Abstract
Five rats responded under concurrent fixed-interval variable-ratio schedules of food reinforcement. Fixed-interval values ranged from 50-seconds to 300-seconds and variable-ratio values ranged from 30 to 360; a five-second changeover delay was in effect throughout the experiment. The relations between reinforcement ratios obtained from the two schedules and the ratios of responses and time spent on the schedules were described by Baum's (1974) generalized matching equation. All subjects undermatched both response and time ratios to reinforcement ratios, and all subjects displayed systematic bias in favor of the variable-ratio schedules. Response ratios undermatched reinforcement ratios less than did time ratios, but response ratios produced greater bias than did time ratios for every subject and for the group as a whole. Local rates of responding were generally higher on the variable-ratio than on the fixed-interval schedules. When responding was maintained by both schedules, a period of no responding on either schedule immediately after fixed-interval reinforcement typically was followed by high-rate responding on the variable-ratio schedule. At short fixed-interval values, when a changeover to the fixed-interval schedule was made, responding usually continued until fixed-interval reinforcement was obtained; at longer values, a changeover back to the variable-ratio schedule usually occurred when fixed-interval reinforcement was not forthcoming within a few seconds, and responding then alternated between the two schedules every few seconds until fixed-interval reinforcement finally was obtained.
Keywords: concurrent schedules, fixed-interval schedules, variable-ratio schedules, matching relation, undermatching, bias, lever press, rats
Full text
PDF











Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bacotti A. V. Matching under concurrent fixed-ratio variable-interval schedules of food presentation. J Exp Anal Behav. 1977 Jan;27(1):171–182. doi: 10.1901/jeab.1977.27-171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Baum W. M. On two types of deviation from the matching law: bias and undermatching. J Exp Anal Behav. 1974 Jul;22(1):231–242. doi: 10.1901/jeab.1974.22-231. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Catania A. C., Reynolds G. S. A quantitative analysis of the responding maintained by interval schedules of reinforcement. J Exp Anal Behav. 1968 May;11(3 Suppl):327–383. doi: 10.1901/jeab.1968.11-s327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davison M. C., Hunter I. W. Performance on variable-interval schedules arranged singly and concurrently. J Exp Anal Behav. 1976 May;25(3):335–345. doi: 10.1901/jeab.1976.25-335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HERRNSTEIN R. J. Relative and absolute strength of response as a function of frequency of reinforcement. J Exp Anal Behav. 1961 Jul;4:267–272. doi: 10.1901/jeab.1961.4-267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Herrnstein R. J. On the law of effect. J Exp Anal Behav. 1970 Mar;13(2):243–266. doi: 10.1901/jeab.1970.13-243. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hunter I. W., Davison M. C. Response rate and changeover performance on concurrent variable-interval schedules. J Exp Anal Behav. 1978 May;29(3):535–556. doi: 10.1901/jeab.1978.29-535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Labounty C. E., Reynolds G. S. An analysis of response and time matching to reinforcement in concurrent ratio-interval schedules. J Exp Anal Behav. 1973 Jan;19(1):155–166. doi: 10.1901/jeab.1973.19-155. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lobb B., Davison M. C. Performance in concurrent interval schedules: a systematic replication. J Exp Anal Behav. 1975 Sep;24(2):191–197. doi: 10.1901/jeab.1975.24-191. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Myers D. L., Myers L. E. Undermatching: a reappraisal of performance on concurrent variable-interval schedules of reinforcement. J Exp Anal Behav. 1977 Jan;27(1):203–214. doi: 10.1901/jeab.1977.27-203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nevin J. A. Rates and patterns of responding with concurrent fixed-interval and variable-interval reinforcement. J Exp Anal Behav. 1971 Sep;16(2):241–247. doi: 10.1901/jeab.1971.16-241. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider B. A. A two-state analysis of fixed-interval responding in the pigeon. J Exp Anal Behav. 1969 Sep;12(5):677–687. doi: 10.1901/jeab.1969.12-677. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trevett A. J., Davison M. C., Williams R. J. Performance in concurrent interval schedules. J Exp Anal Behav. 1972 May;17(3):369–374. doi: 10.1901/jeab.1972.17-369. [DOI] [PMC free article] [PubMed] [Google Scholar]
- White A. J., Davison M. C. Performance in concurrent fixed-interval schedules. J Exp Anal Behav. 1973 Jan;19(1):147–153. doi: 10.1901/jeab.1973.19-147. [DOI] [PMC free article] [PubMed] [Google Scholar]