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A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness
Magnetoencephalography (MEG), a non-invasive technique for characterizing brain electrical activity, is gaining popularity as a tool for assessing group-level differences between experimental conditions. One method for assessing task-condition effects involves beamforming, where a weighted sum of fi...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3443237/ https://www.ncbi.nlm.nih.gov/pubmed/23024795 http://dx.doi.org/10.1371/journal.pone.0045084 |
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author | Gilbert, Jessica R. Shapiro, Laura R. Barnes, Gareth R. |
author_facet | Gilbert, Jessica R. Shapiro, Laura R. Barnes, Gareth R. |
author_sort | Gilbert, Jessica R. |
collection | PubMed |
description | Magnetoencephalography (MEG), a non-invasive technique for characterizing brain electrical activity, is gaining popularity as a tool for assessing group-level differences between experimental conditions. One method for assessing task-condition effects involves beamforming, where a weighted sum of field measurements is used to tune activity on a voxel-by-voxel basis. However, this method has been shown to produce inhomogeneous smoothness differences as a function of signal-to-noise across a volumetric image, which can then produce false positives at the group level. Here we describe a novel method for group-level analysis with MEG beamformer images that utilizes the peak locations within each participant’s volumetric image to assess group-level effects. We compared our peak-clustering algorithm with SnPM using simulated data. We found that our method was immune to artefactual group effects that can arise as a result of inhomogeneous smoothness differences across a volumetric image. We also used our peak-clustering algorithm on experimental data and found that regions were identified that corresponded with task-related regions identified in the literature. These findings suggest that our technique is a robust method for group-level analysis with MEG beamformer images. |
format | Online Article Text |
id | pubmed-3443237 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-34432372012-09-28 A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness Gilbert, Jessica R. Shapiro, Laura R. Barnes, Gareth R. PLoS One Research Article Magnetoencephalography (MEG), a non-invasive technique for characterizing brain electrical activity, is gaining popularity as a tool for assessing group-level differences between experimental conditions. One method for assessing task-condition effects involves beamforming, where a weighted sum of field measurements is used to tune activity on a voxel-by-voxel basis. However, this method has been shown to produce inhomogeneous smoothness differences as a function of signal-to-noise across a volumetric image, which can then produce false positives at the group level. Here we describe a novel method for group-level analysis with MEG beamformer images that utilizes the peak locations within each participant’s volumetric image to assess group-level effects. We compared our peak-clustering algorithm with SnPM using simulated data. We found that our method was immune to artefactual group effects that can arise as a result of inhomogeneous smoothness differences across a volumetric image. We also used our peak-clustering algorithm on experimental data and found that regions were identified that corresponded with task-related regions identified in the literature. These findings suggest that our technique is a robust method for group-level analysis with MEG beamformer images. Public Library of Science 2012-09-14 /pmc/articles/PMC3443237/ /pubmed/23024795 http://dx.doi.org/10.1371/journal.pone.0045084 Text en © 2012 Gilbert 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, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Gilbert, Jessica R. Shapiro, Laura R. Barnes, Gareth R. A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title | A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title_full | A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title_fullStr | A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title_full_unstemmed | A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title_short | A Peak-Clustering Method for MEG Group Analysis to Minimise Artefacts Due to Smoothness |
title_sort | peak-clustering method for meg group analysis to minimise artefacts due to smoothness |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3443237/ https://www.ncbi.nlm.nih.gov/pubmed/23024795 http://dx.doi.org/10.1371/journal.pone.0045084 |
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