Buscador de artigos científicos

Operant demand and public health

Ano: 2025

Optimizing variables for contingency management among infant caregivers using a simulated purchase task

Ano: 2025

Abstract Behavioral economics offers a framework for understanding choice making around public health concerns such as drug use and distracted driving. Such a framework could be beneficial to understanding caregiver choices related to arranging an infant sleep environment. Nonadherence to infant sleep safety guidelines provided by the American Academy of Pediatrics increases the risk of sleep‐related infant deaths. The present study adopted a willingness‐to‐accept purchase task procedure, used in previous research to evaluate variables that predict abstaining from consuming alcohol, to evaluate intention to adhere to recommendations for arranging a safe infant sleep environment. This analysis would inform contingency management incentive scales used to measure caregiver adherence following training caregivers to arrange an infant sleep environment and identify variables that might predict treatment engagement. The results identified incentive sizes, condition duration, and participant variables that predict caregiver adherence. The results can be applied to future investigations that train caregivers to arrange an infant sleep environment.

Pairs of rats cooperate more when responding to simultaneous reinforcement than to alternated reinforcement

Ano: 2025

Abstract The purpose of this experiment was to explore whether simultaneous access to consequences configures a defining functional feature of coordination. We evaluated whether coordination episodes are maintained when reinforcers are alternately presented to two cooperating rats across these episodes, in contrast to the delivery of reinforcers simultaneously for both rats and independently for each rat. Rat pairs responded under either a tandem fixed‐interval (FI) 10‐s FI 10‐s or a tandem variable‐interval (VI) 10‐s VI 10‐s schedules. In the baseline, lever presses of each rat were individually reinforced according to the tandem FI FI schedule. In two simultaneous reinforcement conditions, reinforcer deliveries depended on coordination episodes under either tandem schedule. In two alternated reinforcement conditions, rats accessed reinforcers in alternation under either tandem schedule. Two main findings are reported: (1) proportions of coordination were consistently higher under the simultaneous than under the alternated reinforcement condition regardless of the type of tandem schedules (FI or VI) and (2) proportions of coordination were similar in the individual and alternated reinforcement conditions. Although the obtained reinforcement rates limit a conclusive evaluation, these findings indicate that the simultaneous delivery of reinforcers (mutual reinforcement) is a critical variable in the operant selection of coordinated responding.

Patterns of HIV viral suppression in a clinical trial evaluating a contingency management intervention

Ano: 2025

Abstract The HIV/AIDS epidemic remains a global health challenge. This secondary analysis evaluated time‐course effects of a contingency management intervention designed to improve antiretroviral therapy (ART) adherence and sustained HIV viral suppression. Participants were randomized to a usual care or an incentive group. Incentive participants could earn monetary incentives for submitting blood samples with reduced or undetectable HIV viral loads. A thinning procedure gradually reduced testing and reinforcer delivery frequency for participants who consistently met reinforcement criteria. Over the 2‐year intervention period, the incentive group demonstrated significantly shorter times to viral suppression and significantly longer durations of sustained suppression and maintained undetectable viral loads even as testing intervals increased. Engagement in the intervention correlated strongly with treatment success. These findings illustrate the potential of adaptive, reinforcement‐based strategies to enhance ART adherence, sustain HIV viral suppression, inform scalable interventions for HIV care, and contribute to ending the HIV/AIDS epidemic.

Perceived reward certainty in the assessment of delay discounting

Ano: 2025

Abstract Reward delays are often associated with reduced probability of reward, although standard assessments of delay discounting do not specify degree of reward certainty. Thus, the extent to which estimates of delay discounting are influenced by uncontrolled variance in perceived reward certainty remains unclear. Here we examine 370 participants who were randomly assigned to complete a delay discounting task when reward certainty was either unspecified ( n =184) or specified as 100% ( n = 186) in the task trials and task instructions. We examined potential group differences in (a) perceived reward certainty across a range of delays, (b) delay discounting, and (c) associations between perceived reward certainty and delay discounting. Delay significantly reduced perceived reward certainty in both groups, although delay did not significantly interact with group to affect perceived certainty. Despite higher perceived reward certainty in the specified group, no significant group difference in delay discounting was observed. Higher perceived reward certainty was associated with lower delay discounting in both groups. However, we found no evidence that specifying reward certainty influences estimates of delay discounting. Future research should examine whether perceived reward certainty moderates associations between delay discounting and health behavior and whether perceived reward certainty is impacted by interventions that change delay discounting.

Performance of younger and older adults on a bidirectional naming assessment

Ano: 2025

Abstract In research on variables that influence bidirectional naming, measurement of bidirectional naming often involves exposing children to pairs of verbal and visual stimuli, followed by testing of listener behavior and tacts. We administered a bidirectional naming assessment, modeled after an assessment procedure described in previous studies, to 12 younger adults (18 to 25 years) and 12 older adults (67 years and older). Visual patterns were paired with nonsense words, and listener behavior and tacts were tested after a 2‐hr delay. The assessment classified one participant in the younger group and no participants in the older group as meeting criteria for incidental bidirectional naming and only four additional participants (all in the younger group) as meeting criteria for unidirectional naming. Although adults should theoretically be expected to demonstrate advanced bidirectional naming, the assessment procedure failed to capture this repertoire. The results suggest that below‐criterion performance in bidirectional naming assessment may in some cases be an artifact of assessment, instead of suggesting a bidirectional naming repertoire has not been acquired. These findings have implications for measuring bidirectional naming and interpreting assessment outcomes.

