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Magnetoencephalography for brain electrophysiology and imaging

Abstract

We review the aspects that uniquely characterize magnetoencephalography (MEG) among the techniques available to explore and resolve brain function and dysfunction. While emphasizing its specific strengths in terms of millisecond source imaging, we also identify and discuss current practical challenges, in particular in signal extraction and interpretation. We also take issue with some perceived disadvantages of MEG, including the misconception that the technique is redundant with electroencephalography. Overall, MEG contributes uniquely to our deeper comprehension of both regional and large-scale brain dynamics: from the functions of neural oscillations and the nature of event-related brain activation, to the mechanisms of functional connectivity between regions and the emergence of modes of network communication in brain systems. We expect MEG to play an increasing and pivotal role in the elucidation of these grand mechanistic principles of cognitive, systems and clinical neuroscience.

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Figure 1: Cellular origins of MEG signals.
Figure 2: An example comparing MEG and EEG.
Figure 3: Major steps required and possibilities offered by MEG analytics.
Figure 4: Toward big-data MEG.
Figure 5: Frequency-dependent expressions of inter-regional connectivity.
Figure 6: A possible mechanistic framework of polyrhythmic brain activity.
Figure 7: Snapshots of MEG science.

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Acknowledgements

S.B. is supported by a Discovery Grant from the National Science and Engineering Research Council of Canada, the NIH (2R01EB009048-05) and a Platform Support Grant from the Brain Canada Foundation.

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Baillet, S. Magnetoencephalography for brain electrophysiology and imaging. Nat Neurosci 20, 327–339 (2017). https://doi.org/10.1038/nn.4504

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