Journal of the experimental analysis of behavior最新文献

The development of schedule-induced drinking depends on different variables affecting the food delivered at the end of the interfood interval. There are mixed results concerning the effects of varying magnitude and/or preference of different reinforcers in the development of schedule-induced drinking, with some studies showing higher levels and other studies showing lower levels of drinking. The purpose of this study was to observe how differences in preference for a flavor of equally nutritious food pellets influence the development and maintenance of schedule-induced drinking. Using the operant demand framework, four flavors of food pellets were compared to form two groups: one in which subjects would receive their most preferred flavor and another in which subjects would receive their least preferred flavor. In general, licking rates were lower and magazine-entering rates were higher when the preferred flavor was delivered regardless of the fixed-time schedule used. It is suggested that the value of the reinforcer has a larger influence on the immediately preceding behaviors, which will determine the distribution of competing responses in the interreinforcement intervals. These results are relevant to developing public policies that manipulate the taste of healthy food to increase its consumption.

Obesity may be more prevalent among populations who are of low socioeconomic status, have limited access to nutrient-dense foods, or both. One such population is justice-involved youth. This series of translational experiments builds on previous research on food reinforcement and behavioral demand by (a) assaying demand for snack foods among justice-involved adolescents and (b) evaluating the effect of a nutrition intervention on justice-involved adolescents' demand for healthier alternatives. In Experiment 1, participants completed preference assessments for high- and low-energy-density snack foods and corresponding commodity purchasing tasks. The results indicated significant differences in demand based on energy density and preference. In Experiment 2, justice-involved adolescents received a nutrition intervention. Following intervention, participants repeated preference assessments and commodity purchasing tasks. The researchers used mixed-effects modeling to evaluate the effect of (a) the intervention, (b) participant age, and (c) the amount of intervention received on pre–post differences in demand for healthier alternatives. Results and implications are discussed along with future directions for improving conditions of confinement for justice-involved adolescents.

Different personal information types are shared at different rates during a social-discounting task. However, it is unclear whether differences in social-discounting rates between different personal information types are related to differences in valuing personal information. To assess the value of personal information more directly, 160 university student participants completed four hypothetical purchase tasks (HPT) for protecting identification, health, security, and financial personal information at 17 ascending price points and a social-discounting task for one of those four different personal information types. The results for social discounting partially replicated those of a previous study where discounting rates for health information were higher than those for financial information. The results for the HPT largely mirrored those for the social-discounting task. The demand for protecting financial information was significantly higher relative to the that for the other three types of personal information for most demand indices such as the highest price participants were willing to pay for the protection of personal information (break point) and the price where consumption for personal information protection became elastic (P_max). However, there were no significant relations between social-discounting rate and HPT demand indices. These results show that value may play a role in the observed differences in social-discounting rate for personal information, but additional factors likely contribute to these differences.

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.

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.

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.

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.

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.

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.