Recall of subject-performed tasks, verbal tasks, and cognitive activities across the adult life span:: Parallel age-related deficits

Motor activity during encoding of verbal information has been suggested to reduce age differences in episodic memory. Here we examined memory for sentences encoded with enactment (SPTs, subject-performed tasks) or without enactment (VTs, verbal tasks) in a population-based sample consisting of 10 groups ranging in age from 35 to 80 years (N=1000). Memory performance was assessed by immediate free- and category-cued recall. Degree of clustering was measured by the adjusted ratio of clustering score. Recall of cognitive activities served as a complementary measure of memory for performed tasks. Sentence recall showed a gradual decline across age, of about the same magnitude for SPTs and VTs, in both free and cued recall. Clustering in free recall was higher for SPTs than for VTs, but there were no age differences in clustering. A pattern of gradual decline from age 35 was observed also in activity recall, regardless of whether the activities involved motor activity or not. Across the memory measures, differences in education accounted for all of the age-related variance in performance among the younger (35-55 years) but not the older groups (60-80 years), suggesting that genuine aging effects in these measures are more prominent in old age. Together, the results indicate that age differences in episodic memory, in line with most, if not all, types of encoding support, generalize across the performed/non-performed distinction.