Abstract
To successfully navigate to a target, one must represent its location at multiple spatial scales. For example, to find a favorite coffee mug requires remembering that it is in one's office and in the back corner. An intuitive hypothesis is that we accomplish this task by accessing the same representation at progressively finer levels of granularity—first remembering the general location and then "zooming in." Here we provide evidence for a different view, in which independent representations are used for different spatial scales. Subjects in 7 experiments learned the location of objects positioned within four visually-distinct but geometrically-identical buildings that were situated within a broader virtual park. They were then tested on their knowledge of object location by asking them to navigate to the remembered location of each object. We examined errors during the test phase for confusions among geometrically analogous locations in different buildings—that is, navigating to the right location in the wrong building. We observed that subjects frequently made these confusions, which are analogous to remembering a passage's location on the page of a book but not remembering the page that the passage is on. This suggests that subjects were recalling the object's local location without recalling its global location. Further manipulations indicated that geometric confusions were observed even between buildings that were not metrically identical as long as geometrical equivalence could be defined. However, removing the walls so that the larger environment was no longer divided into subspaces abolished these errors entirely. Taken together, our results demonstrate that human spatial memory contains two separable representations of "where" an object can be found: (i) a schematic map of where an object lies with respect to local landmarks and boundaries; (ii) a representation of the identity of each local environment.
Meeting abstract presented at VSS 2016