Peter Urcuioli's lasting contribution: Animal memory research and an important model of stimulus class formation

Ano: 2025

Abstract My collaboration with Peter Urcuioli started with research on delayed matching to sample. Initially we asked, what do pigeons remember during the delay in delayed matching to sample: a retrospective coding of the sample or a prospective coding of the comparison‐related response? This led us to examine the basis of the differential outcomes effect. Why are samples associated with differential outcomes learned faster and remembered better than samples associated with common outcomes? This research helped us discover a procedure that resulted in functional stimulus equivalence: Samples associated with the same comparison are commonly associated. This research led Peter to develop his creative model of pigeon equivalence class formation. His model predicts the conditions under which pigeons satisfy the three components of what is known as Sidman equivalence : reflexivity, symmetry, and transitivity, phenomena that are difficult to demonstrate in pigeons. Importantly, his model predicts the opposite of reflexivity ( anti‐reflexivity ) and symmetry ( anti‐symmetry ). Research confirming Peter's model laid to rest the belief that the emergent relations defining Sidman equivalence can be satisfied only by an organism capable of using language. In his long career, Peter Urcuioli has made an important and long‐lasting contribution to the field of learning and comparative cognition.

Pigeons' performance in the number‐left task: Associative or computational mechanism?

Ano: 2025

Abstract This study investigates the mechanisms that underlie pigeons' performance in the number‐left task. After producing x light flashes, pigeons had to choose between a standard option that delivered reinforcement after a fixed number of additional flashes, S = 4, and a number‐left option that delivered reinforcement after a variable number of additional flashes, L = 8 − x . In Experiment 1, pigeons were trained with forced and choice trials with 1 ≤ x ≤ 7. During testing, the number of choice trials was simply increased. In Experiment 2, pigeons were trained only with the anchor numerosities x = 1 and x = 7 and during testing unreinforced probe trials introduced the intermediate numerosities, x = 2, 3, 4, 5, and 6. Performance was similar in both experiments and consistent with a computational mechanism. To test whether performance in the previous experiments was due to the substantial overlap in the induced generalization gradients around the anchor numerosities, in Experiments 3a and 3b, we selected anchor numerosities that were farther apart ( x = 5 and x = 50, with S = 12 and L = 53 − x ). Yet, pigeons' performance remained similar. We discuss the implications of these findings for the mechanisms that underlie numerosity discrimination.

Polydrug abuse: Choice between drugs as a function of concurrent nonindependent ratio sizes

Ano: 2025

Abstract Polydrug abuse is the persistent self‐administration of more than one reinforcing drug. The present study provided rhesus monkeys concurrent access to two drugs: 8% alcohol and solutions of either cocaine or methadone. The liquids were available under concurrent nonindependent fixed‐ratio (FR) schedules across increasing and then decreasing ratio sizes. These schedules generate high rates of changeover responses and yield a dependent variable of responses per delivery that is not rigidly tied to the ratio‐schedule value. The programmed schedule size was equal for both liquids and increased in the sequence 8, 16, 32, and so on until responding decreased, whereupon the schedule size was decreased in reversed order to the original steps. Eight percent alcohol was strongly preferred at the nonindependent FR 8 FR 8 baseline. As schedule size increased, intake of the 8% alcohol solution decreased and intake of the alternative liquid increased. Consumption of the alternative liquid generally remained elevated over initial values when schedule size decreased. The data can be analyzed in several ways, including consumption as a function of price (behavioral economics) and log of relative response rates as a function of log of relative deliveries (matching), thereby providing an interface between behavioral economics and matching analyses.

Projected alcohol demand in college students with heavy drinking

Ano: 2025

Abstract Measures of the relative reinforcing value of alcohol (i.e., alcohol demand ) are associated with concurrent and future rates of alcohol use. Given that college‐age young adults may fail to predict escalation of substance use, the present project explores the novel construct of projected future demand by college students who engage in heavy drinking and whether it can predict future alcohol use. During an initial session, participants completed a standard alcohol purchase task, a projected alcohol purchase task (i.e., “three months from now”), and measures of past‐month alcohol consumption and associated risk. During a follow‐up session 3 months later, participants completed another standard alcohol purchase task and measures of consumption and risk. We found that college students ( n = 40) projected increases in demand for 3 months in the future but did not exhibit subsequent changes in demand. In addition, measures of projected future demand were associated with subsequent alcohol use. However, when baseline alcohol use and risk were included as additional predictors, projected demand was not a unique predictor of future alcohol use. The current study signals the potential of novel measures of projected demand, which when contrasted with measures of current demand, may lend predictive utility on subsequent trajectories of alcohol use.