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

Abstract

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.

Keywords:

• retrieval-induced forgetting
• aging
• warnings
• associative learning

Acknowledgment

We would like to acknowledge the assistance of Nicholas J. Martin, Barbara J. Wright, Melissa Cavins, Meredith Knight, Joshlyn Shareck, Alan Harrison, Jessica Floyd, Brittany Sentell, Jessica Hays, and Kenneth Hammett in data collection and preparation.

Notes

^1. We examined whether there were differences in education levels across the two age groups or conditions in Experiment 1 that could yield differences in performance. The older adults had achieved significantly more education than younger adults, F(1, 205) = 68.05, p < 0.001,  = 0.25. However, no differences in education were found across or within conditions for either age group, p > 0.05.

^2. Approximately 85% of our older adult participants were recruited from the chapter of the Osher Lifelong Learning Institute (OLLI) on the University of Alabama in Huntsville campus. OLLI members tend to be slightly more cognitively and physically active than the general population of older adults, given that they are well enough to drive to and attend weekly OLLI meetings and continuing education classes.

^3. We analyzed the number of times participants within each age group and condition heard the warning before answering the manipulation check question correctly. The number of times it was necessary to present the warning decreased across parts, but did not differ as a function of condition or age group, and there was no difference in either part in impairment effects as a function of the number of times participants heard the warning.

^4. For completeness, we assessed whether there were age differences in performance on the distractor tasks in Experiment 1. On both the Digit Symbol Substitution Task (maximum score 35; Jackson, 1984) and the Digit Span Task (maximum score 158; Wechsler, 1997), younger adults scored significantly higher than older adults (Younger: M = 30.50, SE = 0.42 and M = 109.14, SE = 2.26; Older: M = 22.08, SE = 0.52 and M = 79.13, SE = 3.33), p < 0.05.

^5. Using category cues (e.g., FRUIT) rather than category cues with exemplar stems (e.g., FRUIT – O____) during the recall phases removed our ability to investigate whether the underlying mechanism is inhibitory or noninhibitory, but ensured we would obtain impairment effects in our baseline condition (see Anderson et al., 1994, for this argument), which was critical for asking whether warnings would counteract these effects.

^6. When calculating impairment effects, the results are often negative numbers, reflecting lower recall of Rp− items than Nrp items. Throughout the manuscript, we have focused on the absolute value, removing the minus signs, to enhance clarity.

^7. As in Experiment 1, no differences in education were found across conditions, p > 0.05.