Generalized conditioned reinforcement with pigeons in a token economy

Abstract

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.

Substitution effects in a generalized token economy with pigeons

“…The selective substitution that occurred under price‐change conditions is consistent with prior results (DeFulio et al, ; Tan & Hackenberg, ), and underscores an important function of generalized reinforcers—that of standing in place of other reinforcers. Indeed, such selective substitution, in which generalized reinforcers are earned and exchanged for multiple reinforcers, may be a distinctive function of generalized reinforcers, and key to their reinforcing efficacy.…”

“…The present procedures were not designed to distinguish the reinforcing from the discriminative functions of the embedded correlated stimuli; it is likely that both contributed to the results, especially given these pigeons’ extensive histories with generalized token reinforcement—histories that predated the present study. These pigeons served previously in the DeFulio et al () study, along with two additional subjects not part of the present investigation. In that study, five of six pigeons showed consistent preference for the generalized tokens over equally‐priced specific tokens, including the three pigeons (999, 271, 113) that preferred the generalized tokens in the present study.…”

“…In most previous research on generalized reinforcement, the economy was only partially closed—that is, restricted postsession access for one reinforcer while unlimited access for the other. For example, in conditions in a food‐restricted economy in the DeFulio et al () study, daily access to food occurred within the session, whereas water was available both inside and outside the session. The economy was thus closed with respect to food but open with respect to water.…”

Token reinforcement: Translational research and application

“…These findings are broadly consistent with laboratory research with pigeons in token economies (DeFulio, Yankelevitz, Bullock, & Hackenberg, ). Under various experimental arrangements, pigeons could produce either specific tokens or generalized tokens.…”

Pigeons’ demand and preference for specific and generalized conditioned reinforcers in a token economy

“…The present study was designed to explore in greater depth these types of reinforcer interactions in a generalized token economy. First, unlike the DeFulio et al () study, some conditions in the present study were conducted in a fully closed economy in which daily intake of food and water occurred within the experimental sessions, designed to enhance the generalized functions of the tokens. Second, using known complementary reinforcers (food and water) but including a generalized type with the potential to function as a substitute for these more specific reinforcers, we directly assessed the substitutability function of the generalized tokens.…”