Overloading working memory at encoding impairs long-term memory gist retrieval in both older and younger adults, even under intentional learning conditions, challenging theories of relatively automatic gist encoding.
Key Findings
Results
LTM gist retrieval was reduced for objects encoded in sets exceeding working memory capacity in older adults.
Two older adult samples of n = 40 each were tested in Experiment 1.
Older adults, despite their generally enhanced reliance on gist memory, showed impaired LTM gist retrieval when encoding exceeded WM capacity.
This extends prior findings (previously shown in younger adults) to an older adult population.
The finding establishes a boundary condition for theories positing relatively automatic gist encoding even in populations known to rely more heavily on gist.
Results
Under intentional long-term learning instructions, LTM gist retrieval remained impaired by WM overload at encoding in both young and older adults.
Experiment 2 tested young adults (n = 81) and older adults (n = 40) under intentional long-term learning conditions.
Even when retaining items in LTM was made essential to participants, WM overloading at encoding still reduced gist retrieval.
Both age groups showed the same pattern, indicating the effect is not limited to incidental learning conditions.
This suggests that motivational or strategic factors cannot fully overcome the representational costs of WM overload.
Background
Encoding too many items into working memory limits subsequent long-term memory retrieval of both details and gist.
The paper builds on 'emerging evidence' that overloading WM at encoding impairs LTM for item details and gist.
The current work extends this boundary condition across age groups and learning intentions.
Results challenge leading memory theories that posit gist encoding occurs relatively automatically regardless of encoding load.
Conclusions
The findings challenge the universality of relatively automatic gist encoding posited by leading memory theories.
The authors state that 'Results invite leading memory theories to reconsider the universality of relatively automatic gist encoding.'
The boundary condition for automatic gist encoding extends to older adults and to intentional learning scenarios.
This represents a broader constraint on gist memory formation than previously recognized.
Greene N, Guitard D, Forsberg A, Cowan N, Naveh-Benjamin M. (2026). Long-term representational costs of overloading working memory.. Psychonomic bulletin & review. https://doi.org/10.3758/s13423-025-02826-y