The present study examined pigeons' token accumulation and food reinforcer demand within a token economy using a behavioral economic approach. Six pigeons were exposed to a token reinforcement procedure, in which responses on a token-production key produced tokens. When at least one token was earned, an exchange-production key became simultaneously available, and at this juncture, pigeons chose between earning tokens or producing the exchange period during which accumulated tokens could be exchanged for food reinforcers. Token accumulation was examined as a function of five economically relevant experimental variables: the token-production ratio (labor productivity), exchange-production ratio (transaction costs), token-exchange price, the number of free tokens (nonlabor income), and token-reinforcement magnitude (wage). Results revealed that token accumulation varied systematically with the token-production ratio, the exchange-production ratio, and token-reinforcement magnitude but was less affected by the token-exchange price and the number of free tokens. In addition, consistent with behavioral economic models of demand, overall food consumption decreased consistently under higher response costs regardless of whether the costs were defined in terms of tokens, exchange periods, or food. Collectively, these findings show how token reinforcement systems apply to everyday economic behaviors such as saving, spending, and demand, providing a bridge between reinforcement theory and behavioral economics.

We arranged conditions of social enrichment for a group of six pigeons as part of a larger program of research concerned with an animal model of gambling. When not in their experimental sessions, the pigeons lived together in a free-flying aviary, interacting with each other and with a physical environment that included perches, nesting materials, and nesting boxes. This enabled a range of species-typical social behavior including courtship, mating, and reproductive behavior. To minimize human involvement and the potential stress of daily captures, we devised procedures whereby the pigeons could choose to exit each day by flying one-by-one on cue into a box attached to the porthole door of the aviary from which they were transported to the test apparatus for their daily experimental sessions. By the end of this training, all pigeons were consistently entering the box independently in the presence of their own distinctive cues for transport to the session, and this continued for a maintenance phase during which each pigeon chose to participate in 120 daily sessions. The findings show the power of using reinforcement-based methods to solve practical problems in animal enrichment and welfare, balancing the welfare needs of the animals with the needs of the research.

Token economies are among the oldest and most successful teaching programs in applied behavior analysis. Despite a rich history of basic and applied research on token systems, there remains a research-to-practice gap. Our aim in this paper is to bridge this gap between research and application, by providing evidence-based recommendations and practical guidelines for application of token reinforcement methods. The recommendations in Part 1 are for building a token economy from the ground up, in learners without a history of token reinforcement, whereas those in Part 2 are concerned with existing token economies without regard to how they were established. Although token economies have proven generally effective across a range of settings and populations, they could be even more effective when based on the latest research and theory. Thus, apart from specific recommendations, we hope to show the benefits of an integrated evidence-based approach to the application of token reinforcement principles in educational and clinical settings.

Rats were studied in social reinforcement procedures in which lever presses opened a door separating two adjacent spaces, permitting access to social interaction with a partner rat. The number of lever presses required for social interaction was systematically increased across blocks of sessions according to fixed-ratio schedules, generating demand functions at three different social reinforcement durations: 10 s, 30 s, and 60 s. The social partner rats were cagemates in one phase, and non-cagemates in a second phase. The rate at which social interactions were produced declined with the fixed-ratio price, and was well described by an exponential model that has been successfully employed with a range of social and non-social reinforcers. None of the main parameters of the model varied systematically with social interaction duration or with the social familiarity of the partner rat. On the whole, the results provide further evidence of the reinforcing value of social interaction, and its functional parallels with non-social reinforcers.

Prior research has shown that responding can be maintained under concurrent food and social reinforcement in rats, but little is known about interactions between these reinforcers. In the present study, we approached the problem from a behavioral-economic perspective, using demand-curve methods to analyze demand for, and interactions between, food and social reinforcement. Four rats were given repeated choices between food and 10-s of social access to a partner rat on concurrent schedules, with social access arranged by lifting a door to a restraint, within which the partner rat was held. The fixed-ratio prices of the food and social interaction were varied, separately or together, generating within-subject demand functions. Demand for both food and social interaction decreased with increases in their own price (own-price elasticity), though food reinforcers were more robust (higher levels of consumption at the lowest price) and less sensitive to price (less elastic) than was social interaction. Demand for a constant-price of social interaction increased with increases in the price of food (positive cross-price elasticity), suggesting a substitutable relationship. Demand for a constant-price of food did not change with increases in the price of social access, suggesting no reinforcer interaction. Demand for food alone was less elastic than demand for food in the presence of social reinforcement opportunities, showing that value of food is modified by the presence and availability of social reinforcement. The results provide further evidence of the reinforcing value of social interaction, and how it is modified by the broader economic context in which it occurs, including the price and availability of qualitatively different reinforcers of higher value.

