For example, Good et al. (2007)tested rats with hippocampal lesions on the standard NOR task, in which familiar objects are replaced with novel ones at test, along with a version in which the relative location of objects was manipulated during the test. In this version, rats were familiarized with four objects and at test the location of two of the objects was switched. In the standard task, both hippocampal and control rats showed novelty preferences, exploring the novel objects more than the familiar ones. When tested on the spatial relational version, control rats spent a greater percentage of time than would be predicted by chance exploring the familiar objects that had switched locations; however, hippocampal rats did not explore the objects that had been switched for any longer than the objects that remained in the same configuration. These results suggest that thehippocampus is not critical for object recognition per se but is involved in integrating identity and location information into a relational network. Hippocampal animals are unable to encode the relative position of objects or recognize that the spatial relations in an array of objects have been changed (Good et al., 2007).