Aging and retrieval of words in semantic memory.

Twenty-four young and 24 old adults participated in a lexical decision task (Study 1) in which they judged whether letter strings were words. No age differences were found in either accuracy or response latency. In Study 2 18 young and 18 old adults participated in a word retrieval study in which the stimulus was the definition of a target word and the task was to name the word that was defined. Younger adults were superior in word retrieval as measured by both number of successful retrievals and response latency. The discrepancy between the two sets of results is attributed to differences in retrieval requirements, which are interpreted within the framework of a two-component model of semantic memory. It is suggested that older adults have a specific deficit in accessing word-name information in an orthographically organized lexical network given stimulus information that is conceptual rather than orthographic.