Potential of on-scalp MEG: Robust detection of human visual gamma-band responses

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@article{bb8388c165ba4bf2b98f883c0b20c945,
title = "Potential of on-scalp MEG: Robust detection of human visual gamma-band responses",
abstract = "Electrophysiological signals recorded intracranially show rich frequency content spanning from near-DC to hundreds of hertz. Noninvasive electromagnetic signals measured with electroencephalography (EEG) or magnetoencephalography (MEG) typically contain less signal power in high frequencies than invasive recordings. Particularly, noninvasive detection of gamma-band activity (>30 Hz) is challenging since coherently active source areas are small at such frequencies and the available imaging methods have limited spatial resolution. Compared to EEG and conventional SQUID-based MEG, on-scalp MEG should provide substantially improved spatial resolution, making it an attractive method for detecting gamma-band activity. Using an on-scalp array comprised of eight optically pumped magnetometers (OPMs) and a conventional whole-head SQUID array, we measured responses to a dynamic visual stimulus known to elicit strong gamma-band responses. OPMs had substantially higher signal power than SQUIDs, and had a slightly larger relative gamma-power increase over the baseline. With only eight OPMs, we could obtain gamma-activity source estimates comparable to those of SQUIDs at the group level. Our results show the feasibility of OPMs to measure gamma-band activity. To further facilitate the noninvasive detection of gamma-band activity, the on-scalp OPM arrays should be optimized with respect to sensor noise, the number of sensors and intersensor spacing.",
keywords = "gamma band, magnetoencephalography, optically pumped magnetometer, visual system, HIGH-FREQUENCY OSCILLATIONS, LOCAL-FIELD POTENTIALS, SOMATOSENSORY CORTEX, WORKING-MEMORY, EEG, SYNCHRONIZATION, MAGNETOENCEPHALOGRAPHY, DESYNCHRONIZATION, DYNAMICS, RHYTHMS",
author = "Joonas Iivanainen and Rasmus Zetter and Lauri Parkkonen",
note = "| openaire: EC/H2020/678578/EU//HRMEG",
year = "2019",
month = "10",
day = "1",
doi = "10.1002/hbm.24795",
language = "English",
journal = "Human Brain Mapping",
issn = "1065-9471",
publisher = "Wiley",

}

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TY - JOUR

T1 - Potential of on-scalp MEG

T2 - Robust detection of human visual gamma-band responses

AU - Iivanainen, Joonas

AU - Zetter, Rasmus

AU - Parkkonen, Lauri

N1 - | openaire: EC/H2020/678578/EU//HRMEG

PY - 2019/10/1

Y1 - 2019/10/1

N2 - Electrophysiological signals recorded intracranially show rich frequency content spanning from near-DC to hundreds of hertz. Noninvasive electromagnetic signals measured with electroencephalography (EEG) or magnetoencephalography (MEG) typically contain less signal power in high frequencies than invasive recordings. Particularly, noninvasive detection of gamma-band activity (>30 Hz) is challenging since coherently active source areas are small at such frequencies and the available imaging methods have limited spatial resolution. Compared to EEG and conventional SQUID-based MEG, on-scalp MEG should provide substantially improved spatial resolution, making it an attractive method for detecting gamma-band activity. Using an on-scalp array comprised of eight optically pumped magnetometers (OPMs) and a conventional whole-head SQUID array, we measured responses to a dynamic visual stimulus known to elicit strong gamma-band responses. OPMs had substantially higher signal power than SQUIDs, and had a slightly larger relative gamma-power increase over the baseline. With only eight OPMs, we could obtain gamma-activity source estimates comparable to those of SQUIDs at the group level. Our results show the feasibility of OPMs to measure gamma-band activity. To further facilitate the noninvasive detection of gamma-band activity, the on-scalp OPM arrays should be optimized with respect to sensor noise, the number of sensors and intersensor spacing.

AB - Electrophysiological signals recorded intracranially show rich frequency content spanning from near-DC to hundreds of hertz. Noninvasive electromagnetic signals measured with electroencephalography (EEG) or magnetoencephalography (MEG) typically contain less signal power in high frequencies than invasive recordings. Particularly, noninvasive detection of gamma-band activity (>30 Hz) is challenging since coherently active source areas are small at such frequencies and the available imaging methods have limited spatial resolution. Compared to EEG and conventional SQUID-based MEG, on-scalp MEG should provide substantially improved spatial resolution, making it an attractive method for detecting gamma-band activity. Using an on-scalp array comprised of eight optically pumped magnetometers (OPMs) and a conventional whole-head SQUID array, we measured responses to a dynamic visual stimulus known to elicit strong gamma-band responses. OPMs had substantially higher signal power than SQUIDs, and had a slightly larger relative gamma-power increase over the baseline. With only eight OPMs, we could obtain gamma-activity source estimates comparable to those of SQUIDs at the group level. Our results show the feasibility of OPMs to measure gamma-band activity. To further facilitate the noninvasive detection of gamma-band activity, the on-scalp OPM arrays should be optimized with respect to sensor noise, the number of sensors and intersensor spacing.

KW - gamma band

KW - magnetoencephalography

KW - optically pumped magnetometer

KW - visual system

KW - HIGH-FREQUENCY OSCILLATIONS

KW - LOCAL-FIELD POTENTIALS

KW - SOMATOSENSORY CORTEX

KW - WORKING-MEMORY

KW - EEG

KW - SYNCHRONIZATION

KW - MAGNETOENCEPHALOGRAPHY

KW - DESYNCHRONIZATION

KW - DYNAMICS

KW - RHYTHMS

U2 - 10.1002/hbm.24795

DO - 10.1002/hbm.24795

M3 - Article

JO - Human Brain Mapping

JF - Human Brain Mapping

SN - 1065-9471

ER -

ID: 37836575