Inducing select/reject control in a matching-to-sample procedure with observing response: Effects on stimulus equivalence
This study investigated a three-choice matching-to-sample procedure with an observing-response requirement to induce select and reject control during baseline training and examined their effects on the formation of equivalence classes. The study involved four girls, aged 8 to 10 years, who participated in a computer-based task that alternated between conditions designed to induce select and reject control by requiring observing responses to display the stimuli. In the select-control condition, the correct stimulus was revealed first on at least 75% of the trials, increasing the likelihood of selecting the correct stimulus without seeing the incorrect ones. In contrast, in the reject-control condition, the correct stimulus was revealed third on at least 75% of the trials, forcing the display of both incorrect stimuli. This procedure successfully generated both select and reject control, which increased progressively with the accuracy during baseline training trials. Select control was more prominent than reject control, but both led to the formation of equivalence classes. This finding suggests that reject control does not hinder control by the correct stimulus.
Application of synchronous music reinforcement to increase walking speed: A novel approach for training intensity
Walking is a common and preferred form of exercise. Although there are current recommendations for walking volume (e.g., steps per day), recent research has begun to distinguish volume from intensity (e.g., "brisk" walking) as an important dimension of exercise. Increasing intensity may confer health advantages beyond volume measures because it shifts cardiovascular performance to more vigorous training zones. Reinforcement-based approaches have been valuable in increasing volume measures of exercise, and the present study sought to develop a corresponding reinforcement approach to training walking intensity. For this study, we used a continuous reinforcement paradigm where music played only while walking met specified criteria; otherwise, music playback stopped. As a result, music was synchronized with walking performance. Seventeen participants walked on a nonmotorized treadmill at a self-selected pace. Across the session, different conditions arranged for music to play independent of walking speed or contingent on speed increases or decreases. An extinction component assessed performance when music was withdrawn completely. Walking speed was selectively increased and decreased by adjusting the contingencies that were arranged for music, and variability in speed increased during extinction, with both findings indicating that music was a reinforcer. Heart rate was also increased to moderate-vigorous intensities during reinforcement. The findings provide a compelling case that walking intensity can be modified by music reinforcement. We suggest that synchronous schedules may be an important foundation for future exercise technologies that are based on reinforcement.
Social discounting in a symmetric giving and taking frame: An artifactual field experiment with young South African adults
In the dictator game, the evidence that giving is equivalent to taking is mixed. The purpose of this study was to investigate framing effects (giving/taking) on social-discounting rates among young African adults from an informal settlement in South Africa. Employing a within-participant design, these young adults completed a series of incentivized dictator games with an isomorphically equivalent giving and taking frame at each of eight social distances. Altruism was measured by the social-discounting rate, and framing effects were assessed using generalized linear regression. The study provides empirical evidence that prosocial behavior among young South African adults is subject to framing because exponential, hyperbolic, and q-exponential social-discounting rates in all instances were lower in the taking than in the giving frame. This difference may be the result of greater "egalitarianism" and "selflessness" elicited by the taking frame, which likely is a product of the experiment's particular social and economic field context. More comparative research is required to establish the working of specific mechanics of morality that may operate differently in diverse socioeconomic contexts, thus contributing to elucidating the heterogeneous nature of findings in this area of study.
Willingness to wait outperforms delay discounting in predicting drinking severity
Alcohol misuse ranks among the leading causes of preventable death worldwide. Therefore, discovering measures that can predict hazardous drinking is critical. The delay discounting paradigm-which assesses relative preference for immediate rewards over larger, later rewards-has frequently been used as a proxy for impulsive choice, but it does not capture how long someone is willing to wait for delayed rewards when the arrival time is uncertain. In contrast, a newer willingness-to-wait task measures how long someone is willing to wait for a delayed reward of uncertain timing before giving up. We hypothesized that performance in this willingness-to-wait task would be associated with drinking severity and that this task may even outperform delay discounting as a predictor of drinking severity. We pooled data from multiple studies of mostly college-aged adult participants. Drinking severity was assessed with the Alcohol Use Disorders Identification Test. Willingness to wait under temporal uncertainty, but not delay discounting, was associated with severity of alcohol problems among participants who drank (n = 212). Individuals engaging in hazardous drinking were less willing to wait for rewards when delays were unknown than were individuals with low-risk drinking habits. Thus, willingness to wait under temporal uncertainty may be an important predictor of problematic drinking.
