Rats average entire vectors when navigating toward a hidden goal: a test of the vector sum model in rodents

Cheng and colleagues (Cheng, 1988, 1989, 1990; Cheng and Sherry, 1992; Spetch et al., 1992) have shown that birds use vector information from landmarks to return to hidden goal locations. Cheng (1994) subsequently showed that pigeons average the distance and directional components of landmark-to-goal vectors separately, rather than as a single entity (distance-averaging model). Cheng reasoned that other animals might also average the distance and directional components of landmark-to-goal vectors separately, in part, given commonalities in the neural architecture of visual systems. We used procedures developed by Cheng (1994) to examine how rats utilize landmark-to-goal vectors. In contrast to the results with pigeons, we found evidence indicating that rats average whole vectors rather than their separate scalars (vector-averaging). The ways that pigeons and rats use vectors may be related to evolved differences in the visual systems between these two species. This article is part of a Special Issue entitled: CO3 2013.