Retrieval from long-term memory does not bypass working memory.

Abstract

Information retrieved from long-term memory (LTM) enters working memory (WM), and the amount of information that can be retrieved is constrained to the limits of WM (about three to four items; Fukuda & Woodman, Proceedings of the National Academy of Sciences, 114 (20), 5306-5311, 2017). Can LTM retrieval occur when WM is near capacity, without consequence to either the retrieved or the maintained information? Liu, Li, Theeuwes, and Wang (NeuroImage, 261: 119513, 2022) presented evidence that even when WM is near capacity, LTM items could still be reported. They argue that retrieved LTM items can bypass WM. We investigated this further by introducing continuous reporting of retrieved information and WM contents to their paradigm. If retrieval bypasses WM, then there should be no impairment of report accuracy to either WM contents or LTM-retrieved information. In the first experiment, WM reports suffered when an LTM item was retrieved. In the second, we found that when WM was near capacity (four items), the fidelity of LTM reports suffered compared to when WM was not (two items or no items). Additionally, WM contents were reported with lower fidelity when an LTM item was retrieved compared to a WM-only condition, under both two-item and four-item WM load. We conclude that LTM retrieval does not bypass WM.