Stress enhances emotional memory-related theta oscillations in the medial temporal lobe

Hendrik Heinbockel, Conny W. E. M. Quaedflieg, Till R. Schneider, Andreas K. Engel, Lars Schwabe*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Stressful events impact memory formation, in particular for emotionally arousing stimuli. Although these stress effects on emotional memory formation have potentially far-reaching implications, the underlying neural mechanisms are not fully understood. Specifically, the temporal processing dimension of the mechanisms involved in emotional memory formation under stress remains elusive. Here, we used magnetoencephalography (MEG) to examine the neural processes underlying stress effects on emotional memory formation with high temporal and spatial resolution and a particular focus on theta oscillations previously implicated in mnemonic binding. Healthy participants (n = 53) underwent a stress or control procedure before encoding emotionally neutral and negative pictures, while MEG was recorded. Memory for the pictures was probed in a recognition test 24 h after encoding. In this recognition test, stress did not modulate the emotional memory enhancement but led to significantly higher confidence in memory for negative compared to neutral stimuli. Our neural data revealed that stress increased memory-related theta oscillations specifically in medial temporal and occipito-parietal regions. Further, this stress-related increase in theta power emerged during memory formation for emotionally negative but not for neutral stimuli. These findings indicate that acute stress can enhance, in the medial temporal lobe, oscillations at a frequency that is ideally suited to bind the elements of an ongoing emotional episode, which may represent a mechanism to facilitate the storage of emotionally salient events that occurred in the context of a stressful encounter.

Original languageEnglish
Article number100383
Number of pages12
JournalNeurobiology of Stress
Volume15
Early online date21 Aug 2021
DOIs
Publication statusPublished - Nov 2021

Keywords

  • ACTIVATION
  • ACUTE PSYCHOSOCIAL STRESS
  • DELETION VARIANT
  • Emotional memory
  • HIPPOCAMPUS
  • HUMAN AMYGDALA
  • MEG
  • Medial temporal lobe
  • Memory formation
  • RECOGNITION MEMORY
  • RESPONSES
  • SYNAPTIC PLASTICITY
  • Stress
  • VISUAL-CORTEX
  • WORKING-MEMORY

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