A Rat Performs a Memory Exercise (image) Indiana University Share Print E-Mail Caption To test the rats' memory, IU researchers placed the animals inside an "arena" with different odors. The rats were rewarded when they identified the second-to-last item or fourth-to-last odor from a list of unpredictable length. Credit Indiana University Usage Restrictions Credit Indiana University Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.