BASING CATEGORIZATION ON INDIVIDUALS AND EVENTS

Exemplar, prototype, and connectionist models typically assume that ev ents constitute the basic unit of learning and representation in categ orization. In these models, each learning event updates a statistical representation of a category independently of other learning events. A n implication is that events involving the same individual affect lear ning independently and are not integrated into a single structure that represents the individual in an internal model of the world. A series of experiments demonstrates that human subjects track individuals acr oss events, establish representations of them, and use these represent ations in categorization. These findings are consistent with ''represe ntationalism,'' the view that an internal model of the world constitut es a physical level of representation in the brain, and that the brain does not simply capture the statistical properties of events in an un differentiated dynamical system.-Although categorization is an inheren tly statistical process that produces generalization, pattern completi on, frequency effects, and adaptive learning, it is also an inherently representational process that establishes an internal model of the wo rld. As a result, representational structures evolve in memory to trac k the histories of individuals, accumulate information about them, and simulate them in events, (C) 1998 Academic Press.