skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Single-trial classification of evoked responses to auditory tones using OPM- and SQUID-MEG

Journal Article · · Journal of Neural Engineering

Abstract Objective. Optically pumped magnetometers (OPMs) are emerging as a near-room-temperature alternative to superconducting quantum interference devices (SQUIDs) for magnetoencephalography (MEG). In contrast to SQUIDs, OPMs can be placed in a close proximity to subject’s scalp potentially increasing the signal-to-noise ratio and spatial resolution of MEG. However, experimental demonstrations of these suggested benefits are still scarce. Here, to compare a 24-channel OPM-MEG system to a commercial whole-head SQUID system in a data-driven way, we quantified their performance in classifying single-trial evoked responses. Approach. We measured evoked responses to three auditory tones in six participants using both OPM- and SQUID-MEG systems. We performed pairwise temporal classification of the single-trial responses with linear discriminant analysis as well as multiclass classification with both EEGNet convolutional neural network and xDAWN decoding. Main results. OPMs provided higher classification accuracies than SQUIDs having a similar coverage of the left hemisphere of the participant. However, the SQUID sensors covering the whole helmet had classification scores larger than those of OPMs for two of the tone pairs, demonstrating the benefits of a whole-head measurement. Significance. The results demonstrate that the current OPM-MEG system provides high-quality data about the brain with room for improvement for high bandwidth non-invasive brain–computer interfacing.

Sponsoring Organization:
USDOE
Grant/Contract Number:
U01EB028656; R01EB013302
OSTI ID:
2007979
Alternate ID(s):
OSTI ID: 2005010
Journal Information:
Journal of Neural Engineering, Journal Name: Journal of Neural Engineering Vol. 20 Journal Issue: 5; ISSN 1741-2560
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United Kingdom
Language:
English

References (46)

Non-Invasive Functional-Brain-Imaging with an OPM-based Magnetoencephalography System journal January 2020
On the interpretation of weight vectors of linear models in multivariate neuroimaging journal February 2014
Four-channel optically pumped atomic magnetometer for magnetoencephalography journal January 2016
Rhythmic pulsing: linking ongoing brain activity with evoked responses journal January 2010
Microfabricated optically-pumped magnetometers for imaging applications conference March 2023
Optical magnetometry journal April 2007
MNE software for processing MEG and EEG data journal February 2014
Transforming and comparing data between standard SQUID and OPM-MEG systems journal January 2022
Kernel Flux: a whole-head 432-magnetometer optically-pumped magnetoencephalography (OP-MEG) system for brain activity imaging during natural human experiences conference March 2021
The development of auditory evoked dipole source activity from childhood to adulthood journal December 2000
A minimum assumption approach to MEG sensor array design journal August 2023
Magnetoencephalography—theory, instrumentation, and applications to noninvasive studies of the working human brain journal April 1993
Pragmatic spatial sampling for wearable MEG arrays journal December 2020
Optimising the sensing volume of OPM sensors for MEG source reconstruction journal December 2022
Multi-channel whole-head OPM-MEG: Helmet design and a comparison with a conventional system journal October 2020
Triaxial detection of the neuromagnetic field using optically-pumped magnetometry: feasibility and application in children journal May 2022
On-scalp magnetocorticography with optically pumped magnetometers: Simulated performance in resolving simultaneous sources journal June 2022
A compact, high performance atomic magnetometer for biomedical applications journal November 2013
Cross-Axis projection error in optically pumped magnetometers and its implication for magnetoencephalography systems journal February 2022
Cognitive neuroscience using wearable magnetometer arrays: Non-invasive assessment of language function journal November 2018
Detection of the 40 Hz auditory steady-state response with optically pumped magnetometers journal October 2022
A tool for functional brain imaging with lifespan compliance journal November 2019
Multiclass Brain–Computer Interface Classification by Riemannian Geometry journal April 2012
Spatiotemporal signal space separation method for rejecting nearby interference in MEG measurements journal March 2006
Measuring MEG closer to the brain: Performance of on-scalp sensor arrays journal February 2017
Evolution of MEG: A first MEG‐feasible fluxgate magnetometer journal July 2021
A 20-channel magnetoencephalography system based on optically pumped magnetometers journal November 2017
Comparison Between Conventional SQUID Based and Novel OPM Based Measuring Systems in MEG book November 2020
Optimal design of on‐scalp electromagnetic sensor arrays for brain source localisation journal July 2021
Non-invasive measurements of ictal and interictal epileptiform activity using optically pumped magnetometers journal March 2023
Potential of on‐scalp MEG: Robust detection of human visual gamma‐band responses journal October 2019
An integrated full-head OPM-MEG system based on 128 zero-field sensors journal June 2023
On the Potential of a New Generation of Magnetometers for MEG: A Beamformer Simulation Study journal August 2016
Independent component analysis: algorithms and applications journal June 2000
Imaging somatosensory cortex responses measured by OPM-MEG: Variational free energy-based spatial smoothing estimation approach journal February 2022
Theoretical advantages of a triaxial optically pumped magnetometer magnetoencephalography system journal August 2021
On-scalp MEG SQUIDs are sensitive to early somatosensory activity unseen by conventional MEG journal November 2020
A New Generation of OPM for High Dynamic and Large Bandwidth MEG: The 4He OPMs—First Applications in Healthy Volunteers journal March 2023
xDAWN Algorithm to Enhance Evoked Potentials: Application to Brain–Computer Interface journal August 2009
Controlling the False Discovery Rate: A Practical and Powerful Approach to Multiple Testing journal January 1995
EEGNet: a compact convolutional neural network for EEG-based brain–computer interfaces journal July 2018
Moving magnetoencephalography towards real-world applications with a wearable system journal March 2018
Centrality of Social Interaction in Human Brain Function journal October 2015
Spatial sampling of MEG and EEG based on generalized spatial-frequency analysis and optimal design journal December 2021
Performance Analysis of Optically Pumped 4He Magnetometers vs. Conventional SQUIDs: From Adult to Infant Head Models journal April 2022
On-scalp MEG system utilizing an actively shielded array of optically-pumped magnetometers journal July 2019

Similar Records

Non-Invasive Functional-Brain-Imaging with an OPM-based Magnetoencephalography System
Journal Article · Fri Jan 24 00:00:00 EST 2020 · PLoS ONE · OSTI ID:2007979

A 20-channel magnetoencephalography system based on optically pumped magnetometers
Journal Article · Mon Oct 16 00:00:00 EDT 2017 · Physics in Medicine and Biology · OSTI ID:2007979

Localization precision of the superconducting imaging-surface MEG system
Conference · Mon Jan 01 00:00:00 EST 2001 · OSTI ID:2007979

Related Subjects