DEVALUATION OF PAVLOVIAN CONDITIONING IN THE 10-DAY-OLD RAT

This experiment established that for the infant rat, 10 days postpartum, a preference conditioned to an olfactory stimulus (conditioned stimulus) could be substantially decreased by subsequently lowering the value of the unconditioned stimulus (heat). This devaluation effect disappeared when a sufficiently long interval elapsed between the devaluation treatment and the test, despite maintained retention of the original conditioned preference over this same interval. This suggests that devaluation in infant rats does not permanently change the animal's original representation of the unconditioned stimulus, but instead may replace it temporarily with a conflicting representation.