Psychology ETDs

Publication Date

3-13-1974

Abstract

Pigeons were trained to keypeck for food delivered according to a response-dependent random-interval schedule. Then, in each of three experiments, a control group and an experimental group received multiple schedule successive discrimination training followed by generalization testing in extinction. During discrimination training two component schedules, each associated with a distinctive stimulus projected on the response key, alternated within each session. The component schedules were random-interval reinforcement and extinction for control groups, while one component schedule for experimental groups was random-time food delivery. In the random-time component response-independent food delivery occurred at the same irregular time intervals as in the random-interval schedule.

Interdimensional discrimination training was given in Experiment I. Green alone indicated random-interval for all birds, while a vertical line superimposed on the green surround indicated either extinction (control) or random-time (experimental). Incremental gradients of inhibitory dimensional control were obtained from both groups when line orientation was varied during generalization tests. In Experiment II, a vertical line on green indicated random-interval for all birds, while an oblique line indicated either extinction (control) or random-time (experimental).

Both intradimensional training procedures generally produced peak or distribution shifts in test gradients, Experiment III compared multiple random-interval extinction with multiple random-time extinction discrimination training, where green alone indicated extinction for both groups. Whether vertical line on green had been associated with a response-dependent random-interval or response-independent random-time schedule, equally steep decremental gradients were obtained.

The relative contributions of stimulus-and response-reinforcer contingencies to stimulus control were considered. A stimulus reinforcer contingency was not necessary for the inhibitory gradient or peak shift (Experiments I and II), but was sufficient to steepen the excitatory gradient (Experiment III).

Degree Name

Psychology

Level of Degree

Doctoral

Department Name

Psychology

First Committee Member (Chair)

Douglas Peter Ferraro

Second Committee Member

John Paul Gluck Jr.

Third Committee Member

G. Robert Grice

Fourth Committee Member

Henry Carleton Ellis

Fifth Committee Member

Frank Anderson Logan

Language

English

Document Type

Dissertation

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