It is well known that memory declines with advancing age. However, the reasons for this impairment in memory are not understood (Burke & Light, 1981). One explanation that has gained currency is that older adults do not process the meaning of new information as effectively as young adults because of reduced processing resources or attentional capacity (e.g., Cohen, 1979, 1981; Craik & Byrd, 1982; Craik & Rabinowitz, 1984; Eysenck, 1974; Hasher & Zacks, 1979; Perlmutter, 1978; Simon, 1979; Till & Walsh, 1980). This explanation presupposes that there are age-related differences in comprehension of word meanings. The bulk of the research in this area has not, however, produced results in accordance with this position (see Light, 1988, for a review). For instance, there is little evidence for age-related declines in vocabulary (Schaie, 1980). The organization of meanings in semantic memory, as indexed by responses on word association tasks, appears to be stable in adulthood (e.g., Burke & Peters, 1986; Howard, 1980). Also, studies of semantic priming in lexical decision tasks find no qualitative differences in the nature of activation of meanings in semantic memory (e.g., Burke & Yee, 1984; Howard, this volume).

Despite these negative findings, there has been a recent spate of suggestions that older adults may experience language comprehension problems (see Burke and Light, 1981; Hartley, Harker, and Walsh, 1980; Hultsch and Dixon, 1984; and Salthouse, 1982, for reviews).