Discrimination of highly similar stimuli as members of different equivalence classes
Learning to discriminate between physically similar stimuli as members of different classes can be relevant in certain situations. This study investigated effective methods of displaying two pairs of quasi-identical stimuli, as samples and/or comparisons, during the training of baseline conditional discriminations. The goal was to enable participants to form three 3-member equivalence classes and discriminate similar stimuli as members of distinct equivalence classes. Eighteen adults underwent arbitrary relations (AB/AC) training. A multiple-probe design assessed maintenance and emergence of stimulus relations. Participants were randomly assigned to one of six training conditions across three experiments. Conditions 1, 2, and 5 presented quasi-identical stimuli successively as samples during training. Condition 3 presented quasi-identical stimuli successively as comparisons, whereas Condition 4 presented quasi-identical stimuli simultaneously as comparisons. Condition 6 presented each pair of quasi-identical stimuli simultaneously as a sample and a comparison. Condition 4 uniquely resulted in successful equivalence class formation for all participants. Conditions 3 and 6 failed to form equivalence classes, whereas Conditions 1, 2, and 5 did not yield baseline learning. These findings highlight the relevance of presenting quasi-identical stimuli as simultaneous comparisons (Condition 4) to foster equivalence class formation. Understanding optimal training conditions has implications for discussions on the acquisition of simple discriminations required in training simultaneous conditional discriminations.
Ecological momentary assessment of delay discounting, reward valuation, and craving in very light cigarette users
Heightened delay discounting has been linked to adverse smoking cessation outcomes, including among light cigarette users. Few studies have evaluated delay discounting's proposed mechanism, preference reversal (concurrent increases in valuation of/craving for desired objects), and none have done so in naturalistic settings. We examined how person-level delay discounting moderated the within-person association between cigarette valuation and craving among very light daily cigarette users who were financially incentivized to abstain. Forty participants completed a baseline delay-discounting task and intermittent ratings of cigarette valuation and craving during the incentivized abstinence attempt. Subjects earned monetary rewards for abstinence on a descending schedule (e.g., $20 on Days 1 and 2 and $2.50 on Days 9 and 10). Consistent with preference reversals, there was a positive association between cigarette valuation and craving. This relation was moderated by delay discounting (stronger among those with low discounting rates) and by monetary reinforcement amount (stronger on days with low reinforcement). Additionally, subjects were more likely to report stronger cravings on days with high monetary reinforcement, with this effect moderated by delay discounting (stronger among those with low discounting rates). The results suggest that heightened delay discounting may not confer risk for preference reversal among very light daily cigarette users who are attempting abstinence.
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.
Experience with reduced-nicotine cigarettes and whether this decreases smoking and substitution for full-nicotine cigarettes
Studies suggest that reduced-nicotine cigarettes decrease nicotine intake and dependence. However, questions remain about reduced-nicotine cigarette abuse liability, whether reduced-nicotine cigarette exposure lowers reduced- and full-nicotine cigarette use, and whether reduced-nicotine cigarettes substitute for full-nicotine cigarettes. This randomized, double-blind laboratory study used operant behavioral economics to examine abuse liability of cigarettes with varying nicotine content. Non-treatment-seeking smokers (N = 43) self-administered reduced- (5.2, 2.4, or 1.3 mg/g) and full-nicotine (15.8 mg/g) cigarettes before and after 3 weeks of at-home exposure. Participants were randomized to full-nicotine or one of the reduced-nicotine cigarettes to determine the effect of exposure on abuse liability and substitutability. Abuse liability was assessed in single-commodity sessions, and substitutability was measured in concurrent-commodity sessions. In the self-administration sessions, concurrently available reduced-nicotine cigarettes attenuated full-nicotine cigarette demand and rendered reduced-nicotine cigarettes partial substitutes for full-nicotine cigarettes. Exposure to study cigarettes for 3 weeks marginally reduced demand for reduced- and full-nicotine cigarettes irrespective of nicotine content. Results suggest a limited influence of nicotine content on smoking behavior in established smokers and highlight the role of nonpharmacological factors (e.g., taste/smell) on the maintenance of smoking. These results should be considered in determining whether a nicotine-reduction standard is a feasible path for reducing cigarette demand.
