Abstract
Eight pigeons were exposed to independent concurrent schedules. Concurrent variable-interval 60-second variable-interval 60-second schedules were presented to one group of four subjects. Following baseline training, a limited hold was added to one of the schedules and the duration of the hold was decreased in successive conditions. Concurrent variable-interval 120-second variable-interval 40-second schedules were presented to another group of four subjects. These subjects were first exposed to decreasing durations of a limited hold in the variable-interval 40-second component. After replication of the baseline, a limited hold in the variable-interval 120-second component was decreased in duration. The initial durations of the holds were determined from the subjects' responding in the baseline conditions. A duration was chosen such that approximately 25% of the scheduled reinforcers would be canceled if responding remained unchanged.
Approximate matching of time proportions and reinforcement proportions was observed when the limited hold was added to the variable-interval 60-second schedule and when the limited hold was added to the variable-interval 40-second schedule. Time proportions were less extreme than reinforcement proportions when the limited hold operated in a variable-interval 120-second schedule. Overall reinforcement rates tended to decrease with continued training in concurrent schedules with a limited hold. Absolute deviations from time matching also decreased. The results provide evidence against the principle of reinforcement maximization, and support Herrnstein and Vaughan's (1980) melioration hypothesis.
Keywords: melioration, maximization, concurrent schedules, limited hold, key peck, pigeons
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Selected References
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- Baum W. M. Matching, undermatching, and overmatching in studies of choice. J Exp Anal Behav. 1979 Sep;32(2):269–281. doi: 10.1901/jeab.1979.32-269. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FLESHLER M., HOFFMAN H. S. A progression for generating variable-interval schedules. J Exp Anal Behav. 1962 Oct;5:529–530. doi: 10.1901/jeab.1962.5-529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Herrnstein R. J., Heyman G. M. Is matching compatible with reinforcement maximization on concurrent variable interval variable ratio? J Exp Anal Behav. 1979 Mar;31(2):209–223. doi: 10.1901/jeab.1979.31-209. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mazur J. E. Optimization theory fails to predict performance of pigeons in a two-response situation. Science. 1981 Nov 13;214(4522):823–825. doi: 10.1126/science.7292017. [DOI] [PubMed] [Google Scholar]
- Vaughan W. Melioration, matching, and maximization. J Exp Anal Behav. 1981 Sep;36(2):141–149. doi: 10.1901/jeab.1981.36-141. [DOI] [PMC free article] [PubMed] [Google Scholar]