Date of Award


Degree Type


Degree Name

Master of Arts in Psychology



First Advisor

Nelson F. Smith


Forty male rats acquired a lever press response over eight sessions on a fixed interval (FI) schedule of reinforcement. After this acquisition phase subjects were randomly assigned to one of four treatment groups involving response elimination. Three of the groups received varying response-reinforcement intervals of 2, 6 and 18 seconds within a differential reinforcement of other behavior (DRO) paradigm. A reinforcement-reinforcement interval of 10 seconds was used for these animals. A control group receiving a standard extinction (EXT) contingency was also run for this 10 session treatment phase. One 15 minute reaquisition session followed the treatment sessions during which all animals were retrained on a FI 10 s schedule. During the treatment phase significant differences for the four groups were found after the first session. The DRO 2 group responded the most throughout the rest of this phase, followed by the EXT group, the DRO 6 group and finally the DRO 18 group. Significant results from the reacquisition phase were found only between minute two and five. At these times the DRO 2 group did not differ from the EXT group, but these two both were faster to reacquire the original response than both the DRO 6 and the DRO 18 group which had the slowest reacquisition. The results indicated that the longer the response-reinforcement interval the more effective the response elimination during treatment. Also, as a measure of permanence, the longer the response-reinforcement interval the more permanent the response suppression.



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