Degree Name

Master of Arts (MA)

Semester of Degree Completion

1980

Thesis Director

John J. Rearden

Abstract

Twelve adult male rats were given free access to a two bottle free-selection of tap water or a 10% ethanol/tap water solution in the home cage for a period of 140 consecutive days with the alcohol consumption data in the form of mg absolute ETOH/g subject weight collected daily. This study incorporated three stages. Phase I was a 40 day period of alcohol acclimation with alcohol consumption during the second 20 days constituting the baseline consumption rate. Mean baseline alcohol consumption was used to block subjects into three groups. The second phase of the study consisted of an 80 day period during which subjects were exposed to one of three operant schedules 20 min. daily. The two Sidman avoidance schedules had a response-shock interval of 20 sec. and a shock-shock interval of 5 sec. One of the Sidman schedules included a warning signal which preceded shock by 5 sec. Subjects in the third group were yoked to uncued Sidman subjects. Yoked subjects received shock whenever Sidman subjects failed to make an avoidance response. The third phase was a 20 day post operant period in which the subjects remained in the home cages.

During the operant phase of the study the cued Sidman avoidance group was found to receive significantly fewer shocks than the other two groups. A mixed analysis of variance performed on the dependent variable of mean daily alcohol consumption with between subjects variable of group membership and within subjects variable of phase, failed to yield significant differences in alcohol consumption between groups or phases or a significant group-phase interaction effect.

A posteriori multiple regression analysis yielded significant group differences during the post operant phase with the cued Sidman group consuming the greatest quantities followed by the yoked and Sidman groups respectively. Multiple regression analysis of the operant phase yielded a significant relationship between alcohol consumption and days within the phase. When group membership as a variable was forced into the regression equation first, group differences were found to be significant with mean alcohol consumption in the same order as during the post operant phase.

Upon a posteriori examination of the operant phase by inspection of graphic data and stepwise multiple regression analysis, all groups exhibited an initial peak in alcohol consumption between the first and second week followed by a general decline in consumption. Significant linear and cubic temporal patterns of alcohol consumption were demonstrated for the Sidman group, significant linear and quadradic temporal patterns were demonstrated for the cued Sidman group, but no significant temporal patterns were demonstrated for the yoked group. During the period of peak consumption in the operant phase the order of group consumption rates was the Sidman group followed by the cued Sidman and yoked groups respectively.

Results were discussed in terms of contingent as opposed to non-contingent shock, and the possible role of the warning signal as a psychological stressor affecting temporal alcohol consumption.

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