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

AbstractElectrophysiological 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 inter-sensor spacing.

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Atypical resting-state gamma band trajectory in adult attention deficit/hyperactivity disorder

Journal of Neural Transmission ◽

10.1007/s00702-021-02368-2 ◽

2021 ◽

Author(s):

László Tombor ◽

Brigitta Kakuszi ◽

Szilvia Papp ◽

János Réthelyi ◽

István Bitter ◽

...

Keyword(s):

Attention Deficit Hyperactivity Disorder ◽

Attention Deficit ◽

Adult Adhd ◽

Neurodevelopmental Disorder ◽

Gamma Band ◽

Gamma Activity ◽

Hyperactivity Disorder ◽

Gamma Power ◽

Gamma Band Activity ◽

Band Activity

AbstractDecreased gamma activity has been reported both in children and adults with attention deficit/hyperactivity disorder (ADHD). However, while ADHD is a lifelong neurodevelopmental disorder, our insight into the associations of spontaneous gamma band activity with age is limited, especially in adults. Therefore, we conducted an explorative study to investigate trajectories of resting gamma activity in adult ADHD patients (N = 42) versus matched healthy controls (N = 59). We investigated the relationship of resting gamma activity (30–48 Hz) with age in four right hemispheric electrode clusters where diminished gamma power in ADHD had previously been demonstrated by our group. We found significant non-linear association between resting gamma power and age in the lower frequency gamma1 range (30–39 Hz) in ADHD as compared to controls in all investigated locations. Resting gamma1 increased with age and was significantly lower in ADHD than in control subjects from early adulthood. We found no significant association between gamma activity and age in the gamma2 range (39–48 Hz). Alterations of gamma band activity might reflect altered cortical network functioning in adult ADHD relative to controls. Our results reveal that abnormal gamma power is present at all ages, highlighting the lifelong nature of ADHD. Nonetheless, longitudinal studies are needed to confirm our results.

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Genetic risk for schizophrenia is associated with altered visually-induced gamma band activity: evidence from a population sample stratified polygenic risk

Translational Psychiatry ◽

10.1038/s41398-021-01678-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

S. I. Dimitriadis ◽

G. Perry ◽

S. F. Foley ◽

K. E. Tansey ◽

D. K. Jones ◽

...

Keyword(s):

Genetic Risk ◽

Genetic Risk Score ◽

Population Sample ◽

Gamma Band ◽

Synaptic Function ◽

Gamma Activity ◽

Group Differences ◽

Neuropsychiatric Diseases ◽

Gamma Band Activity ◽

Band Activity

AbstractGamma oscillations (30–90 Hz) have been proposed as a signature of cortical visual information processing, particularly the balance between excitation and inhibition, and as a biomarker of neuropsychiatric diseases. Magnetoencephalography (MEG) provides highly reliable visual-induced gamma oscillation estimates, both at sensor and source level. Recent studies have reported a deficit of visual gamma activity in schizophrenia patients, in medication naive subjects, and high-risk clinical participants, but the genetic contribution to such a deficit has remained unresolved. Here, for the first time, we use a genetic risk score approach to assess the relationship between genetic risk for schizophrenia and visual gamma activity in a population-based sample drawn from a birth cohort. We compared visual gamma activity in a group (N = 104) with a high genetic risk profile score for schizophrenia (SCZ-PRS) to a group with low SCZ-PRS (N = 99). Source-reconstructed V1 activity was extracted using beamformer analysis applied to MEG recordings using individual MRI scans. No group differences were found in the induced gamma peak amplitude or peak frequency. However, a non-parametric statistical contrast of the response spectrum revealed more robust group differences in the amplitude of high-beta/gamma power across the frequency range, suggesting that overall spectral shape carries important biological information beyond the individual frequency peak. Our findings show that changes in gamma band activity correlate with liability to schizophrenia and suggest that the index changes to synaptic function and neuronal firing patterns that are of pathophysiological relevance rather than consequences of the disorder.

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Stimulus-induced Gamma Power Predicts the Amplitude of the Subsequent Visual Evoked Response

10.1101/388587 ◽

2018 ◽

Author(s):

Mats W.J. van Es ◽

Jan-Mathijs Schoffelen

Keyword(s):

Gamma Band ◽

Evoked Response ◽

Pattern Reversal ◽

Visual Evoked Response ◽

Cortical Areas ◽

Gamma Power ◽

Visual Cortical ◽

Gamma Band Activity ◽

Band Activity ◽

Visual Evoked

AbstractThe efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesizedthat the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses.Significance statementGamma-band activity has been associated with many cognitive functions and improved behavioral performance. For example, high amplitude gamma-band activity in visual cortical areas before a go cue leads to faster reaction times. However, it remains unclear through which neural mechanism(s) gamma-band activity eventually affects behavior. We tested whether the strength of induced gamma-band activity affects evoked activity elicited by a subsequent visual stimulus. We found enhanced amplitudes of early visual evoked activity, and faster responses with higher gamma power. This suggests that gamma-band activity affects the neuronal gain to new sensory input, and thus these results bridge the gap between gamma power and behavior, and support the putative role of gamma-band activity in the efficiency of cortical processing.

