Using Object vs. Place Novelty Tasks to Study the Ontogeny of Spatial Learning

Abstract

Novel object and location recognition tasks harness the rat’s natural tendency to explore novelty (Berlyne, 1950) to study incidental object and spatial learning. The present study examined the ontogenetic profile of these two tasks and retention of spatial learning between postnatal day (PD 17 and 31). Experiment 1 showed that rats at three ages—PD17, 21, and 26— recognize novel objects, but only PD21 and PD26 rats recognize a novel location of a familiar object. These results suggest that novel object recognition develops before PD17, while object location recognition emerges between PD17 and PD21. Experiment 2 studied the ontogenetic profile of object location memory retention in PD21, 26, and 31 rats. PD26 and PD31 rats retained the spatial memory for both the 10 minute and 24-hour delays. PD21rats failed to retain the spatial memory for the 24-hour delay, suggesting an infantile amnesia phenomenon in the development of incidental object location memory (Campbell & Spear, 1972).