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Hartwig R. Siebner - One of the best experts on this subject based on the ideXlab platform.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    Brain Stimulation, 2021
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Abstract Background Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude. Conclusion The relationship between cortical oscillatory activity and cortical excitability is complex and minor differences in the methodological choices may critically affect sensitivity.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    bioRxiv, 2020
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Background: Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives: To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods: 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results: Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm.
    Brain stimulation, 2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270° of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm
    2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270 degrees of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase. Highlights Phase-triggered TMS at four distinct phases of the ongoing Mu-oscillations is technically feasible in non-preselected young volunteers Targeting the ongoing Mu-activity did not reveal consistent modulatory effect of Mu-phase on corticospinal excitability in a non-preselected group Mixed-effects analysis revealed a weak but significant effect of pre-stiMulus Mu-power and ISI on corticospinal excitability

Anke Ninija Karabanov - One of the best experts on this subject based on the ideXlab platform.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    Brain Stimulation, 2021
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Abstract Background Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude. Conclusion The relationship between cortical oscillatory activity and cortical excitability is complex and minor differences in the methodological choices may critically affect sensitivity.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    bioRxiv, 2020
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Background: Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives: To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods: 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results: Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm.
    Brain stimulation, 2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270° of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm
    2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270 degrees of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase. Highlights Phase-triggered TMS at four distinct phases of the ongoing Mu-oscillations is technically feasible in non-preselected young volunteers Targeting the ongoing Mu-activity did not reveal consistent modulatory effect of Mu-phase on corticospinal excitability in a non-preselected group Mixed-effects analysis revealed a weak but significant effect of pre-stiMulus Mu-power and ISI on corticospinal excitability

Nathan A. Fox - One of the best experts on this subject based on the ideXlab platform.

  • intranasal oxytocin enhances eeg Mu Rhythm desynchronization during execution and observation of social action an exploratory study
    Psychoneuroendocrinology, 2020
    Co-Authors: Fabrizia Festante, Pier Francesco Ferrari, Samuel G Thorpe, Robert W Buchanan, Nathan A. Fox
    Abstract:

    Abstract Intranasal administration of oxytocin (OT) has been found to facilitate prosocial behaviors, emotion recognition and cooperation between individuals. Recent electroencephalography (EEG) investigations have reported enhanced Mu Rhythm (alpha: 8–13 Hz; beta: 15–25 Hz) desynchronization during the observation of biological motion and stiMuli probing social synchrony after the administration of intranasal OT. This hormone may therefore target a network of cortical circuits involved in higher cognitive functions, including the mirror neuron system (MNS). Here, in a double-blind, placebo-controlled, between-subjects exploratory study, we investigated whether intranasal OT modulates the cortical activity from sensorimotor areas during the observation and the execution of social and non-social grasping actions. Participants underwent EEG testing after receiving a single dose (24 IU) of either intranasal OT or placebo. Results revealed an enhancement of alpha - but not beta - desynchronization during observation and execution of social grasps, especially over central and parietal electrodes, in participants who received OT (OT group). No differences between the social and non-social condition were found in the control group (CTRL group). Moreover, we found a significant difference over the cortical central-parietal region between the OT and CTRL group only within the social condition. These results suggest a possible action of intranasal OT on sensorimotor circuits involved in social perception and action understanding, which might contribute to facilitate the prosocial effects typically reported by behavioral studies.

  • Mu Rhythm desynchronization is specific to action execution and observation evidence from time frequency and connectivity analysis
    NeuroImage, 2019
    Co-Authors: Ranjan Debnath, Kathryn H. Yoo, Virginia C Salo, George A Buzzell, Nathan A. Fox
    Abstract:

    Abstract Mu desynchronization is the attenuation of EEG power in the alpha frequency range recorded over central scalp locations thought to reflect motor cortex activation. Mu desynchronization during observation of an action is believed to reflect mirroring system activation in humans. However, this notion has recently been questioned because, among other reasons, the potential contamination of Mu Rhythm and occipital alpha activity induced by attention processes following presentation of visual stiMuli in observation conditions. This study examined the validity of Mu desynchronization as a measure of mirroring system activation in infants and further investigated the pattern of functional connectivity between the central and occipital regions during execution and observation of movement. EEG was recorded while 46 9-month-old infants executed grasping actions and observed an experimenter grasping. Current source density (CSD) was applied to EEG data and, time-frequency and connectivity analyses were performed in CSD transformed data. Mu desynchronization was evident over central regions during both execution and observation of movements. Independent alpha desynchronization over occipital region was also present in both conditions. The connectivity analyses revealed that central-occipital areas were functionally more connected compared to other areas of the brain during observation of movements. Collectively, the results demonstrate the validity of Mu desynchronization as an index of infant mirroring system activity and support the proposal of a functional connection between distinct mirroring and attention processes during observation of action.

