Relative contribution of associative memory and working memory to subjective organisation in aging

Organising information is an efficient way to improve episodic memory performance. When the information is not semantically related to each other, individuals can self-organize this information. This spontaneous subjective organisation involves important working memory (WM) resources and is negatively affected by aging, potentially because it also relies on associative memory. Here, we examined whether such subjective organisation involves associative processes, whether this relation is explained by WM capacity, and whether this relationship differs with age. We tested 40 young (non-students) adults and 40 older adults on two memory tasks: one allowing for subjective organisation to be implemented and another accounting for associative memory processes. These participants also performed three different WM tasks to compute a WM capacity index. Whilst reporting classical age-related effects on recall, recognition and WM performance, we found that both associative memory and WM are related to subjective organisation in both young and older adults. However, between these two factors, WM capacity was the main factor explaining subjective performance in both age groups, though to a greater extent in young adults. These results confirm the central role of WM in episodic memory, particularly in explaining the age-related decline of this function.