Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Michael Perone

Committee Co-Chair

Claire St. Peter

Committee Member

Claire St. Peter

Committee Member

Cole Vonder Haar


Although the use of timeout from positive reinforcement is widespread and has been shown to be an effective punisher in clinical settings, the factors responsible for its effectiveness are not fully understood. The present experiment was designed to evaluate one of these factors, the reinforcement rate underway during periods of time-in. Rats’ lever pressing was maintained on variable-interval schedules of food reinforcement in a multiple schedule with two components. In one component, no timeouts were delivered. In the other component, when a variable-ratio schedule was met, lever presses were followed by a 30-s timeout during which a tone sounded, the component light was extinguished, and the food schedule was suspended. Across conditions, the reinforcement rates in both components ranged from 0.5 to 6 pellets per min and the degree of response suppression was evaluated. In the leanest condition, 0.5 pellets per min, the timeouts failed to suppress responding. Generally, as the reinforcement rate was increased, the degree of suppression was enhanced systematically, showing that the punitive function of timeout is directly related to time-in reinforcement rate. The results are discussed in relation to laboratory research on timeout avoidance and shock punishment.