WHAT AND WHERE IN SPATIAL LANGUAGE AND SPATIAL COGNITION

Fundamental to spatial knowledge in all species are the representations underlying object recognition, object search, and navigation through space. But what sets humans apart from other species is our ability to express spatial experience through language. This target article explores the language of objects and places, asking what geometric properties are preserved in the representations underlying object nouns and spatial prepositions in English. Evidence from these two aspects of language suggests there are significant differences in the geometric richness with which objects and places are encoded. When an object is named (i.e., with count nouns), detailed geometric properties - principally the object's shape (axes, solid and hollow volumes, surfaces, and parts) - are represented. In contrast, when an object plays the role of either ''figure'' (located object) or ''ground'' (reference object) in a locational expression, only very coarse geometric object properties are represented, primarily the main axes. In addition, the spatial functions encoded by spatial prepositions tend to be nonmetric and relatively coarse, for example, ''containment'' ''contact,'' ''relative distance'' and ''relative direction.'' These properties are representative of other languages as well. The striking differences in the way language encodes objects versus places lead us to suggest two explanations: First, there is a tendency for languages to level out geometric detail from both object and place representations. Second, a nonlinguistic disparity between the representations of ''what'' and ''where'' underlies how language represents objects and places. The language of objects and places converges with and enriches our understanding of corresponding spatial representations.