On-scalp magnetocorticography with optically pumped magnetometers: Simulated performance in resolving simultaneous
Allison C Nugent1, Amaia Benitez Andonegui1, Tom Holroyd1
1Magnetoencephlography Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Neuroimage. Reports
|June 13, 2022
Summary
Optically pumped magnetometers offer a non-invasive alternative to invasive electrocorticography for mapping brain activity. This research demonstrates their potential for high-resolution source localization, advancing neuroscience research.
Area of Science:
- Neuroscience
- Biophysics
- Biomedical Engineering
Background:
- Invasive electrocorticography (ECoG) is the gold standard for high-resolution cortical mapping but carries significant risks, limiting its use.
- ECoG studies, often in epilepsy patients, have limitations in generalizability and sensor placement.
- Understanding simultaneous independent neuronal assemblies is crucial for cognitive process research.
Purpose of the Study:
- To explore optically pumped magnetometers (OPMs) as a non-invasive alternative to ECoG, termed magnetocorticography.
- To evaluate the capability of a theoretical 56-channel dense OPM array in resolving simultaneous independent neuronal sources.
- To compare the performance of OPMs against SQUID devices and other OPM configurations.
Main Methods:
- Simulations of a theoretical 56-channel dense OPM array.
- Assessment of error sources including sensor calibration and positioning.
- Investigation of geometrical and anatomical factors influencing array performance.
Main Results:
- High-density, on-scalp OPM magnetoencephalography (MEG) devices show potential for unprecedented non-invasive resolution.
- The theoretical OPM array demonstrated capability in resolving simultaneous independent sources.
- Performance was evaluated against SQUID devices and varying OPM inter-sensor spacings.
Conclusions:
- OPMs offer a promising non-invasive approach for high-resolution brain activity mapping.
- Magnetocorticography could overcome limitations of invasive ECoG.
- Further development of OPM-based MEG systems could significantly advance non-invasive neuroscience research.