Zoographics in the Journal of the Experimental Analysis of Behavior: Increasing inclusion of female animals
We examined the zoographics, or the characteristics of nonhuman animal subjects, reported for the entirety of the Journal of the Experimental Analysis of Behavior (JEAB) through the most recent complete year (1958-2023). Animal sex in particular was evaluated to determine whether the lack of inclusion of female subjects in other disciplines extends to JEAB. Through systematic coding of all nonhuman empirical articles, we found consistent underreporting of most zoographics and a disproportionate use of male subjects relative to female subjects. Additionally, animal sex was commonly unreported and the inclusion of both male and female subjects was sparse. Recent years show some improvement, but greater inclusion is required. Lack of female subjects in research as well as underreporting of zoographics can generate unrepresentative results and hamper replication, generalization, and translation. We provide resources to guide future research and reporting suggestions such as equal inclusion and disaggregation of data by sex. We also clarify misunderstandings about the use of both sexes in research such as beliefs that it necessarily increases the cost of research.
Resurgence in a discrete-trial procedure in rats
Resurgence is a transient recovery of a previously extinguished target response following a worsening of reinforcement conditions for an alternative response. Laboratory studies with nonhuman animals typically assess resurgence in free-operant situations where subjects can freely emit responses. The purpose of the current study was to investigate whether resurgence would be observed in a discrete-trial procedure where only a single response could occur in each trial, using rats as subjects. The experiment consisted of three phases, and each session ended after 200 trials. All trials began with the insertion of target and alternative levers and ended once a response was emitted. In Phase 1, both target and alternative responses were reinforced with a probability of .25. In Phase 2, the target response was extinguished while still reinforcing the alternative response with a probability of .25. Finally, resurgence was tested by placing the alternative response on extinction. All rats showed robust resurgence in this highly constrained discrete-trial situation. We also found that the latencies of resurged target responses differed from those in Phase 1. Overall, the present discrete-trial procedure could produce reliable resurgence as with typical free-operant procedures and has several potential benefits for studying resurgence.
Time perception and delay discounting in the FMR1 knockout rat
There is substantial evidence for timing (time perception) abnormalities related to developmental disabilities, particularly autism spectrum disorder. These findings have been reported in humans and nonhuman preclinical models. Our research objective was to extend that work to a genetic knockout (KO) model of fragile X/developmental disability, the FMR1 KO rat. We also sought to test delay discounting in the model and assess potential relations between timing and choice behavior. Consistent with previous human and nonhuman work, we found reduced timing precision in the FMR1 KO rats. We also discovered significantly increased smaller, sooner reward choice in the FMR1 KO rats. Performance on the timing task appeared to be unrelated to performance on the choice task for both model and control rats. These results add to what has become increasingly clear: timing is disrupted in humans diagnosed with developmental disabilities and in nonhuman models designed to model developmental disabilities. Our findings are consistent with those of previous work and the first to our knowledge to show such effects in the FMR1 KO rat. We discuss the potential clinical implications and future directions surrounding potential "timing interventions" for individuals diagnosed with developmental disabilities.