Rats were given repeated choices between social and nonsocial outcomes, and between familiar and unfamiliar social outcomes. Lever presses on either of 2 levers in the middle chamber of a 3-chamber apparatus opened a door adjacent to the lever, permitting 45-s access to social interaction with the rat in the chosen side chamber. In Experiment 1, rats preferred (a) social over nonsocial options, choosing their cagemate rat over an empty chamber, and (b) an unfamiliar over a familiar rat, choosing a non-cagemate over their cagemate. These findings were replicated in Experiment 2 with 2 different non-cagemate rats. Rats preferred both non-cagemate rats to a similar degree when pitted against their cagemate, but were indifferent when the 2 non-cagemates were pitted against each other. Similar preference for social over nonsocial and non-cagemate over cagemate was seen in Experiment 3, with new non-cagemate rats introduced after every third session. Response rates (for both cagemate and non-cagemate rats) were elevated under conditions of nonsocial (isolated) housing compared to conditions of social (paired) housing, demonstrating a social deprivation effect. Together, the experiments contribute to an experimental analysis of social preference within a social reinforcement framework, drawing on methods with proven efficacy in the analysis of reinforcement more generally.

Prior research has found that one rat will release a second rat from a restraint in the presence of food, thereby allowing that second rat access to food. Such behavior, clearly beneficial to the second rat and costly to the first, has been interpreted as altruistic. Because clear demonstrations of altruism in rats are rare, such findings deserve a careful look. The present study aimed to replicate this finding, but with more systematic methods to examine whether, and under what conditions, a rat might share food with its cagemate partner. Rats were given repeated choices between high-valued food (sucrose pellets) and 30-s social access to a familiar rat, with the (a) food size (number of food pellets per response), and (b) food motivation (extra-session access to food) varied across conditions. Rats responded consistently for both food and social interaction, but at different levels and with different sensitivity to the food-access manipulations. Food production and consumption was high when food motivation was also high (food restriction) but substantially lower when food motivation was low (unlimited food access). Social release occurred at moderate levels, unaffected by the food-based manipulations. When food was abundant and food motivation low, the rats chose food and social options about equally often, but sharing (food left unconsumed prior to social release) occurred at low levels across sessions and conditions. Even under conditions of low food motivation, sharing occurred on only 1% of the sharing opportunities. The results are therefore inconsistent with claims in the literature that rats are altruistically motivated to share food with other rats.

Rats were studied in social-release procedures, in which lever presses by one rat released a second rat from a tube restraint for a period of social interaction. Both the fixed-ratio price and the duration of social contact were varied systematically on a within-subject basis, generating a total of 27 demand functions across six subjects. Overall, the data were well accounted for by the essential value model (96% VAF), supporting a social reinforcement view, according to which social-release behavior is maintained by social contact with another rat. Response rates and parameter fitswere comparable in 25-min and 120-min sessions, showing little evidence of satiation.Overall, the findings suggest that socially-reinforced behavior shares functionalproperties with other reinforcers, and illustrate a promising set of methods for quantifying social reinforcement value.

The present paper provides an integrative review of research on token reinforcement systems, organized in relation to basic behavioral functions and economic variables. This type of functional taxonomy provides a useful way to organize the literature, bringing order to a wide range of findings across species and settings, and revealing gaps in the research and areas especially ripe for analysis and application. Unlike standard translational research, based on a unidirectional model in which the analysis moves from laboratory to the applied realm, work in the area of token systems is best served by a bidirectional interplay between laboratory and applied research, where applied questions inspire research on basic mechanisms. When based on and contributing to an analysis, applied research on token economies can be on the leading edge of theoretical advances, helping set the scientific research agenda.

