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Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra

Alpha blocking, a phenomenon where the alpha rhythm is reduced by attention to a visual, auditory, tactile or cognitive stimulus, is one of the most prominent features of human electroencephalography (EEG) signals. Here we identify a simple physiological mechanism by which opening of the eyes causes...

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Autores principales: Hartoyo, Agus, Cadusch, Peter J., Liley, David T. J., Hicks, Damien G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7217488/
https://www.ncbi.nlm.nih.gov/pubmed/32352973
http://dx.doi.org/10.1371/journal.pcbi.1007662
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author Hartoyo, Agus
Cadusch, Peter J.
Liley, David T. J.
Hicks, Damien G.
author_facet Hartoyo, Agus
Cadusch, Peter J.
Liley, David T. J.
Hicks, Damien G.
author_sort Hartoyo, Agus
collection PubMed
description Alpha blocking, a phenomenon where the alpha rhythm is reduced by attention to a visual, auditory, tactile or cognitive stimulus, is one of the most prominent features of human electroencephalography (EEG) signals. Here we identify a simple physiological mechanism by which opening of the eyes causes attenuation of the alpha rhythm. We fit a neural population model to EEG spectra from 82 subjects, each showing a different degree of alpha blocking upon opening of their eyes. Though it has been notoriously difficult to estimate parameters by fitting such models, we show how, by regularizing the differences in parameter estimates between eyes-closed and eyes-open states, we can reduce the uncertainties in these differences without significantly compromising fit quality. From this emerges a parsimonious explanation for the spectral differences between states: Changes to just a single parameter, p(ei), corresponding to the strength of a tonic excitatory input to the inhibitory cortical population, are sufficient to explain the reduction in alpha rhythm upon opening of the eyes. We detect this by comparing the shift in each model parameter between eyes-closed and eyes-open states. Whereas changes in most parameters are weak or negligible and do not scale with the degree of alpha attenuation across subjects, the change in p(ei) increases monotonically with the degree of alpha blocking observed. These results indicate that opening of the eyes reduces alpha activity by increasing external input to the inhibitory cortical population.
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spelling pubmed-72174882020-05-29 Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra Hartoyo, Agus Cadusch, Peter J. Liley, David T. J. Hicks, Damien G. PLoS Comput Biol Research Article Alpha blocking, a phenomenon where the alpha rhythm is reduced by attention to a visual, auditory, tactile or cognitive stimulus, is one of the most prominent features of human electroencephalography (EEG) signals. Here we identify a simple physiological mechanism by which opening of the eyes causes attenuation of the alpha rhythm. We fit a neural population model to EEG spectra from 82 subjects, each showing a different degree of alpha blocking upon opening of their eyes. Though it has been notoriously difficult to estimate parameters by fitting such models, we show how, by regularizing the differences in parameter estimates between eyes-closed and eyes-open states, we can reduce the uncertainties in these differences without significantly compromising fit quality. From this emerges a parsimonious explanation for the spectral differences between states: Changes to just a single parameter, p(ei), corresponding to the strength of a tonic excitatory input to the inhibitory cortical population, are sufficient to explain the reduction in alpha rhythm upon opening of the eyes. We detect this by comparing the shift in each model parameter between eyes-closed and eyes-open states. Whereas changes in most parameters are weak or negligible and do not scale with the degree of alpha attenuation across subjects, the change in p(ei) increases monotonically with the degree of alpha blocking observed. These results indicate that opening of the eyes reduces alpha activity by increasing external input to the inhibitory cortical population. Public Library of Science 2020-04-30 /pmc/articles/PMC7217488/ /pubmed/32352973 http://dx.doi.org/10.1371/journal.pcbi.1007662 Text en © 2020 Hartoyo et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Hartoyo, Agus
Cadusch, Peter J.
Liley, David T. J.
Hicks, Damien G.
Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title_full Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title_fullStr Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title_full_unstemmed Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title_short Inferring a simple mechanism for alpha-blocking by fitting a neural population model to EEG spectra
title_sort inferring a simple mechanism for alpha-blocking by fitting a neural population model to eeg spectra
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7217488/
https://www.ncbi.nlm.nih.gov/pubmed/32352973
http://dx.doi.org/10.1371/journal.pcbi.1007662
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