Semantic and episodic contributions of long-term memory to working memory in young and older adults

Previous research has shown that episodic and semantic long-term memory (LTM) can support working memory (WM) performance in young adults. When remembering word pairs, performance improves when pairs have been previously learned (episodic LTM) or are semantically related (semantic LTM, e.g., table-chair). However, these types of LTM support are typically examined in isolation, and it remains unclear whether they contribute to WM via distinct mechanisms or whether their roles change with age. Across three experiments, younger and older adults completed word-pair WM tasks that independently manipulated episodic and semantic LTM support (Experiment 1a: N = 56 younger adults, N = 56 older adults; Experiment 1b: N = 55 younger adults; Experiment 2: N = 59 younger adults, N = 60 older adults). We examined whether older adults may benefit from both forms of LTM within the same task, how episodic and semantic support interact, and which mechanisms underlie the semantic benefit to WM. The results show that both younger and older adults reliably benefited from episodic LTM support. Semantic relatedness also improved WM performance across age groups. Critically, analyses targeting underlying mechanisms indicated that the semantic benefit arose from facilitated formation of episodic traces within the activated portion of LTM, rather than from strengthened bindings maintained within WM itself. Together, these findings demonstrate that WM flexibly draws on episodic and semantic LTM and that this capacity remains largely intact in older adulthood. (PsycInfo Database Record (c) 2026 APA, all rights reserved).