Reward deprivation is associated with elevated alcohol demand in emerging adults
Policies vary substantially in terms of providing sources of psychosocial enrichment. Behavioral economic models of substance use and addiction emphasize that deficits in access to substance-free sources of reward increase substance reinforcing value and risk for addiction. The current study used an alcohol demand curve approach to test the hypothesis that various indices of reward deprivation would be associated with elevated alcohol reinforcing efficacy. We examined associations between alcohol demand indices and several facets of reward deprivation in a sample of young adults (N = 1,331; ages 19-25 years) recruited from the United States and Canada who reported recent binge drinking. Additionally, we created an index of cumulative reward deprivation that integrated the various reward facets and examined its association with alcohol demand intensity and maximum expenditure on alcohol. Our findings indicate that reward deprivation is associated with elevated alcohol demand and provide support for alcohol prevention and intervention approaches that emphasize environmental enrichment.
Correction to "The generalization-across-dimensions model applied to conditional temporal discrimination"
Evaluation of resurgence following differential reinforcement of alternative behavior with and without extinction in a human operant model
One of the most common treatments for severe challenging behavior involves placing the challenging behavior on extinction and differentially reinforcing an alternative response (DRA). However, extinction is not always feasible and may be unsafe or impractical to implement in some circumstances. Thus, implementing a DRA without extinction intervention may be necessary for some cases. Currently, the extent to which DRA without extinction produces durable treatment outcomes, particularly as it relates to the resurgence of challenging behavior, is unclear. The present study investigated resurgence following DRA with and without extinction using a three-phase resurgence evaluation in a translational human operant model with college students as participants. All participants demonstrated resurgence across both experimental groups. Although there were no statistically significant differences in the prevalence, magnitude, or persistence of resurgence between groups, levels of resurgence magnitude were relatively higher in the DRA-without-extinction group than in the DRA-with-extinction group. Clinical implications of these findings and directions for future human operant investigations of resurgence are discussed.
Understanding resurgence and other emergent activity with the laws of allocation, induction, and covariance
Resurgence is defined as an increase in a previously extinguished target response (B) resulting from the worsening of conditions for a more recently reinforced alternative response (B). Worsening includes extinction or reductions in rate, amount, and immediacy of delivery of food or some other phylogenetically important event (PIE). In the first part of the article, we apply the laws of allocation, induction, and covariance to understand not only resurgence of operant activity previously covarying with the PIE (B) but also a constellation of ontogenetic and phylogenetic activities both related to the PIE (B) and unrelated to the PIE (B). In the second part, we discuss how induction might be incorporated into and provide alternative processes within an existing matching-based framework, resurgence as choice (RaC). We begin to identify how this range of activities could depend on changes in the relative competitive weight (V) of all available activities (B, B, B, B) in addition to only those receiving explicit training (B, B). Future empirical and theoretical research is needed within this framework to provide a more complete understanding of resurgence and behavior more generally.
Avoidance of hot air blast in Rattus norvegicus
The hegemonic use of electric shock as an aversive stimulus limits what is known about the generality of avoidance behavior and related phenomena. The purpose of this study was to investigate the effects of using the hot air blast (HAB) instead of electric shock as an aversive stimulus in avoidance conditioning. Four male Wistar rats were exposed to a discrete-trial procedure. In the first phase, the emission of a lever-press response during a trial was positively reinforced. In the second phase, the same contingency was employed, but an escapable HAB was presented at the end of a trial when no response was emitted. In the third phase, positive reinforcement was suspended and a discrete-trial avoidance procedure was employed. In the fourth phase, HAB presentation was completely suspended. As a result, all subjects learned the avoidance response and showed a marked reduction in its frequency during HAB suspension. These results offer evidence indicating that avoidance behavior is controlled by the HAB, thereby advancing the understanding of the generality of this stimulus as being aversive.
