Inconsistency in spatial knowledge

Two experiments examined whether spatial information judged from cognitive maps contains the functional euclidean properties of real maps. In Experiment 1, the six directions between sets of threetriad locations in a town were judged from memory. The angle formed by the two judged directions from a location to the other two locations in a triad was derived. The three derived angles of a triad were then summed. The derived angles were found to be biased toward 90 deg. The sum of the three derived angles of a triad also exceeded 180 deg, which violates the euclidean properties of real maps. In Experiment 2, subjects judged the direction between pairs of American cities in both directions. The judged directions were found to be consistently nonreversible, which is contrary to the properties of euclidean geometry. The study suggests that information judged from cognitive maps can contain internally inconsistent spatial properties, and the results are discussed in terms of current theories of spatial representation.