Abstract
The default-mode network (DMN) and its principal core hubs in the posterior midline cortices (PMC), i.e., the precuneus and the posterior cingulate cortex, play a critical role in the human brain structural and functional architecture. Because of their centrality, they are affected by a wide spectrum of brain disorders, e.g., Alzheimer's disease. Non-invasive electrophysiological techniques such as magnetoencephalography (MEG) are crucial to the investigation of the neurophysiology of the DMN and its alteration by brain disorders. However, MEG studies relying on band-limited power envelope correlation diverge in their ability to identify the PMC as a part of the DMN in healthy subjects at rest. Since these works were based on different MEG recording systems and different source reconstruction pipelines, we compared DMN functional connectivity estimated with two distinct MEG systems (Elekta, now MEGIN, and CTF) and two widely used reconstruction algorithms (Minimum Norm Estimation and linearly constrained minimum variance Beamformer). Our results identified the reconstruction method as the critical factor influencing PMC functional connectivity, which was significantly dampened by the Beamformer. On this basis, we recommend that future electrophysiological studies on the DMN should rely on Minimum Norm Estimation (or close variants) rather than on the classical Beamformer. Crucially, based on analytic knowledge about these two reconstruction algorithms, we demonstrated with simulations that this empirical observation could be explained by the existence of a spontaneous linear, approximately zero-lag synchronization structure between areas of the DMN or among multiple sources within the PMC. This finding highlights a novel property of the neural dynamics and functional architecture of a core human brain network at rest.
Original language | English |
---|---|
Pages (from-to) | 221-230 |
Number of pages | 10 |
Journal | NeuroImage |
Volume | 200 |
DOIs | |
Publication status | Published - 15 Oct 2019 |
Bibliographical note
Funding Information:M.S. was supported by a research grant by the Wiener-Anspach Foundation (Brussels, Belgium and Oxford, UK) and is supported by the Research Convention “Marc Errens” of the Fonds Erasme (Brussels, Belgium) . X.D.T. is Post-doctorate Clinical Master Specialist at the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Brussels, Belgium) . J.V.S. was supported by a FWO ( 12I1817N , Brussels, Belgium). This research project was supported by research grants from the Wiener-Anspach Foundation (Brussels, Belgium and Oxford, UK) and by the Fonds Erasme (Research Convention “Marc Errens”, Brussels, Belgium) . The MEG project at the CUB – Hôpital Erasme is financially supported by the Fonds Erasme (Research Convention “Les Voies du Savoir”, Brussels, Belgium) .
Funding Information:
M.S. was supported by a research grant by the Wiener-Anspach Foundation (Brussels, Belgium and Oxford, UK) and is supported by the Research Convention “Marc Errens” of the Fonds Erasme (Brussels, Belgium). X.D.T. is Post-doctorate Clinical Master Specialist at the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Brussels, Belgium). J.V.S. was supported by a FWO (12I1817N, Brussels, Belgium). This research project was supported by research grants from the Wiener-Anspach Foundation (Brussels, Belgium and Oxford, UK) and by the Fonds Erasme (Research Convention “Marc Errens”, Brussels, Belgium). The MEG project at the CUB – Hôpital Erasme is financially supported by the Fonds Erasme (Research Convention “Les Voies du Savoir”, Brussels, Belgium).
Publisher Copyright:
© 2019
Keywords
- Functional connectivity
- Linear synchronization
- Magnetoencephalography
- Resting state
- Source reconstruction
ASJC Scopus subject areas
- Neurology
- Cognitive Neuroscience