION/INTERPRETATION

These findings indicate the unique, predictive, and incremental validity of behavioral economic measures for evaluating future alcohol consumption, supporting their continued use in addiction science research.

Contribution of cannabis-related cues to concurrent reinforcer choice in humans

BACKGROUND

Drug-related cues play a critical role in the development and persistence of substance use disorder. Few human laboratory studies have evaluated how these cues contribute to decisions between concurrently presented reinforcers, and none have examined the specific role of cannabis cues. This study evaluated the contribution of cannabis-related cues to concurrent monetary reinforcer choice in humans.

METHODS

Participants with a cannabis use history (i.e., use in the past two weeks and 50 or more lifetime uses; n = 71) and controls without this history (i.e., 5 or less lifetime uses; n = 79) were recruited using Amazon Mechanical Turk. A cued concurrent choice task was used in which cannabis trials presented two cues (one cannabis and one neutral) side-by-side followed by concurrent monetary offers below each image. The primary dependent measure was choice for cannabis-cued monetary reinforcers on equal value trials. Secondary analyses evaluated individual difference variables related to choice bias.

RESULTS

Participants in the cannabis group showed a significant bias for cannabis-cued choices (mean 76.0%) whereas participants in the control group showed a significant bias against cannabis-cued choices (mean 30.3%). Reaction times on cannabis trials were faster than neutral filler trials and did not differ by group. Cannabis-cued choice was significantly associated with more frequent cannabis use (r = .44), higher cannabis demand intensity (r = .28), and lower cannabis elasticity (r = -.30).

CONCLUSIONS

These findings suggest that cannabis-related cues can influence reinforcer choice and potentially promote disadvantageous decision-making related to non-drug reinforcers.

Validation of a brief behavioral economic assessment of demand among cigarette smokers

Basic and clinical addiction research use demand measures and analysis extensively to characterize drug use motivations. Hence, obtaining an accurate and brief measurement of demand that can be easily utilized in different settings is highly valued. In the current study, 2 versions of a breakpoint measure, designed to capture cigarette demand, were investigated in 119 smokers who were recruited from an online crowdsourcing platform. The first version determines the maximum price a smoker is willing to pay for one cigarette received right now when paid out of pocket, and the second determines the maximum price when paid using a hypothetical $100 gift card received for free. The breakpoint measures were administered along with the Cigarette Purchase Task (CPT), Fagerström Test for Cigarette Dependence (FTCD), and The Questionnaire of Smoking Urges (QSU-brief). Both single-item breakpoint versions were significantly correlated with CPT-derived demand measures loaded on the persistence factor (i.e., elasticity of demand, breakpoint, Pmax, and Omax), but not with those loaded on the amplitude factor (i.e., intensity of demand). In addition, both single-item measures were associated with metrics of tobacco dependence (e.g., FTCD, QSU) with effect sizes that are similar to the ones found between CPT-derived breakpoint and those same metrics. These findings suggest that the single-item breakpoint measure is a viable method for measuring demand that may provide a useful and efficient tool to capture crucial and distinct aspects of smoking. In addition, the breakpoint measures may help increase the utility of behavioral demand measures in novel research and clinical settings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The Demand Curve Analyzer: Behavioral economic software for applied research

Free and open-source software for applying models of operant demand called the Demand Curve Analyzer (DCA) was developed and systematically evaluated for use in research. The software was constructed to streamline the use of recommended screening measures, prepare suitable scaling parameters, fit one of several models of operant demand, and provide publication-quality figures. The DCA allows users to easily import price and consumption data into spreadsheet-based controls and to perform statistical modeling with the aid of a graphical user interface. The results from computer simulations and reanalyses of published study data indicated that the DCA provides results consistent with commercially available software that has been traditionally used to apply these analyses (i.e., GraphPadTM Prism). Further, the DCA provides additional functionality that other statistical packages do not include. Practical issues and future directions related to the determination of scaling parameter k, screening for nonsystematic data, and the incorporation of more advanced behavioral economic methods are also discussed.

Intermittent, extended access to preferred food leads to escalated food reinforcement and cyclic whole-body metabolism in rats: Sex differences and individual vulnerability

Compulsive binge eating is a hallmark of binge eating disorder and bulimia nervosa and is implicated in some obesity cases. Eating disorders are sexually dimorphic, with females more often affected than males. Animal models of binge-like eating based on intermittent access to palatable food exist; but, little is known regarding sex differences or individual vulnerability in these models with respect to the reinforcing efficacy of food, the development of compulsive- and binge-like eating, or associated changes in whole-body metabolism or body composition. Adolescent male (n = 24) and female (n = 32) Wistar rats were maintained on chow or a preferred, high-sucrose, chocolate-flavored diet in continuous or intermittent, extended access conditions. Body weight and composition, intake, fixed- and progressive-ratio operant self-administration, and whole body energy expenditure and respiratory exchange ratios were measured across an 11-week study period. Subgroup analyses were conducted to differentiate compulsive-like "high responder" intermittent access rats that escalated to extreme progressive-ratio self-administration performance vs. more resistant "low responders." Female rats had greater reinforcing efficacy of food than males in all diet conditions and were more often classified as "high responders". In both sexes, rats with intermittent access showed cycling of fuel substrate utilization and whole-body energy expenditure. Further, "high-responding" intermittent access female rats had especially elevated respiratory exchange ratios, indicating a fat-sparing phenotype. Future studies are needed to better understand the molecular and neurobiological basis of the sex and individual differences we have observed in rats and their translational impact for humans with compulsive, binge eating disorders.

Less is more: Negative income shock increases immediate preference in cross commodity discounting and food demand

Negative income shock, or the rapid reduction in financial stability, has previously been shown to increase impulsive choice for money and demand for fast food. The interplay of these conditions for obesity is called reinforcer pathology. The present work examines the impact of negative income shock on monetary and fast food discounting using a cross-commodity delay discounting task and on purchasing of fast food and an alternative commodity. An obese sample (n = 120) was recruited from Amazon Mechanical Turk and assigned to read one of two narratives: negative income shock (n = 60) or control (n = 60). Participants then completed both within- and cross-commodity discounting tasks of money and food, and purchase tasks for fast food and bottled water. The negative income shock group demonstrated greater impulsive choice across discounting tasks, as well as higher intensity of demand for fast food but not for a non-caloric control commodity (bottled water). These results suggest that negative income shock increases preference for immediate reinforcement regardless of commodity type (money or fast food), but has specific effects increasing demand for particular commodities (fast food but not an alternative). In a reinforcer pathology framework, negative income shock increasing discounting of the future while increasing demand for fast food specifically represents a high-risk state for negative health behavior in obesity.