Influence of amount and delay of reward on choice and response rate: A free-operant, multiple-schedule analogue of a discrete-trial procedure
The current study explored a free-operant analogue of discrete-trial procedures to study the effects of amount and delay of reinforcement on choice and response rate. Rats responded on a multiple variable-interval (VI) 45-s, 45-s schedule, with interspersed choice probe trials. Comparison of relative response rates and percentage of choice revealed some discrepancies between the free-operant analogue and discrete-trial procedures. Amount of reward controlled choice behavior when the ratios of delays were similar. When reward delays were more discrepant, delay length controlled choice behavior. Whereas the percentage of choice was larger for the larger magnitude reward, the relative rate of response for the larger magnitude was less than .50. In contrast, when the percentage of choice generally fell to below 50% (with large amount and large delay differences between alternatives), relative response rate indicated a preference for the larger amount alternative. This study shows the feasibility and utility of a free-operant analogue of discrete-choice studies that could be used to develop an analysis of preference.
Using sign tracking to experimentally increase self-control in rats
Impulsive choice describes a preference for a smaller-sooner reward (SSR) over a larger-later reward (LLR). A large body of research has examined different procedures for decreasing impulsive choice in nonhuman subjects. One limitation of these procedures is the extensive training duration required to achieve the desired results. To address this limitation, the current experiment examined the effects of a brief course of Pavlovian training, designed to establish a conditioned stimulus (CS) that could be strategically used to encourage LLR choices. Forty male Long-Evans rats were randomly assigned to appetitive Pavlovian or unpaired training. A lever insertion signaled an upcoming unconditioned stimulus (i.e., food presentation) for Pavlovian rats and it acquired CS properties. The lever was uncorrelated with the US in the unpaired group, and it did not acquire CS properties. In the subsequent impulsive-choice assessment, the lever from the training phase served as the lever rats pressed to choose the LLR. After an LLR choice, the lever remained in the chamber during the delay to the LLR, just as the SSR lever remained in the chamber until that reward was delivered. Pavlovian-trained rats sign tracked toward the lever CS and made significantly fewer impulsive choices than did rats in the unpaired group.
The effects of simultaneous point gains and losses on human persistence
Four experiments assessed the effects of simultaneous point gains and losses on human responding on a moving response button. Experiments 1 and 2 examined the effects of point loss arranged in variable-time (VT) and variable-interval (VI) schedules on persistence. For that purpose, a multiple schedule was in force. One component had point gains only, and the other had point gains and losses. The net reinforcement rate was equated across components by arranging greater point gains in the gains-plus-losses component. Increases in the speed of the moving response button disrupted responding during test sessions. No differential persistence between point-gains and point-gains-and-loss conditions was observed during Experiments 1 and 2. To ensure that point losses could function as punishers, Experiments 3 and 4 compared the effects of point loss arranged in fixed-ratio (FR) or VI schedules on response rate and persistence. The FR and VI point loss decreased the response rate during Experiment 3 but did not produce differential persistence in Experiment 4. These results suggest that point loss decreases response rate but does not weaken persistence more than gains strengthen persistence.
Exploring the suitability of cannabis use with next-day responsibilities: A behavioral-economic and qualitative study
Cannabis demand is sensitive to next-day responsibilities, such as job interviews; however, it is unclear how demand is affected by non-work-related responsibilities and how reported compatibility of cannabis use (i.e., how suitable one perceives cannabis use to be in a situation) influences demand. This study examined the effects of a range of responsibilities on cannabis demand in a crowdsourced sample of adults who smoked cannabis at least monthly (n = 177; 78% White; 47% women; mean age = 36.52). Participants completed hypothetical marijuana purchase tasks asking how much cannabis they would consume at escalating prices in the context of no responsibilities and next-day responsibilities spanning work, leisure, and caregiving. Cannabis demand was significantly reduced in all responsibility conditions (ps < .008; ds .28-.94), with the largest reductions for the job interview and caring-for-kids conditions. Higher ratings of suitability of cannabis use in each situation were correlated with higher demand. Finally, a qualitative thematic analysis characterized why cannabis use was considered suitable or unsuitable with each responsibility. These results suggest that demand is sensitive to next-day responsibilities. However, these effects are not uniform, and future research is needed to examine these individual differences and the timing of upcoming responsibilities.