Current Biology
Volume 31, Issue 23, 6 December 2021, Pages 5204-5213.e8
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Article
The memory trace of a stressful episode

https://doi.org/10.1016/j.cub.2021.09.044Get rights and content
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open access

Highlights

  • Psychosocial stress shapes representations of memory traces in the human amygdala

  • Neural representations of central items of a stressful episode are bound together

  • Representations of remembered central items bind to representations of the stressor

  • Amygdala similarity patterns explain how stress improves memory for central items

Summary

Stress influences episodic memory formation via noradrenaline and glucocorticoid effects on amygdala and hippocampus. A common finding is the improvement of memory for central aspects of a stressful episode. This is putatively related to changes in the neural representations of specific experiences, i.e., their memory traces. Here we show that the memory improvement for objects that were encountered in a stressful episode relates to differences in the neural representations of these objects in the amygdala. Using functional magnetic resonance imaging, we found that stress specifically altered the representations of central objects: compared to control objects, they became more similar to one another and more distinct from objects that were not part of this episode. Furthermore, higher similarity of central objects to the main stressor—the faces of the stress-inducing committee members—predicted better memory. This suggests that the central objects were closely integrated into a stressor-centered memory representation. Our findings provide mechanistic insights into how stress shapes the memory trace and have profound implications for neurocognitive models of stressful and emotional memory.

Keywords

episodic memory
stress
emotion
fMRI
Trier social stress test
neural representations
amygdala

Data and code availability

All data and original code has been deposited at Open Science Framework and is publicly available as of the date of publication. DOIs are listed in the key resources table. Any additional information required to reanalyze the data reported in this paper is available from the lead contact upon request.

Cited by (0)

4

These authors contributed equally

5

Lead contact