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Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy

Electroencephalogram (EEG) power reductions in the aging brain have been described by numerous previous studies. However, the underlying mechanism for the observed brain signal power reduction remains unclear. One possible cause for reduced EEG signals in elderly subjects might be the increased dist...

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Autores principales: He, Mingjian, Liu, Feng, Nummenmaa, Aapo, Hämäläinen, Matti, Dickerson, Bradford C., Purdon, Patrick L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7929986/
https://www.ncbi.nlm.nih.gov/pubmed/33679380
http://dx.doi.org/10.3389/fnagi.2021.632310
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author He, Mingjian
Liu, Feng
Nummenmaa, Aapo
Hämäläinen, Matti
Dickerson, Bradford C.
Purdon, Patrick L.
author_facet He, Mingjian
Liu, Feng
Nummenmaa, Aapo
Hämäläinen, Matti
Dickerson, Bradford C.
Purdon, Patrick L.
author_sort He, Mingjian
collection PubMed
description Electroencephalogram (EEG) power reductions in the aging brain have been described by numerous previous studies. However, the underlying mechanism for the observed brain signal power reduction remains unclear. One possible cause for reduced EEG signals in elderly subjects might be the increased distance from the primary neural electrical currents on the cortex to the scalp electrodes as the result of cortical atrophies. While brain shrinkage itself reflects age-related neurological changes, the effects of changes in the distribution of electrical conductivity are often not distinguished from altered neural activity when interpreting EEG power reductions. To address this ambiguity, we employed EEG forward models to investigate whether brain shrinkage is a major factor for the signal attenuation in the aging brain. We simulated brain shrinkage in spherical and realistic brain models and found that changes in the conductor geometry cannot fully account for the EEG power reductions even when the brain was shrunk to unrealistic sizes. Our results quantify the extent of power reductions from brain shrinkage and pave the way for more accurate inferences about deficient neural activity and circuit integrity based on EEG power reductions in the aging population.
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spelling pubmed-79299862021-03-05 Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy He, Mingjian Liu, Feng Nummenmaa, Aapo Hämäläinen, Matti Dickerson, Bradford C. Purdon, Patrick L. Front Aging Neurosci Neuroscience Electroencephalogram (EEG) power reductions in the aging brain have been described by numerous previous studies. However, the underlying mechanism for the observed brain signal power reduction remains unclear. One possible cause for reduced EEG signals in elderly subjects might be the increased distance from the primary neural electrical currents on the cortex to the scalp electrodes as the result of cortical atrophies. While brain shrinkage itself reflects age-related neurological changes, the effects of changes in the distribution of electrical conductivity are often not distinguished from altered neural activity when interpreting EEG power reductions. To address this ambiguity, we employed EEG forward models to investigate whether brain shrinkage is a major factor for the signal attenuation in the aging brain. We simulated brain shrinkage in spherical and realistic brain models and found that changes in the conductor geometry cannot fully account for the EEG power reductions even when the brain was shrunk to unrealistic sizes. Our results quantify the extent of power reductions from brain shrinkage and pave the way for more accurate inferences about deficient neural activity and circuit integrity based on EEG power reductions in the aging population. Frontiers Media S.A. 2021-02-18 /pmc/articles/PMC7929986/ /pubmed/33679380 http://dx.doi.org/10.3389/fnagi.2021.632310 Text en Copyright © 2021 He, Liu, Nummenmaa, Hämäläinen, Dickerson and Purdon. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
He, Mingjian
Liu, Feng
Nummenmaa, Aapo
Hämäläinen, Matti
Dickerson, Bradford C.
Purdon, Patrick L.
Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title_full Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title_fullStr Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title_full_unstemmed Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title_short Age-Related EEG Power Reductions Cannot Be Explained by Changes of the Conductivity Distribution in the Head Due to Brain Atrophy
title_sort age-related eeg power reductions cannot be explained by changes of the conductivity distribution in the head due to brain atrophy
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7929986/
https://www.ncbi.nlm.nih.gov/pubmed/33679380
http://dx.doi.org/10.3389/fnagi.2021.632310
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