Long-term effects of suppressing the preratio pause.

The preratio pause is a characteristic feature of performances under fixed-ratio schedules of reinforcement, even though the pause is not required by the schedule and it reduces the reinforcement rate. To investigate the reduction of pausing, five rats trained on fixed-ratio schedules were exposed to timeout punishment of pauses that exceeded a specified duration. After a series of 30 punishment sessions, most of the longest pauses were eliminated. For some subjects punishment was withdrawn abruptly, whereas for others a fading procedure was employed. Postpunishment observations then were continued for an additional 60 sessions. The reduced pausing was accompanied by reductions in the positive skew of the baseline distribution of pause durations, and by substantial increases in reinforcement rates. However, the results did not indicate differences as a function of the method of withdrawing the punishment contingency. Although postpunishment performances indicated some degree of recovery in the number of long pauses, performances had stabilized below prepunishment levels when the experiment ended. The results suggest the possibility that reduced pause durations can be self-maintained by the resulting increase in reinforcement rates.