Fact retrieval in younger and older adults: The role of mental models.

Using a fan effect paradigm, three experiments tested whether younger and older adults differ in the retrieval of integrated and nonintegrated facts, where integration refers to the development of a mental model. Earlier work by G. A. Radvansky and R. T. Zacks ( 1991) had found that as long as facts can be integrated into a single mental model, young adults show no increase in retrieval time or error rates as the size of the subset of related facts increases (i.e., no fan effect). The present studies how a similar pattern for older adults. By contrast, and in confirmation of our previous findings on age differences and the fan effect (L. D. Gerard, R. T. Zacks, L. Hasher, & G. A. Rad-vansky, 1991), older adults show an exaggerated fan effect, at least in their error rates, on subsets of related facts not easily integrated into a single mental model. The purpose of the present experiments is to assess how younger and older adults compare in the construction and use of mental models (e.g., Johnson-Laird, 1983, 1989). A mental model is a representation f a described situation rather than a representation of a text itself or the propositions conveyed by a text. The structure of a mental model corresponds to the func-