Core mechanisms underlying the long-term stability of working memory traces still work in aging

Working memory (WM) is the keystone of general cognitive achievement, but it declines with aging. The present study aims to investigate the consequence of WM deficits on the stability of WM traces over time. It has recently been proposed that long-term retention in younger adults is, at least in part, dependent on the total time during which each trace is under the control of attention in WM (Jarjat et al., 2018). In a complex span task, two factors aiming at varying the amount of attention available for maintaining WM traces were orthogonally manipulated: the cognitive load (CL) of the processing task and the number of distractors. A group of older participants performed this task and were tested for immediate and delayed recall. When compared to previous findings in young adults, older adults elicited lower immediate performance than younger adults, but only for a memory score that included stabilized traces. For delayed memory, younger adults outperformed older adults, but a similar pattern of results was observed in both groups. First, the two factors affected long-term memory performance to the same extent in young and older adults. Second, a non-linear relationship between delayed recall performance and the time accumulated for attentional maintenance between encoding and immediate recall was observed. This particular relationship did not differ from the one observed in young adults. These findings suggest that the core mechanisms underlying the long-term stability of WM traces still work in aging.