Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods

The human brain can be divided into multiple areas, each responsible for different aspects of behaviour. Healthy brain function relies upon efficient connectivity between these areas and, in recent years, neuroimaging has been revolutionised by an ability to estimate this connectivity. In this paper...

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Main Authors: O'Neill, George C., Barratt, Eleanor L., Hunt, Benjamin A. E., Tewarie, Prejaas K., Brookes, Matthew Jon
Format: Article
Published: IOP 2015
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Online Access:https://eprints.nottingham.ac.uk/31176/
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author O'Neill, George C.
Barratt, Eleanor L.
Hunt, Benjamin A. E.
Tewarie, Prejaas K.
Brookes, Matthew Jon
author_facet O'Neill, George C.
Barratt, Eleanor L.
Hunt, Benjamin A. E.
Tewarie, Prejaas K.
Brookes, Matthew Jon
author_sort O'Neill, George C.
building Nottingham Research Data Repository
collection Online Access
description The human brain can be divided into multiple areas, each responsible for different aspects of behaviour. Healthy brain function relies upon efficient connectivity between these areas and, in recent years, neuroimaging has been revolutionised by an ability to estimate this connectivity. In this paper we discuss measurement of network connectivity using magnetoencephalography (MEG), a technique capable of imaging electrophysiological brain activity with good (~5mm) spatial resolution and excellent (~1ms) temporal resolution. The rich information content of MEG facilitates many disparate measures of connectivity between spatially separate regions and in this paper we discuss a single metric known as power envelope correlation. We review in detail the methodology required to measure power envelope correlation including i) projection of MEG data into source space, ii) removing confounds introduced by the MEG inverse problem and iii) estimation of connectivity itself. In this way, we aim to provide researchers with a description of the key steps required to assess envelope based functional networks, which are thought to represent an intrinsic mode of coupling in the human brain. We highlight the principal findings of the techniques discussed, and furthermore, we show evidence that this method can probe how the brain forms and dissolves multiple transient networks on a rapid timescale in order to support current processing demand. Overall, power envelope correlation offers a unique and verifiable means to gain novel insights into network coordination and is proving to be of significant value in elucidating the neural dynamics of the human connectome in health and disease.
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spelling nottingham-311762020-05-04T17:20:05Z https://eprints.nottingham.ac.uk/31176/ Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods O'Neill, George C. Barratt, Eleanor L. Hunt, Benjamin A. E. Tewarie, Prejaas K. Brookes, Matthew Jon The human brain can be divided into multiple areas, each responsible for different aspects of behaviour. Healthy brain function relies upon efficient connectivity between these areas and, in recent years, neuroimaging has been revolutionised by an ability to estimate this connectivity. In this paper we discuss measurement of network connectivity using magnetoencephalography (MEG), a technique capable of imaging electrophysiological brain activity with good (~5mm) spatial resolution and excellent (~1ms) temporal resolution. The rich information content of MEG facilitates many disparate measures of connectivity between spatially separate regions and in this paper we discuss a single metric known as power envelope correlation. We review in detail the methodology required to measure power envelope correlation including i) projection of MEG data into source space, ii) removing confounds introduced by the MEG inverse problem and iii) estimation of connectivity itself. In this way, we aim to provide researchers with a description of the key steps required to assess envelope based functional networks, which are thought to represent an intrinsic mode of coupling in the human brain. We highlight the principal findings of the techniques discussed, and furthermore, we show evidence that this method can probe how the brain forms and dissolves multiple transient networks on a rapid timescale in order to support current processing demand. Overall, power envelope correlation offers a unique and verifiable means to gain novel insights into network coordination and is proving to be of significant value in elucidating the neural dynamics of the human connectome in health and disease. IOP 2015-10-08 Article PeerReviewed O'Neill, George C., Barratt, Eleanor L., Hunt, Benjamin A. E., Tewarie, Prejaas K. and Brookes, Matthew Jon (2015) Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods. Physics in Medicine and Biology, 60 (21). R271-R295. ISSN 1361-6560 Magnetoencephalography; MEG; functional connectivity; networks; beamformer; Hilbert envelope; leakage; electrophysiology http://iopscience.iop.org/article/10.1088/0031-9155/60/21/R271/meta doi:10.1088/0031-9155/60/21/R271 doi:10.1088/0031-9155/60/21/R271
spellingShingle Magnetoencephalography; MEG; functional connectivity; networks; beamformer; Hilbert envelope; leakage; electrophysiology
O'Neill, George C.
Barratt, Eleanor L.
Hunt, Benjamin A. E.
Tewarie, Prejaas K.
Brookes, Matthew Jon
Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title_full Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title_fullStr Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title_full_unstemmed Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title_short Measuring electrophysiological connectivity by power envelope correlation: a technical review on MEG methods
title_sort measuring electrophysiological connectivity by power envelope correlation: a technical review on meg methods
topic Magnetoencephalography; MEG; functional connectivity; networks; beamformer; Hilbert envelope; leakage; electrophysiology
url https://eprints.nottingham.ac.uk/31176/
https://eprints.nottingham.ac.uk/31176/
https://eprints.nottingham.ac.uk/31176/