Psychology ETDs


Bob Kosiba

Publication Date



The major purpose of this experiment was to extend the experimental analysis of temporal compounds to differential operant conditioning, and to study a variety of tasks differing in their difficulty due to the presence of various components and the assignment of reinforcement contingencies. After initial bar-press training in a Skinner Box equipped with a response bar, food delivery cup, and the mechanics to present sound and light stimulation, 48 female albino rats were randomly assigned to 6 groups for discrimination training. All groups were counterbalanced for the assignment of reinforcement to the stimulus configurations. Single stimulus presentation consisted of 1/2 sec. of tone (T) or light (L), and compound stimulus presentation consisted of either the sequence of 1/2 sec. T, 1/2 sec. interval, and then 1/2 sec. L, or the sequence of 1/2 sec. L, 1/2 sec. interval, and then 1/2 sec. T. Any response occurring before the termination of the particular stimulus configuration being presented ended the trial immediately, without the delivery of any reinforcement (45 mg Noyes pellets) which may have been programmed. The various groups and the reinforcement contingencies were as follows: Group IA: T+, L-; Group IB: T-, L+; Group IIA: T+, L-, DRL 1 sec.; Group IIB: T-, L+, DRL 1 sec.; Group IIIA: TL+ , L-; Group IIIB: LT+, T-; Group IVA: TL+, LT-; Group IVB: TL-, LT+; Group VA: TL+, LT-, T-; Group VB: TL-, LT+, L-; Group VIA: TL+ , LT-, T-, L-; and Group VIB: TL-, LT+, T-,L-. Response frequency during ITI, and S+ and S- presentations were recorded automatically. In addition, ten stimulus probes for each ele element of the compounds were administered where appropriate, after the animals had reached a stable asymptote. The relative rates of acquisition for each group, starting with the fastest was I = II= III> IV > V = VI, with Groups V and VI not attaining as high an asymptote of performance as the other groups after 2500 trials. The stimulus probe results indicate that the animals in Groups III and IV solve the discrimination on the basis of which stimulus occurs first in the configuration. The overall results imply that an extension of attention theory is necessary to explain the differential conditioning obtained using this paradigm. The most likely candidate appears to be Hull's notions of the stimulus trace and afferent neural interaction.

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First Committee Member (Chair)

Frank Anderson Logan

Second Committee Member

G. Robert Grice

Third Committee Member

Douglas Peter Ferraro



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Psychology Commons