Passive avoidance is a test that assesses memory for a negative reinforcer (a mild electric shock) in a certain context. Good memory recall is shown when the animal avoids the aversive location.

Olfactory bulbectomized (OBX) and sham rats were trained before surgery and tested 7 and 14 days after surgery in the passive avoidance test. Sham rats show longer latency compared to the OBX rats, indicating adequate learning and memory. OBX rats, on the other hand, show cognitive deficit as seen in their inability to learn the task.