Contingency in fear conditioning: A reexamination

Abstract

The effects on classical fear conditioning of the rate of presentation of the unconditioned stimulus (US) and the contingency between the conditioned stimulus (CS) and the US were examined using the conditioned emotional response procedure with rats. Increases in US rate reduced suppression by the same amount whether the added USs were signaled by CS, thereby maintaining the CS-US contingency, or unsignaled, thereby weakening the CS-US contingency. Failure to control for the rate of US presentation in previous studies of the effect of CS-US contingency on fear conditioning has led to the unsubstantiated conclusion that CS-US contingency is fundamental to classical conditioning. © 1981, The Psychonomic Society, Inc.. All rights reserved.