The "Map in the Head" Metaphor

The "Map in the Head" metaphor states that knowledge of large-scale space is isomorphic to the information stored in a graphical map: That is, corresponding operations are used to store and retrieve information. The purpose of this essay is to look carefully at the "Map in the Head" metaphor to see the limits of its applicability. There are two types of experimental results that are difficult to accommodate within this metaphor. First, instead of being integrated into a single map, spatial knowledge can fall into disconnected components, with little or no relation between the components. Second, knowledge of routes (and other spatial facts) may be represented asymmetrically, so that a route can be followed in one direction but not in the other. The first set of results leads us to replace the simple "Map in the Head" with a more complex and sophisticated metaphor including separate metrical and topological components. The second set of results suggests that even the more sophisticated "Map in the Head" is built from computational structures that occasionally reveal their nonmaplike properties. A computational model is presented for assimilating observations gathered during travel, first into a description of the particular route, then into representations for the topological and metrical features of the environment.