| The Morris water maze is widely used to evaluate spatial working memory. The present research employs the Morris water maze to explore working memory for non-spatial visual discrimination. The rat is trained to approach a shape (SD+) associated with a hidden underwater escape platform, and disregard an irrelevant shape (SD-). Two hours after a series of training runs in the water maze, the rats performed the discrimination significantly better than chance. For the first 3- and 4-seconds of a probe trial (no platform present), the rats showed closer proximity to the SD+ than to the SD-. For the first 3 seconds, rats spent significantly more time in the SD+ area. The data suggest young rats can acquire non-spatial visual discriminations in the water maze. This procedure may be used in future research to evaluate impaired visual object memory in aged rats as an alternative model of human age-related memory failure. |
