Alleviation of forgetting in preweanling rats.

Three experiments tested the learning and retention of neonatal rats (7, 9, and 12 days of age) with a nondirectional active avoidance task, using a vibrotactile conditioned stimulus. The hypothesis was that the substantial deficit of these animals in 24-hr retention is due, at least in part, to a deficiency in memory retrieval. In Experiment I, a reactivation treatment was found to alleviate the forgetting over the 24-hr period for 12-day olds although having somewhat lesser effect for animals 9 days of age. The reactivation treatment seemed ineffective for rats 7 days of age. Experiments II and III confirmed the reliability of the reactivation effects with 9- and 12-day olds, while adding further control conditions and providing new information concerning the ontogenesis of latent inhibition.