The role of warnings in younger and older adults' retrieval-induced forgetting.

Retrieval-induced forgetting (RIF) is a phenomenon wherein practicing recalling some items impairs recall of semantically related, unpracticed items. Two experiments examined whether explicitly warning older (Experiment 1) and younger adults (Experiments 1 and 2) about RIF at different times during two exposures to the retrieval-practice paradigm would affect participants' forgetting. Participants in both experiments were either warned before encoding, retrieval-practice, recall, or not at all. The warning was combined with integration instructions in Experiment 2. Warnings did not reduce forgetting in either age group in Experiment 1. Forgetting increased across exposures in most cases and older adults experienced more forgetting than did younger adults. Combining integration instructions with the warning also did not reduce younger adults' forgetting relative to baseline conditions in Experiment 2. Results indicate that both younger and older adults are susceptible to retrieval-induced forgetting and that raising awareness of the phenomenon increases rather than decreases forgetting rates.