Influence of adult age on primary and secondary memory search

We compared young and elderly adults on the ability to search lists of words stored in primary memory (PM) and in secondary memory (SM). The results of Experiment 1 indicated that age differences in search performance were greatest under SM conditions. Older adults, unlike the young, appeared biased toward responding that probe items were not members of the memory sets stored in SM. As a result of this apparent bias, older adults committed a large number of errors on trials in which the probe was a member of the memorized list (i.e., positive probe trials) yet few errors on trials in which the probe was not a member of the list (i.e., negative probe trials). In addition, the responses of older, but not younger, adults to negative probe trials were found to be more rapid than were those to positive probe trials. In Experiment 2 we examined this pattern of responding and concluded that age differences were involved in the ability to encode memory sets and transfer them from PM to SM as well as in the ability to retrieve information from SM prior to conducting a memory search.