Biased representations of the spatial structure of navigable environments.

Recent studies (e.g., Shelton & McNamara in Cognitive Psychology, 43(4), 274-310, 2001; Valiquette, McNamara, & Smith in Memory and Cognition, 31(3), 479-489, 2003) have demonstrated that judgments of relative direction (JRD) access a single enduring orientation-dependent allocentric representation of the layout of objects in an environment, regardless of whether the space is viewed from one or multiple vantage points. Two experiments tested the limits of this phenomenon. In both experiments participants learned the locations of objects in a large room from two views: one view was aligned with salient environmental frames of reference (edges of the mat on which objects were placed and walls of the enclosing room) and expected to be preserved in long-term memory; the other view was misaligned and not expected to be preserved in long-term memory. The first experiment demonstrated that performing JRD between studying the misaligned view and studying the aligned view did not result in the misaligned view being maintained in long-term memory. The second experiment demonstrated that after studying the layout extensively from the misaligned view, 30 s of exposure to the aligned view (with no instructions to learn the layout from that view) resulted in the aligned but not the misaligned view being preserved in long-term memory. These findings indicate that the human spatial memory and navigation system is strongly biased to represent the spatial structure of navigable environments with reference directions or axes that are aligned with salient environmental frames of reference.