The present research measured social reinforcement in rats, using a social-release procedure in which lever presses permitted 10-s access to a familiar social partner. The work requirements for reinforcement increased systematically according to progressive-ratio (PR) schedules. Social and food reinforcement value were compared across blocks of sessions (Experiment 1) and concurrently within the same sessions (Experiment 2). To assess motivational effects, response and reinforcer rates for both reinforcer types were studied under food restriction, social restriction, and combined food and social restriction. Responding was maintained by both reinforcers, albeit at substantially higher levels for food than for social access. Responding for social access decreased to low levels under extinction conditions, demonstrating functional control by the social-reinforcement contingency. Sensitivity to social restriction was seen in some conditions in Experiment 2, in which social reinforcers were earned earlier in the session (at lower food prices) under social restriction than under the other deprivation conditions. Altogether, results are consistent with a social reinforcement conceptualization, and demonstrate an important role for social contact in social release behavior. The study demonstrates a promising set of methods for analyzing and quantifying social reinforcement.

Eating disorders are associated with impaired decision-making and dysfunctional reward-related neurochemistry. The present study examined the potential contributions of dopamine and opioid signaling to these processes using two different decision-making tasks. In one task, Long Evans Rats chose between working for a preferred food (high-carbohydrate banana-flavored sucrose pellets) by lever pressing on a progressive-ratio schedule of reinforcement vs. obtaining less preferred laboratory chow that was concurrently available. In a second (effort-free) task, rats chose between the same two reinforcers when they were both available freely. Rats were trained in these tasks before receiving haloperidol (0.00, 0.05, 0.10 mg/kg, intraperitoneally (i.p.)) or naloxone (0.0, 1.5, 3.0 mg/kg, i.p.). In the first task, haloperidol decreased breakpoint, lever presses, number of reinforcers earned, and increased chow intake, whereas naloxone decreased breakpoint and number of reinforcers earned but had no effect on chow consumption. In the effort-free task, haloperidol reduced intakes of both foods without affecting preference, whereas naloxone selectively reduced the consumption of banana pellets. The present findings support converging evidence suggesting that DA signaling affects processes more closely related to appetitive motivation, leaving other components of motivation unchanged. By contrast, opioid signaling appears to mediate aspects of hedonic feeding by selectively altering intakes of highly palatable foods. For preferred foods, both appetitive and consummatory aspects of food intake were altered by opioid receptor antagonism. Our findings argue against a general suppression of appetite by either compound, as appetite manipulations have been shown to unselectively alter intakes of both types of food regardless of the task employed.

Pigeons made repeated choices between earning and exchanging reinforcer-specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer-general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed-ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token-production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token-economic methods for assessing demand for and substitution among multiple commodities in a laboratory context.

Three pairs of rats were trained to synchronize their lever pressing according to a mutual reinforcement contingency, in which alternating lever presses that fell within a 500-ms window were reinforced with food. In Experiment 1, rats worked in adjacent chambers separated by a transparent barrier, and the effects of the mutual reinforcement contingency were compared with those under yoked-control conditions that provided the same rate of food reinforcement but without the temporal coordination response requirement. In Experiment 2, coordinated behavior was compared with and without a barrier, and across different barrier types: transparent, opaque, wire mesh. In Experiment 3, the effects of social familiarity were assessed by switching partners, enabling a comparison of coordinated behavior with familiar and unfamiliar partners. The overall pattern of results shows that the coordinated behavior of 2 rats was (a) maintained by mutual reinforcement contingencies, (b) unrelated to the type or presence of a barrier separating the rats, and (c) sufficiently flexible to adjust to the presence and behavior of an unfamiliar partner. Taken as a whole, the study illustrates a promising approach to conceptualizing and analyzing behavioral mechanisms of mutual behavior, an important component of an integrated study of social behavior.