  • assessing human mirror activity with eeg Mu Rhythm a meta analysis
    Psychological Bulletin, 2016
    Co-Authors: Nathan A. Fox, Erin N. Cannon, Kathryn H. Yoo, Ross E. Vanderwert, Pier Francesco Ferrari, Marian J Bakermanskranenburg, Lindsay C Bowman, Marinus H Van Ijzendoorn
    Abstract:

    A fundamental issue in cognitive neuroscience is how the brain encodes others' actions and intentions. In recent years, a potential advance in our knowledge on this issue is the discovery of mirror neurons in the motor cortex of the nonhuman primate. These neurons fire to both execution and observation of specific types of actions. Researchers use this evidence to fuel investigations of a human mirror system, suggesting a common neural code for perceptual and motor processes. Among the methods used for inferring mirror system activity in humans are changes in a particular frequency band in the electroencephalogram (EEG) called the Mu Rhythm. Mu frequency appears to decrease in amplitude (reflecting cortical activity) during both action execution and action observation. The current meta-analysis reviewed 85 studies (1,707 participants) of Mu that infer human mirror system activity. Results demonstrated significant effect sizes for Mu during execution (Cohen's d = 0.46, N = 701) as well as observation of action (Cohen's d = 0.31, N = 1,508), confirming a mirroring property in the EEG. A number of moderators were examined to determine the specificity of these effects. We frame these meta-analytic findings within the current discussion about the development and functions of a human mirror system, and conclude that changes in EEG Mu activity provide a valid means for the study of human neural mirroring. Suggestions for improving the experimental and methodological approaches in using Mu to study the human mirror system are offered.

  • The Infant EEG Mu Rhythm: Methodological Considerations and Best Practices.
    Developmental review : DR, 2014
    Co-Authors: Kimberly Cuevas, Erin N. Cannon, Kathryn H. Yoo, Nathan A. Fox
    Abstract:

    The EEG Mu Rhythm, recorded from scalp regions overlying the sensorimotor cortex, appears to exhibit mirroring properties: It is reactive when performing an action and when observing another perform the same action. Recently, there has been an exponential increase in developmental Mu Rhythm research, partially due to the Mu Rhythm’s potential role in our understanding of others’ actions as well as a variety of other social and cognitive processes (e.g., imitation, theory of mind, language). Unfortunately, various methodological issues impede integrating these findings into a comprehensive theory of Mu Rhythm development. The present manuscript provides a review of the infant Mu Rhythm literature while focusing on current methodological problems that impede between study comparisons. By highlighting these issues and providing an in depth description and analysis we aim to heighten awareness and propose guidelines (when possible) that will promote rigorous infant Mu Rhythm research and facilitate between study comparisons. This paper is intended as a resource for developmental scientists, regardless of EEG expertise.

  • Action experience, more than observation, influences Mu Rhythm desynchronization
    PLoS ONE, 2014
    Co-Authors: Erin N. Cannon, Kathryn H. Yoo, Ross E. Vanderwert, Pier F. Ferrari, Amanda L Woodward, Nathan A. Fox
    Abstract:

    Since the discovery of mirror neurons in premotor and parietal areas of the macaque monkey, the idea that action and perception may share the same neural code has been of central interest in social, developmental, and cognitive neurosciences. A fundamental question concerns how a putative human mirror neuron system may be tuned to the motor experiences of the individual. The current study tested the hypothesis that prior motor experience modulated the sensorimotor Mu and beta Rhythms. Specifically, we hypothesized that these sensorimotor Rhythms would be more desynchronized after active motor experience compared to passive observation experience. To test our hypothesis, we collected EEG from adult participants during the observation of a relatively novel action: an experimenter used a claw-like tool to pick up a toy. Prior to EEG collection, we trained one group of adults to perform this action with the tool (performers). A second group comprised trained video coders, who only had experience observing the action (observers). Both the performers and the observers had no prior motor and visual experience with the action. A third group of novices was also tested. Performers exhibited the greatest Mu Rhythm desynchronization in the 8-13 Hz band, particularly in the right hemisphere compared to observers and novices. This study is the first to contrast active tool-use experience and observation experience in the Mu Rhythm and to show modulation with relatively shorter amounts of experience than prior mirror neuron expertise studies. These findings are discussed with respect to its broader implication as a neural signature for a mechanism of early social learning.

