# Long-term representational costs of overloading working memory

## TL;DR

Learning too much at once can hurt long-term memory, even when trying to remember the main ideas, in both young and older adults.

## Contribution

Shows that overloading working memory impairs gist-based long-term memory, even in older adults and under intentional learning.

## Key findings

- Older adults show reduced gist retrieval when working memory is overloaded.
- Young and older adults both show impaired gist retrieval under intentional learning with WM overload.
- The effect challenges theories of automatic gist encoding.

## Abstract

Can learning too much information at once impair long-term retention of its meaning? Emerging evidence suggests that encoding too many items into working memory (WM) limits subsequent long-term memory (LTM) retrieval of their details and gist. These findings highlight a boundary condition for theories positing relatively automatic gist encoding. But how expansive is this boundary? Experiment 1 shows that it extends to older adults, despite their generally enhanced reliance on gist memory. In two older adult samples (n = 40 each), LTM gist retrieval was reduced for objects encoded in sets exceeding WM capacity. Experiment 2 shows that this boundary holds even when retaining items in LTM is essential. Under intentional long-term learning, young (n = 81) and older (n = 40) adults’ LTM gist retrieval remained affected by overloading WM at encoding. Results invite leading memory theories to reconsider the universality of relatively automatic gist encoding.

The online version contains supplementary material available at 10.3758/s13423-025-02826-y.