A continuidade no comportamento entre espécies tem sido amplamente assumida na análise do comportamento, embora pesquisas recentes pareçam desafiar uma versão forte do pressuposto da continuidade. Este artigo apresenta uma revisão de fontes potenciais para a descontinuidade humano-não humano em escolha e auto-controle. Ênfase especial é colocada nas diferenças nos procedimentos empregados para estudar humanos e outros animais, que dificultam comparações entre espécies. Modificações nos procedimentos empregados com não-humanos (por meio do uso de sistemas de reforço do tipo fichas) e com humanos (por meio do emprego de sistemas de reforço do tipo consumatório) mostram maior acordo nos padrões de escolha de humanos e outros animais. Isto sugere que pelo menos algumas das diferenças relatadas sobre escolhas em procedimentos de autocontrole em humanos e outros animais refletem diferenças de procedimento, mais do que diferenças mais fundamentais em processos comportamentais. Ao estreitar as lacunas metodológicas que separam procedimentos empregados com humanos e não humanos, esta pesquisa aponta estratégias mais efetivas para avaliar a continuidade no comportamento entre espécies.Palavras-chave: escolha, autocontrole, reforçamento por fichas, reforço consumatório, continuidade entre espécies.

Pigeons' demand and preference for specific and generalized tokens was examined in a token economy. Pigeons could produce and exchange different colored tokens for food, for water, or for food or water. Token production was measured across three phases, which examined: (1) across-session price increases (typical demand curve method); (2) within-session price increases (progressive-ratio, PR, schedule); and (3) concurrent pairwise choices between the token types. Exponential demand curves were fitted to the response data and accounted for over 90% total variance. Demand curve parameter values, Pmax , Omax and α showed that demand was ordered in the following way: food tokens, generalized tokens, water tokens, both in Phase 1 and in Phase 3. This suggests that the preferences were predictable on the basis of elasticity and response output from the demand analysis. Pmax and Omax values failed to consistently predict breakpoints and peak response rates in the PR schedules in Phase 2, however, suggesting limits on a unitary conception of reinforcer efficacy. The patterns of generalized token production and exchange in Phase 3 suggest that the generalized tokens served as substitutes for the specific food and water tokens. Taken together, the present findings demonstrate the utility of behavioral economic concepts in the analysis of generalized reinforcement.

Three experiments were conducted with pigeons to identify the stimulus functions of tokens in second-order token-reinforcement schedules. All experiments employed two-component multiple schedules with a token-reinforcement schedule in one component and a schedule with equivalent response requirements and/or reinforcer density in the other. In Experiment 1, response rates were lower under a token-reinforcement schedule than under a tandem schedule with the same response requirements, suggesting a discriminative role for the tokens. In Experiment 2, response rates varied systematically with signaling functions of the tokens in a series of conditions designed to explore other aspects of the temporal-correlative relations between tokens and food. In Experiment 3, response rates were reduced but not eliminated by presenting tokens independent of responding, yoked to their temporal occurrence in a preceding token component, suggesting both a reinforcing function and eliciting/evocative functions based on stimulus-food relations. Only when tokens were removed entirely was responding eliminated. On the whole, the results suggest that tokens, as stimuli temporally correlated with food, may serve multiple stimulus functions in token-reinforcement procedures--reinforcing, discriminative, or eliciting--depending on the precise arrangement of the contingencies in which they are embedded.

Six pigeons were studied in a token economy in which tokens could be produced and exchanged for food on one side of an experimental chamber and for water on the opposite side of the chamber. Responses on one key produced tokens according to a token-production fixed ratio (FR) schedule. Responses on a second key produced an exchange period during which tokens were exchanged for water or food. In Experiment 1a, food tokens could be earned and exchanged under restricted food budgets, and water tokens could be earned and exchanged under water restricted budgets. In Experiment 1b, a third (generalized) token type could be earned and exchanged for either food or water under water restricted budgets. Across Experiments 1a and 1b, the number of tokens accumulated prior to exchange increased as the exchange-production schedule was increased. In Experiment 1b, pigeons produced more generalized than specific tokens, suggesting enhanced reinforcing efficacy of generalized tokens. In Experiment 2, the FR token-production price was manipulated under water restriction and then under food restriction. Production of each token type generally declined as a function of its own price and increased as a function of the price of the alternate type, demonstrating own-price and cross-price elasticity. Production of food and water tokens often changed together, indicating complementarity. Production of specific and generalized tokens changed in opposite directions, indicating substitutability. This is the first demonstration of sustained generalized functions of tokens in nonhumans, and illustrates a promising method for exploring economic contingencies in a controlled environment.