Kristoffer Hougaard Madsen - One of the best experts on this subject based on the ideXlab platform.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    Brain Stimulation, 2021
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Abstract Background Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude. Conclusion The relationship between cortical oscillatory activity and cortical excitability is complex and minor differences in the methodological choices may critically affect sensitivity.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    bioRxiv, 2020
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Background: Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives: To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods: 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results: Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm.
    Brain stimulation, 2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270° of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm
    2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270 degrees of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase. Highlights Phase-triggered TMS at four distinct phases of the ongoing Mu-oscillations is technically feasible in non-preselected young volunteers Targeting the ongoing Mu-activity did not reveal consistent modulatory effect of Mu-phase on corticospinal excitability in a non-preselected group Mixed-effects analysis revealed a weak but significant effect of pre-stiMulus Mu-power and ISI on corticospinal excitability

Laerke Gebser Krohne - One of the best experts on this subject based on the ideXlab platform.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    Brain Stimulation, 2021
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Abstract Background Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude. Conclusion The relationship between cortical oscillatory activity and cortical excitability is complex and minor differences in the methodological choices may critically affect sensitivity.

  • does pericentral Mu Rhythm power corticomotor excitability a matter of eeg perspective
    bioRxiv, 2020
    Co-Authors: Anke Ninija Karabanov, Kristoffer Hougaard Madsen, Laerke Gebser Krohne, Hartwig R. Siebner
    Abstract:

    Background: Electroencephalography (EEG) and single-pulse transcranial magnetic stiMulation (spTMS) of the primary motor hand area (M1-HAND) have been combined to explore whether the instantaneous expression of pericentral Mu-Rhythm drives fluctuations in corticomotor excitability, but this line of research has yielded diverging results. Objectives: To re-assess the relationship between the Mu-Rhythm power expressed in left pericentral cortex and the amplitude of motor potentials (MEP) evoked with spTMS in left M1-HAND. Methods: 15 non-preselected healthy young participants received spTMS to the motor hot spot of left M1-HAND. Regional expression of Mu-Rhythm was estimated online based on a radial source at motor hotspot and informed the timing of spTMS which was applied either during epochs belonging to the highest or lowest quartile of regionally expressed Mu-power. Using MEP amplitude as dependent variable, we computed a linear mixed-effects model, which included Mu-power and Mu-phase at the time of stiMulation and the inter-stiMulus interval (ISI) as fixed effects and subject as a random effect. Mu-phase was estimated by post-hoc sorting of trials into four discrete phase bins. We performed a follow-up analysis on the same EEG-triggered MEP data set in which we isolated Mu-power at the sensor level using a Laplacian montage centered on the electrode above the M1-HAND. Results: Pericentral Mu-power traced as radial source at motor hot spot did not significantly modulate the MEP, but Mu-power determined by the surface Laplacian did, showing a positive relation between Mu-power and MEP amplitude. In neither case, there was an effect of Mu-phase on MEP amplitude.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm.
    Brain stimulation, 2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270° of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase.

  • No trace of phase: Corticomotor excitability is not tuned by phase of pericentral Mu-Rhythm
    2019
    Co-Authors: Kristoffer Hougaard Madsen, Anke Ninija Karabanov, Laerke Gebser Krohne, Mads Gylling Safeldt, Leo Tomasevic, Hartwig R. Siebner
    Abstract:

    Abstract Background The motor potentials evoked by transcranial magnetic stiMulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral Mu-Rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting Mu-activity based on real-time electroencephalography (EEG) reported an influence of Mu-power and Mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral Mu-activity. Other studies that determined Mu-power or Mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative. Objectives To reassess if cortico-spinal activity is modulated by the Mu-Rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral Mu-Rhythm in 14 non-preselected healthy young participants. Methods TMS was given at 0, 90, 180, and 270 degrees of the Mu-phase. Based on the absence of effects of Mu-phase or Mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included Mu-phase, Mu-power, inter-stiMulus interval (ISIs) as fixed effects, treating the subject factor as a random effect. Results Mixed model analysis revealed a significant effect of Mu-power and ISI, but no effect of Mu-phase and no interactions. MEP amplitude scaled linearly with lower Mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability. Conclusion Our largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with Mu-power and Mu-phase. Highlights Phase-triggered TMS at four distinct phases of the ongoing Mu-oscillations is technically feasible in non-preselected young volunteers Targeting the ongoing Mu-activity did not reveal consistent modulatory effect of Mu-phase on corticospinal excitability in a non-preselected group Mixed-effects analysis revealed a weak but significant effect of pre-stiMulus Mu-power and ISI on corticospinal excitability