Stepping into a map: initial heading direction influences spatial memory flexibility.

Learning a novel environment involves integrating first-person perceptual and motoric experiences with developing knowledge about the overall structure of the surroundings. The present experiments provide insights into the parallel development of these egocentric and allocentric memories by intentionally conflicting body- and world-centered frames of reference during learning, and measuring outcomes via online and offline measures. Results of two experiments demonstrate faster learning and increased memory flexibility following route perspective reading (Experiment 1) and virtual navigation (Experiment 2) when participants begin exploring the environment on a northward (vs. any other direction) allocentric heading. We suggest that learning advantages due to aligning body-centered (left/right/forward/back) with world-centered (NSEW) reference frames are indicative of three features of spatial memory development and representation. First, memories for egocentric and allocentric information develop in parallel during novel environment learning. Second, cognitive maps have a preferred orientation relative to world-centered coordinates. Finally, this preferred orientation corresponds to traditional orientation of physical maps (i.e., north is upward), suggesting strong associations between daily perceptual and motor experiences and the manner in which we preferentially represent spatial knowledge.