On how passive is inhibitory avoidance.

Rats were trained in a step-down inhibitory avoidance task using a 25 X 25-cm platform and either a 0.3- or a 0.8-mA training footshock. Immediately after training retrieval was good in all animals; but at 24 h there was a decline in the group trained with 0.3-mA footshock. This decline was not observed in animals submitted to an immediate retrieval test and then tested again at 24 h. Thus, the immediate retrieval test apparently served the purpose of a rehearsal. A considerable degree of activity (rearing, ambulation, sticking the head out of the platform) was observed in test sessions. Activity scores were lower in the animals trained with the 0.8-mA footshock. The amount of activity, however, was unrelated to retrieval performance (i.e., to test session step-down latency).