AGE-DEPENDENT EFFECTS OF PRECONDITIONING AVERSIVE EXPERIENCES ON THE RETENTION OF CONDITIONED FEAR IN WEANLING RATS

Two experiments investigated the effect of prior noncontingent shock experience upon the retention of fear in young rats. Rats given Pavlovian fear conditioning at 20 days of age and tested 2 or 4 weeks later showed less forgetting if they had received preconditioning shocks in infancy. The magnitude of this protection effect was inversely related to the age at which the prior experience had occurred. As preshock treatments did not appear to affect acquisition, the improved retention does not seem to be based upon changes in original learning. Early experience may enhance memory processes by increasing cue utilization. © 1979 Academic Press, Inc.