ERPS DURING STUDY AS A FUNCTION OF SUBSEQUENT DIRECT AND INDIRECT MEMORY TESTING IN YOUNG AND OLD ADULTS

Event-related potentials (ERPs) were recorded from young and older adu lts while words were studied during structural and semantic encoding t asks. Items were presented twice to assess repetition effects. Subsequ ent memory effects (i.e. Dm or difference in subsequent memory) associ ated with non-target study items were also evaluated. Memory for non-t arget study items was tested either indirectly (word stem completion) or directly (cued recall). There were small, but unreliable age differ ences (favoring the young) on both the indirect and direct tests. Thes e small differences were consistent with previous results for stem com pletion performance, but were counter to expectation for the cued reca ll test, where young adults were expected to show clear superiority. W e conclude, based on task considerations, that for cued recall, subjec ts may have adopted an 'implicit' retrieval strategy. Because older ad ults typically have little difficulty with implicit retrieval, they fa red almost as well as the young on cued recall. Dm effects were reliab le for the young only. As Dm is thought to reflect elaborative encodin g processes, the larger Dm magnitudes in the young than the old sugges t that the small, though unreliable, age-related performance differenc es that resulted may have been mediated by such elaborative processing on the part of the younger adults.