Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Dr. Dale M Brethower

Second Advisor

Dr. Norman Peterson

Third Advisor

Dr. Jack Michael

Fourth Advisor

Dr. Howard Poole


Under certain circumstances, rewarding individuals for performing a task that they enjoy may decrease their subsequent interest in that activity when rewards are no longer available. Decreased task interest is not, however, an inevitable outcome of reward and the subsequent termination of reward. This study investigated one variable that may influence whether task interest will increase or decrease following reward termination: the degree to which the reward is reinforcing. The study also examined how long post-reward performance changes persisted when they occurred.

A multiple-trial, within-subject comparison design was employed in which three reward phases were alternated with post-reward phases. Two of seven subjects completed all phases of the study. These subjects responded in a consistent manner to both the termination of reward and to the termination of reinforcement, although one subject exhibited temporary performance decrements while the other subject did not exhibit performance decrements. These results suggest that an individual's reinforcement history may be an important determinant of post-reward and post-reinforcement task performance.

Post-reward decrements may be a form of counter-control evoked by social control techniques. The performance decrements may have been reinforced in the individual's past by withdrawal of the control techniques or by signs of irritation or anger on the part of the controller.

When post-reward decrements occurred, they were very transient. Neither reward or reinforcement termination resulted in permanent decrements in task performance. These results are consistent with results of other studies that have continued to measure performance for several sessions following reward and reinforcement termination.

All of the subjects displayed considerable day-to-day variability in task performance during baseline as well as during subsequent phases. Such variability suggests that task interest was not a strong controlling variable compared to uncontrolled variables such as subject interactions with the experimenter and other subjects.

Access Setting

Dissertation-Open Access