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Probing the relevance of the hippocampus for conflict-induced memory improvement
The hippocampus plays a key role for episodic memory. In addition, a small but growing number of studies has shown that it also contributes to the resolution of response conflicts. It is less clear how these two functions are related, and how they are affected by hippocampal lesions in patients with...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Academic Press
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836234/ https://www.ncbi.nlm.nih.gov/pubmed/33189928 http://dx.doi.org/10.1016/j.neuroimage.2020.117563 |
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author | Ramm, Markus Sundermann, Benedikt Gomes, Carlos Alexandre Möddel, Gabriel Langenbruch, Lisa Nayyeri, Mahboobeh Dehghan Young, Peter Pfleiderer, Bettina Krebs, Ruth M. Axmacher, Nikolai |
author_facet | Ramm, Markus Sundermann, Benedikt Gomes, Carlos Alexandre Möddel, Gabriel Langenbruch, Lisa Nayyeri, Mahboobeh Dehghan Young, Peter Pfleiderer, Bettina Krebs, Ruth M. Axmacher, Nikolai |
author_sort | Ramm, Markus |
collection | PubMed |
description | The hippocampus plays a key role for episodic memory. In addition, a small but growing number of studies has shown that it also contributes to the resolution of response conflicts. It is less clear how these two functions are related, and how they are affected by hippocampal lesions in patients with mesial temporal lobe epilepsy (MTLE). Previous studies suggested that conflict stimuli might be better remembered, but whether the hippocampus is critical for supporting this interaction between conflict processing and memory formation is unknown. Here, we tested 19 patients with MTLE due to hippocampal sclerosis and 19 matched healthy controls. Participants performed a face-word Stroop task during functional magnetic resonance imaging (fMRI) followed by a recognition task for the faces. We tested whether memory performance and activity in brain regions implicated in long-term memory were modulated by conflict during encoding, and whether this differed between MTLE patients and controls. In controls, we largely replicated previous findings of improved memory for conflict stimuli. While MTLE patients showed response time slowing during conflict trials as well, they did not exhibit a memory benefit. In controls, neural activity of conflict resolution and memory encoding interacted within a hippocampal region of interest. Here, left hippocampal recruitment was less efficient for memory performance in incongruent trials than in congruent trials, suggesting an intrahippocampal competition for limited resources. They also showed an involvement of precuneus and posterior cingulate cortex during conflict resolution. Both effects were not observed in MTLE patients, where activation of the precuneus and posterior cingulate cortex instead predicted later memory. Further research is needed to find out whether our findings reflect widespread functional reorganization of the episodic memory network due to hippocampal dysfunction. |
format | Online Article Text |
id | pubmed-7836234 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Academic Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-78362342021-02-01 Probing the relevance of the hippocampus for conflict-induced memory improvement Ramm, Markus Sundermann, Benedikt Gomes, Carlos Alexandre Möddel, Gabriel Langenbruch, Lisa Nayyeri, Mahboobeh Dehghan Young, Peter Pfleiderer, Bettina Krebs, Ruth M. Axmacher, Nikolai Neuroimage Article The hippocampus plays a key role for episodic memory. In addition, a small but growing number of studies has shown that it also contributes to the resolution of response conflicts. It is less clear how these two functions are related, and how they are affected by hippocampal lesions in patients with mesial temporal lobe epilepsy (MTLE). Previous studies suggested that conflict stimuli might be better remembered, but whether the hippocampus is critical for supporting this interaction between conflict processing and memory formation is unknown. Here, we tested 19 patients with MTLE due to hippocampal sclerosis and 19 matched healthy controls. Participants performed a face-word Stroop task during functional magnetic resonance imaging (fMRI) followed by a recognition task for the faces. We tested whether memory performance and activity in brain regions implicated in long-term memory were modulated by conflict during encoding, and whether this differed between MTLE patients and controls. In controls, we largely replicated previous findings of improved memory for conflict stimuli. While MTLE patients showed response time slowing during conflict trials as well, they did not exhibit a memory benefit. In controls, neural activity of conflict resolution and memory encoding interacted within a hippocampal region of interest. Here, left hippocampal recruitment was less efficient for memory performance in incongruent trials than in congruent trials, suggesting an intrahippocampal competition for limited resources. They also showed an involvement of precuneus and posterior cingulate cortex during conflict resolution. Both effects were not observed in MTLE patients, where activation of the precuneus and posterior cingulate cortex instead predicted later memory. Further research is needed to find out whether our findings reflect widespread functional reorganization of the episodic memory network due to hippocampal dysfunction. Academic Press 2021-02-01 /pmc/articles/PMC7836234/ /pubmed/33189928 http://dx.doi.org/10.1016/j.neuroimage.2020.117563 Text en © 2020 The Authors http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Article Ramm, Markus Sundermann, Benedikt Gomes, Carlos Alexandre Möddel, Gabriel Langenbruch, Lisa Nayyeri, Mahboobeh Dehghan Young, Peter Pfleiderer, Bettina Krebs, Ruth M. Axmacher, Nikolai Probing the relevance of the hippocampus for conflict-induced memory improvement |
title | Probing the relevance of the hippocampus for conflict-induced memory improvement |
title_full | Probing the relevance of the hippocampus for conflict-induced memory improvement |
title_fullStr | Probing the relevance of the hippocampus for conflict-induced memory improvement |
title_full_unstemmed | Probing the relevance of the hippocampus for conflict-induced memory improvement |
title_short | Probing the relevance of the hippocampus for conflict-induced memory improvement |
title_sort | probing the relevance of the hippocampus for conflict-induced memory improvement |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836234/ https://www.ncbi.nlm.nih.gov/pubmed/33189928 http://dx.doi.org/10.1016/j.neuroimage.2020.117563 |
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