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Gamma band activity in an auditory oddball paradigm studied with the wavelet transform

Clinical Neurophysiology ◽

10.1016/s1388-2457(01)00557-0 ◽

2001 ◽

Vol 112 (7) ◽

pp. 1219-1228 ◽

Cited By ~ 67

Author(s):

I.G Gurtubay ◽

M Alegre ◽

A Labarga ◽

A Malanda ◽

J Iriarte ◽

...

Keyword(s):

Wavelet Transform ◽

Gamma Band ◽

Oddball Paradigm ◽

Auditory Oddball ◽

Gamma Band Activity ◽

Auditory Oddball Paradigm ◽

Band Activity

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Increased Thalamic Gamma Band Activity Correlates with Symptom Relief following Deep Brain Stimulation in Humans with Tourette’s Syndrome

PLoS ONE ◽

10.1371/journal.pone.0044215 ◽

2012 ◽

Vol 7 (9) ◽

pp. e44215 ◽

Cited By ~ 58

Author(s):

Nicholas Maling ◽

Rowshanak Hashemiyoon ◽

Kelly D. Foote ◽

Michael S. Okun ◽

Justin C. Sanchez

Keyword(s):

Deep Brain Stimulation ◽

Brain Stimulation ◽

Symptom Relief ◽

Gamma Band ◽

Tourette's Syndrome ◽

Tourette’S Syndrome ◽

Gamma Band Activity ◽

Band Activity ◽

Deep Brain

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Gamma band activity and its synchronization reflect the dysfunctional emotional processing in alexithymic persons

Psychophysiology ◽

10.1111/j.1469-8986.2006.00461.x ◽

2006 ◽

Vol 43 (6) ◽

pp. 533-540 ◽

Cited By ~ 28

Author(s):

Atsushi Matsumoto ◽

Yoko Ichikawa ◽

Noriaki Kanayama ◽

Hideki Ohira ◽

Tetsuya Iidaka

Keyword(s):

Emotional Processing ◽

Gamma Band ◽

Gamma Band Activity ◽

Band Activity

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FEF-Controlled Alpha Delay Activity Precedes Stimulus-Induced Gamma-Band Activity in Visual Cortex

Journal of Neuroscience ◽

10.1523/jneurosci.3015-16.2017 ◽

2017 ◽

Vol 37 (15) ◽

pp. 4117-4127 ◽

Cited By ~ 44

Author(s):

Tzvetan Popov ◽

Sabine Kastner ◽

Ole Jensen

Keyword(s):

Visual Cortex ◽

Gamma Band ◽

Gamma Band Activity ◽

Band Activity

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Increased EEG gamma band activity in Alzheimer’s disease and mild cognitive impairment

Journal of Neural Transmission ◽

10.1007/s00702-008-0083-y ◽

2008 ◽

Vol 115 (9) ◽

pp. 1301-1311 ◽

Cited By ~ 59

Author(s):

J. A. van Deursen ◽

E. F. P. M. Vuurman ◽

F. R. J. Verhey ◽

V. H. J. M. van Kranen-Mastenbroek ◽

W. J. Riedel

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Gamma Band ◽

Gamma Band Activity ◽

Band Activity

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Interictal Abnormalities of Gamma Band Activity in Visual Evoked Responses in Migraine: An Indication of Thalamocortical Dysrhythmia?

Cephalalgia ◽

10.1111/j.1468-2982.2007.01466.x ◽

2007 ◽

Vol 27 (12) ◽

pp. 1360-1367 ◽

Cited By ~ 84

Author(s):

G Coppola ◽

A Ambrosini ◽

L Di Clemente ◽

D Magis ◽

A Fumal ◽

...

Keyword(s):

High Frequency ◽

Gamma Band ◽

Pattern Reversal ◽

Evoked Responses ◽

Visual Evoked Responses ◽

High Frequency Oscillations ◽

Thalamocortical Dysrhythmia ◽

Gamma Band Activity ◽

Band Activity ◽

Visual Evoked

Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20–35 Hz) assumed to be generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in six successive blocks of 100 averaged pattern reversal (PR)-VEPs in healthy volunteers and interictally in migraine with (MA) or without aura patients. Amplitude of the two early GBO components in the first PR-VEP block was significantly increased in MA patients. There was a significant habituation deficit of the late GBO peaks in migraineurs. The increased amplitude of early GBOs could be related to the increased interictal visual discomfort reported by patients. We hypothesize that the hypo-functioning serotonergic pathways may cause, in line with the thalamocortical dysrhythmia theory, a functional disconnection of the thalamus leading to decreased intracortical lateral inhibition, which can induce dishabituation.

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