Punishment of an extinguishing shock-avoidance response by time-out from positive reinforcement.

Two experiments were conducted to determine the effects of punishment by time-out from positive reinforcement on the extinction of discriminated shock-avoidance responding. Subjects were trained initially to bar press for food on an intermittent schedule of reinforcement and, concurrently, to avoid shock at the onset of a warning signal. Experiment I compared avoidance extinction performance under no punishment and when avoidance responding resulted in a 30-sec TO from reinforced appetitive responding. In Exp II, the contingent use of TO punishment was compared with its random, or noncontingent use. The results of both experiments showed that in the absence of punishment, avoidance extinction was characterized by short latencies and nearly 100% avoidance responding. Avoidance responding in extinction was little affected by noncontingent TO punishment. When TO was made contingent upon avoidance responding, however, avoidance latencies immediately increased and the frequency of avoidance responses subsequently decreased to zero.