Adult age differences in storage-retrieval processes: A stages-of-learning analysis of developmental interactions in concreteness effects.

In standard list-learning experiments, Age × Treatment interactions have been regarded as an important source of information regarding the locus (storage/retrieval) of age-related memory deficits in adulthood. Unfortunately, these interactions may be spurious byproducts of the use of fixed-trials designs in which age and completeness of learning are confounded. In this paper, we report two experiments in which these problems were explored in the context of item concreteness effects in young and old adults' free recall. In each experiment, eighty 20-year-olds and forty-two 70-year-olds memorized a 16-item list to a stringent acquisition criterion. The manipulations were pictures versus words (Exp. 1) and concrete versus abstract nouns (Exp. 2). The data were analyzed using a recently developed two-stage model that delivers numerical estimates of the impact of these manipulations on the storage and retrieval components of recall. For Experiment 1, the results showed that: (a) for young adults, pictures were easier to store and retrieve than words; (b) for old adults, there was a pictorial superiority effect at storage but a marked pictorial inferiority effect at retrieval; and (c) although younger adults were better than older adults at storing pictures and words and at retrieving pictures, older adults were better than younger adults at retrieving words. For Experiment 2, the results showed that: (a) on average, concrete words were easier to store and retrieve than abstract words at both age levels; and (b) on average, although younger adults were better than older adults at storing concrete and abstract words and at retrieving abstract words, older adults were better than younger adults at retrieving concrete words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)