Stress disrupts insight-driven mnemonic reconfiguration in the medial temporal lobe

TY - JOUR

T1 - Stress disrupts insight-driven mnemonic reconfiguration in the medial temporal lobe

AU - Grob, Anna-Maria

AU - Milivojevic, Branka

AU - Alink, Arjen

AU - Doeller, Christian F

AU - Schwabe, Lars

N1 - Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.

PY - 2023/1

Y1 - 2023/1

N2 - Memories are not stored in isolation. Insight into the relationship of initially unrelated events may trigger a flexible reconfiguration of the mnemonic representation of these events. Such representational changes allow the integration of events into coherent episodes and help to build up-to-date-models of the world around us. This process is, however, frequently impaired in stress-related mental disorders resulting in symptoms such as fragmented memories in PTSD. Here, we combined a real life-like narrative-insight task, in which participants learned how initially separate events are linked, with fMRI-based representational similarity analysis to test if and how acute stress interferes with the insight-driven reconfiguration of memories. Our results showed that stress reduced the activity of medial temporal and prefrontal areas when participants gained insight into the link between events. Moreover, stress abolished the insight-related increase in representational dissimilarity for linked events in the anterior part of the hippocampus as well as its association with measures of subsequent memory that we observed in non-stressed controls. However, memory performance, as assessed in a forced-choice recognition test, was even enhanced in the stress group. Our findings suggest that acute stress impedes the neural integration of events into coherent episodes but promotes long-term memory for these integrated narratives and may thus have implications for understanding memory distortions in stress-related mental disorders.

AB - Memories are not stored in isolation. Insight into the relationship of initially unrelated events may trigger a flexible reconfiguration of the mnemonic representation of these events. Such representational changes allow the integration of events into coherent episodes and help to build up-to-date-models of the world around us. This process is, however, frequently impaired in stress-related mental disorders resulting in symptoms such as fragmented memories in PTSD. Here, we combined a real life-like narrative-insight task, in which participants learned how initially separate events are linked, with fMRI-based representational similarity analysis to test if and how acute stress interferes with the insight-driven reconfiguration of memories. Our results showed that stress reduced the activity of medial temporal and prefrontal areas when participants gained insight into the link between events. Moreover, stress abolished the insight-related increase in representational dissimilarity for linked events in the anterior part of the hippocampus as well as its association with measures of subsequent memory that we observed in non-stressed controls. However, memory performance, as assessed in a forced-choice recognition test, was even enhanced in the stress group. Our findings suggest that acute stress impedes the neural integration of events into coherent episodes but promotes long-term memory for these integrated narratives and may thus have implications for understanding memory distortions in stress-related mental disorders.

KW - Humans

KW - Memory

KW - Temporal Lobe/diagnostic imaging

KW - Hippocampus/diagnostic imaging

KW - Magnetic Resonance Imaging

KW - Memory Disorders

KW - Memory, Episodic

KW - Mental Recall

U2 - 10.1016/j.neuroimage.2022.119804

DO - 10.1016/j.neuroimage.2022.119804

M3 - SCORING: Journal article

C2 - 36503160

VL - 265

SP - 119804

JO - NEUROIMAGE

JF - NEUROIMAGE

SN - 1053-8119

ER -