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Date of Award
Master of Arts (M.A.)
The purpose of the present investigation is to add to the growing body of knowledge about the behavioral development of rats. It is an enlargement of a study by Roberts (1966) who investigated the effects of quantitative reward shifts on the behavior of immature rats. Roberts' experiment was in turn founded on earlier experiments by Crespi (1942). These experiments tested the effect of different quantitative reward levels on the behavior of adult rats. These studies of Crespi are fundamental to the understanding of the present investigation and so are discussed below in some detail.
Crespi trained adult rats, one trail a day, to run a runway for different amounts of food reinforcement. He then measured their resulting running speeds. He was able to show that the rats ran at speeds that were proportional to the amount of food reinforcement that they received. As part of the same group of experiments, Crespi pre trained groups of rats to particular quantitative level of food reinforcement. He then shifted them to a different amount and found that a shift to a larger amount of food led to faster running than did original training at the larger amount. A shift to a smaller amount of food led to slower running than did original training at the smaller amount.
Brunner, William Rudolf. (1968). Affective responses to environmental influences in immature rats. University of the Pacific, Thesis. https://scholarlycommons.pacific.edu/uop_etds/1666