The flexibility of working memory in drawing on episodic long-term memory representations in serial recall.

Prior episodic long-term memory (LTM) can enhance working memory (WM) by improving recall of WM representations that match pre-learnt information and by freeing up capacity for new information. In this study, we investigated the flexibility of WM in doing so. Specifically, we tested whether WM can make use of pre-learnt item-item associations in a typical serial recall task, which requires item-positional bindings. We examined whether any benefits arise from accessing full episodic representations – leading to a reduction in memory load – or from item activation, where advantages align more with redintegration during test. Furthermore, we tested whether the benefits for pre-learnt and novel words depended on the position within the lists. Across three experiments, we consistently found that incorporating pre-learnt words into serial recall facilitated immediate memory for words that matched pre-learnt representations - speaking against an item activation account. However, the benefit on new words within lists that included pre-learnt pairs depended on whether the words could be easily submitted to encoding strategies, such as chunking or offloading, which was facilitated by providing matching grouping structures during encoding.