Date of Award


Document Type


Degree Name

Master of Science (MS)




The purpose of this experiment was to determine if simple auditory and visual sensory stimuli were effective reinforcers with mentally retarded children and, if so whether one stimulus was superior to the other. In order to make this determination, a group of eighteen female patients between the ages of seventeen and twenty-seven, having IQ's ranging between 37 and 98, and classified as functioning in adaptive behavior level-III, were assigned by random sampling techniques to three equal groups to participate in a multiple-choice learning situation. The groups of subjects were exposed either to one of the two sensory stimuli (light flash or buzzer) after each correct response or, in the case of the control group, the subjects received only knowledge of results as a possible reinforcer. The following null hypothesis was formulated prior to the experiment. There will be no significant difference between the number of errors committed during the learning task by the groups receiving response-contingent sensory stimuli and the number of errors committed by the control group. The Friedman Two Way Analysis of Variance and the Mann-Whitney U Test were used to determine if there was a significant difference in amount of learning between any of the three groups as measured by number of errors committed per group over all trials. The group receiving response-contingent auditory stimuli was found to be significantly superior in amount of learning only to the group receiving response-contingent visual stimuli; although a trend was seen toward a difference favoring the auditory group over the control group and the control group over the visual group. It was therefore concluded that the present study was unable to demonstrate that response-contingent sensory stimuli provided more reinforcement effect than did mere knowledge of results provided in the control condition; therefore, the data did not justify rejecting the null hypothesis at the .05 level of confidence. it was suggested that the findings of this study be considered indeterminate rather than negative because a number of possibly confounding variables may have obscured any real differences between the groups.


vii, 61 leaves : ill. ; 28 cm. Bibliography: leaves [41]-43.

Included in

Psychology Commons


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