Phonological and lexical-semantic short-term memory and their relationship to sentence production in older adults

Evidence from brain-damaged patients suggests a link between lexical-semantic retention capacity and sentence production. The present study seeks to establish whether lexical-semantic retention capacity changes with normal aging, and whether individual differences in this capacity predict the degree of increased difficulty older speakers have producing sentences with two-noun initial phrases, relative to those with one-noun initial phrases, elicited in a picture naming task. Older adults performed significantly better than younger adults on one of two tests of lexical-semantic retention, and performed similarly to younger adults on tests of phonological retention. Lexical-semantic capacity, but not phonological capacity, predicted the size of the initial phrase complexity effect in older adults. Results suggest that lexical-semantic retention ability is preserved in normal aging and does play a role in sentence production.