The Effects of Manipulation of the CS and Variations in the Duration of Response Prevention on Extinction of Avoidance Responses

Abstract

Rats were trained to avoid 0.5 mA shock and, following learning, were divided into two groups ‐ control and experimental. Following acquisition trials, the control animals were left in the shuttle box for 5 min and the experimental animals were removed from the shuttle box and placed in a plastic pail. The CS was presented continuously for 5 min. The rats were then returned to the shuttle box and extinction trials began. The results showed that response prevention was ineffective when it occurred in the presence of the discrete CS. After learning to avoid 0.5 mA shock, animals in the second experiment were divided into the following four groups: controls and three groups which received response prevention for 10 sec, 3 min and 5 min, respectively. The results showed that there was no significant difference between the groups. Clinical implications of the results of both experiments are discussed.