Polysemy - the existence of multiple but related meanings for a single form - has always been problematic for purely structural accounts of meaning. When it is viewed from a cognitive perspective, however, it emerges as a natural, indeed necessary consequence of the human ability to think flexibility. If we synthesize three approaches: John Anderson's theory of cognitive architecture, Sperber and Wilson's concept of relevance, and Lakoff and Johnson's theory of image schemas, it is possible to account for many of the properties of polysemy. Essentially, polysemy is an effect of relevance: of the human ability to select the interpretation which maximizes useful information while minimizing processing cost.

An account in these terms helps to address a number of unresolved problems. Polysemy has been problematic because it seemed to fall on the border between category identity and category distinctness. This gradient can be treated in terms of relevance: two items belong to distinct categories only to the extent that shared information is relevant and contrasting information is irrelevant. Polysemy also displays clear asymmetries both in its distribution and in its interaction with anaphoric phenomena. These can be explained by asymmetries of activation spread through image schematic structure; where activation spread is facilitated, processing costs are lowered, increasing relevance, and hence facilitating both polysemy and the recovery of anaphoric reference.