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

Abstract

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.

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.…”

Token reinforcement: Translational research and application

“…Similar demand methods have been applied to token reinforcement contingencies. Tan and Hackenberg (), for example, generated demand functions for specific and generalized reinforcers in a token economy with pigeons. The pigeons could earn specific tokens (exchangeable for either food or water) or generalized tokens (exchangeable for both food and water).…”

“…In subsequent phases of the study, Tan and Hackenberg () included additional assessments of token reinforcer efficacy—PR breakpoint and preference—to assess the correlation between the different measures. Elasticity from the demand analysis was highly correlated with preference in pairwise choices between the different token types.…”

“…Demand analyses can also be applied to concurrently available reinforcers. In the final phase of the Tan and Hackenberg () study, pigeons were given three sets of pairwise choices between the three token types: food versus water, food versus generalized, and water versus generalized. When food tokens were pitted against water tokens, pigeons produced and exchanged approximately 80% of the tokens for food and 20% for water.…”

“…More than a mere synonym, however, substitution—when linked to a demand analysis—puts a sharper quantitative point on the relationship, permitting one to determine not only whether one reinforcer substitutes for another but also the degree to which it does so. In the Tan and Hackenberg () study, generalized tokens substituted to a higher degree for food (nearly full substitutes) than for water (partial substitutes). The type of quantification permitted by an economic analysis is a valuable tool in mapping the continuum of generalizability discussed above, and for reinforcer assessments in applied work.…”