The effect of criterion level on the acquisition and retention of a 1-way avoidance response in young and old rats.

Young (23-25 days old) and adult (80-84 days old) rats (n = 8, per group) were trained on an active-avoidance task to a criterion of 0, 5, or 15 consecutive correct trials and then tested for retention 30 days later. In original training, both age groups acquired the response in about the same number of trials when the criterion was set at 5/5 but young subjects required significantly more trials than older subjects to learn the response under the 15/15 criterion. In retraining, both age groups performed equally well when original training was to the 15/15 criterion although adults retained significantly better than weanlings when original training was 5/5 correct responses.