Older adults show deficits in retrieving and decoding associative mediators generated at study.

Abstract

We instructed the use of mediators to encode paired-associate items, and then measured both cued recall of targets and mediators. Older adults (n = 49) and younger adults (n = 57) studied a mixed list of concrete and abstract noun pairs under instructions to either generate a sentence or an image to form a new association between normatively unrelated words. After each item was studied, they reported the mediator, if any, they had generated. After standard cued recall for each item, they were asked to recall their mediator. Large age differences (d = 1.52) occurred in mediator retrieval during a cued recall test. Older adults were less likely to retrieve mediators, and when they did, their retrieved mediators were more often gist-consistent than verbatim retrievals. Older adults were also more likely to report the wrong target word when correctly retrieving the mediator. Age differences in these decoding errors were large statistical effects, especially for abstract items (d = 1.41) relative to concrete items (d = 0.54). Older adults' associative memory deficits have more to do with retrieval mechanisms than with inadequate encoding strategies.