Updating in models of spatial memory

This chapter discusses a new model of spatial memory and updating. The model includes an egocentric subsystem that computes and represents transient self-to-object spatial relations and an environmental subsystem that forms enduring representations of environments using intrinsic reference systems. Updating occurs in both subsystems, but only the egocentric subsystem readily provides object locations relative to any adopted orientation. In the absence of visual support, updating in the egocentric subsystem is limited, and object locations may have to be retrieved from the orientation dependent environmental subsystem. The model is evaluated in light of the results of numerous studies from the areas of spatial memory and spatial updating and contrasted with two alternative models. Furthermore, results are presented that suggest that interobject spatial relations are preferentially represented when they are aligned with intrinsic reference directions in the environmental subsystem.