Executive control contributes little to prospective memory function in older age: evidence from more ecologically valid paradigms.

Abstract

Age-related losses in executive control are widely assumed to contribute to prospective memory (PM) lapses in late adulthood, but to date, this assumption has gained only inconsistent support from lab-based studies. The present study tested whether age indirectly affects PM via (1) individual differences in specific executive control operations (a parallel mediated model), or (2) a serially mediated model, with processing speed as the first mediator. Older adults (n = 166) completed four measures of PM that had higher ecological validity than standard lab-based paradigms, as well as measures of executive function and other cognitive abilities. The results showed that, although age was a significant predictor of reduced performance on three of the PM measures, particularly time-based tasks, these negative age associations were only slightly diminished when executive functions were controlled for. Performance on the PM task with the greatest ecological validity (MEMO) was independent of age and measures of executive function but positively related to both learning and retention. Processing speed was a poor predictor of PM performance on all measures (accounting for between 0% and 4% of variance). Taken together, these results highlight the need for circumspection in generalising the role of executive control in age-related prospective memory performance.