Effect of Aging On Implicit and Explicit Memory for New Associations

Thirty-two young and 32 elderly subjects were asked to study 24 unrelated cue-target pairs of words. Two kinds of study tasks, sentence evaluation vs sentence generation, were used in a between-subject design. In the sentence generation task, subjects were asked to generate a sentence that linked the two members of each pair. In the sentence evaluation task, subjects were shown sentences that included the target pairs and asked to assess how well these sentences related the targets to each other. This was followed by an implicit memory test (word-stem completion) and an explicit cued-recall test. In both tests, the target word was presented alone or associated with the same word or a new cue word (context) as the one used in the study stage. Firstly, in all conditions of both tests, the young subjects performed better than the elderly. Secondly, study-by-generation led to a better memory score than study-by-evaluation for the same-context condition in the implicit test, and for the young subjects in the explicit test. Thirdly, the same-context condition led to a better score than the remaining two conditions in each subgroup of the cued-recall test, and in the completion test after study-by-generation only; after study-by-evaluation, the same-context condition did not differ from the new-context condition