Acquisition and retention of active avoidance behavior in previsual rats.

The ability of previsual rats to acquire and retain an active avoidance response at intervals ranging from 0 min to 48 hr was examined in five experiments. Experiments 1 and 2 demonstrated that improvement in avoidance responding over trials was a training effect. Experiments 3 and 4 demonstrated that there was no evidence of retention of the avoidance response over retention intervals ranging from 15 min to 48 hr. Testing at intervals of 0-30 min in Experiment 5 indicated that 10-day-old rats could retain the response over intervals ranging from 0-15 min, but not over a 30-min interval. However, even at the very short intervals (5-15 min), there was evidence of a retention deficit. In general, the results suggest that previsual rats have sufficient memory capabilities to acquire an active avoidance response and to retain it over a 15-min interval. However, without intervention, e.g., reactivation, a retention deficit appears almost immediately, and retention loss seems complete within 30 min. This procedure and phenomenon may prove useful in allowing an immediate assessment of variables believed to alleviate retention loss and in eliminating the influence of many extraneous variables that could alter the retention performance of developing animals.