CONDITIONED INHIBITION OF FEAR RESULTING FROM NEGATIVE CS-US CONTINGENCIES

Reports 2 experiments which indicate that negative contingencies between CSs and shock set up conditioned inhibitors. In Exp. I with 48 male Sprague-Dawley rats, this inhibition was measured by retardation in the subsequent acquisition of a conditioned emotional response (CER) to the CS. Stimuli with greater negative CS-UCS contingencies were more retarded in CER acquisition; various control procedures were employed. In Exp II with 32 Sprague-Dawley rats, inhibition was measured by a summation technique. CSs with a history of greater negative relations to shock were more disruptive of the CER normally elicited by a 2nd CS. Taken together, the experiments support the general hypothesis that CS-UCS contingency is an important factor in fear conditioning. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.