MEDIATORS OF LONG-TERM-MEMORY PERFORMANCE ACROSS THE LIFE-SPAN

An individual-differences approach was used to examine the component p rocesses that predict episodic long-term memory performance. A total o f 301 participants ages 20-90 received a 7-hr cognitive battery across 3 days. Key constructs hypothesized to affect long-term memory functi on were assessed, including multiple measures of working memory and pe rceptual speed. Latent-construct, structural equation modeling was use d to examine the relationship of these measures and age to different t ypes of long-term memory tasks. Speed was a key construct for all 3 ty pes of memory tasks, mediating substantial age-related variance; worki ng memory was a fundamental construct for free and cued recall but not spatial memory. The data suggest that both speed and working memory a re fundamental to explaining age-related changes in cognitive aging bu t that the relative contributions of these constructs vary as a functi on of the type df memory task.