scholarly journals On the Effectiveness of Event-related Beta tACS on Episodic Memory Formation and Motor Cortex Excitability

2016 ◽  
Author(s):  
Verena Braun ◽  
Rodika Sokoliuk ◽  
Simon Hanslmayr
Keyword(s):  
Motor Cortex ◽  
Episodic Memory ◽  
Inferior Frontal Gyrus ◽  
Memory Formation ◽  
Frequency Range ◽  
Beta Oscillations ◽  
Healthy Human ◽  
Sham Stimulation ◽  
Motor Cortex Excitability ◽  
Beta Frequency

AbstractBackgroundTranscranial alternating current stimulation (tACS) is widely used to entrain or modulate brain oscillations in order to investigate causal relationships between oscillations and cognition.ObjectiveIn a series of experiments we here addressed the question of whether event-related, transient tACS in the beta frequency range can be used to entrain beta oscillations in two different domains: episodic memory formation and motor cortex excitability.MethodsIn experiments 1 and 2, 72 healthy human participants engaged in an incidental encoding task of verbal and non-verbal material while receiving tACS to the left and right inferior frontal gyrus (IFG) at 6.8Hz, 10.7Hz, 18.5Hz, 30Hz, 48Hz and sham stimulation for 2s during stimulus presentation.In experiment 3, tACS was administered to M1 at the individual motor beta frequency of eight subjects. We investigated the relationship between the size of TMS induced MEPs and tACS phase.ResultsBeta tACS did not affect memory performance compared to sham stimulation in experiments 1 and 2. Likewise, in experiment 3, MEP size was not modulated by the tACS phase.ConclusionsOur findings suggest that event-related, transient tACS in the beta frequency range cannot be used to modulate the formation of episodic memories or motor cortex excitability. These null-results question the effectiveness of event-related tACS to entrain beta oscillations and modulate cognition.

scholarly journals Pre-movement changes in sensorimotor beta oscillations predict motor adaptation drive

2020 ◽  
Author(s):  
Henry T Darch ◽  
Nadia L Cerminara ◽  
Iain D Gilchrist ◽  
Richard Apps
Keyword(s):  
Reaction Time ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Visuomotor Adaptation ◽  
Beta Oscillations ◽  
Scalp Eeg ◽  
Eeg Recordings ◽  
Beta Frequency ◽  
Late Adaptation ◽  
Adaptation Task

AbstractBeta frequency oscillations in scalp electroencephalography (EEG) recordings over the primary motor cortex have been associated with the preparation and execution of voluntary movements. Here, we test whether changes in beta frequency are related to the preparation of adapted movements in human, and whether such effects generalise to other species (cat). Eleven healthy adult humans performed a joystick visuomotor adaptation task. Beta (15-25Hz) scalp EEG signals recorded over the motor cortex during a pre-movement preparatory phase were, on average, significantly reduced in amplitude during early adaptation trials compared to baseline or late adaptation trials (p=0.01). The changes in beta were not related to measurements of reaction time or duration of the reach. We also recorded LFP activity within the primary motor cortex of three cats during a prism visuomotor adaptation task. Analysis of these signals revealed similar reductions in motor cortical LFP beta frequencies during early adaptation. This effect was also present when controlling for any influence of the reaction time and reaching duration. Overall, the results are consistent with a reduction in pre-movement beta oscillations predicting an increase in adaptive drive in upcoming task performance when motor errors are largest in magnitude and the rate of adaptation is greatest.

scholarly journals The Effects of 1 mA tACS and tRNS on Children/Adolescents and Adults: Investigating Age and Sensitivity to Sham Stimulation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Maike Splittgerber ◽  
Jan Hendrik Suwelack ◽  
Navah Ester Kadish ◽  
Vera Moliadze
Keyword(s):  
Motor Cortex ◽  
Children And Adolescents ◽  
Random Noise ◽  
Short Interval ◽  
Single Pulse ◽  
Individual Response ◽  
Healthy Children ◽  
Sham Stimulation ◽  
Motor Cortex Excitability ◽  
The Individual

The aim of this study was to investigate the effect of transcranial random noise (tRNS) and transcranial alternating current (tACS) stimulation on motor cortex excitability in healthy children and adolescents. Additionally, based on our recent results on the individual response to sham in adults, we explored this effect in the pediatric population. We included 15 children and adolescents (10–16 years) and 28 adults (20–30 years). Participants were stimulated four times with 20 Hz and 140 Hz tACS, tRNS, and sham stimulation (1 mA) for 10 minutes over the left M1HAND. Single-pulse MEPs (motor evoked potential), short-interval intracortical inhibition, and facilitation were measured by TMS before and after stimulation (baseline, 0, 30, 60 minutes). We also investigated aspects of tolerability. According to the individual MEPs response immediately after sham stimulation compared to baseline (Wilcoxon signed-rank test), subjects were regarded as responders or nonresponders to sham. We did not find a significant age effect. Regardless of age, 140 Hz tACS led to increased excitability. Incidence and intensity of side effects did not differ between age groups or type of stimulation. Analyses on responders and nonresponders to sham stimulation showed effects of 140 Hz, 20 Hz tACS, and tRNS on single-pulse MEPs only for nonresponders. In this study, children and adolescents responded to 1 mA tRNS and tACS comparably to adults regarding the modulation of motor cortex excitability. This study contributes to the findings that noninvasive brain stimulation is well tolerated in children and adolescents including tACS, which has not been studied before. Finally, our study supports a modulating role of sensitivity to sham stimulation on responsiveness to a broader stimulation and age range.

Effects of D-Cycloserine on the Primary Motor Cortex Excitability in Healthy Human Subjects: A Paired-Pulse-Tms Protocol

2021 ◽  
Vol 89 (9) ◽  
pp. S329-S330
Author(s):  
Shiwen Yuan ◽  
Joshua Brown ◽  
William Devries ◽  
Gregory Sahlem ◽  
Mark S. George ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Human Subjects ◽  
Healthy Human ◽  
Paired Pulse ◽  
Motor Cortex Excitability ◽  
Healthy Human Subjects

scholarly journals 20 Hz Transcranial Alternating Current Stimulation Inhibits Observation-Execution-Related Motor Cortex Excitability

2021 ◽  
Vol 11 (10) ◽  
pp. 979
Author(s):  
Lijuan Wang ◽  
Michael A. Nitsche ◽  
Volker R. Zschorlich ◽  
Hui Liu ◽  
Zhaowei Kong ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Action Observation ◽  
Alternating Current ◽  
Sham Stimulation ◽  
Cohen’S D ◽  
Right Hand ◽  
Motor Cortex Excitability ◽  
Transcranial Alternating Current Stimulation ◽  
Cohen's D ◽  
Time Point

The present study aimed to investigate the effect of transcranial alternating current stimulation (tACS) on the primary motor cortex (M1) during action observation, and subsequent action execution, on motor cortex excitability. The participants received tACS at 10 Hz or 20 Hz, or a sham stimulation over the left M1 for 10 min while they observed a video displaying a repeated button-tapping task using the right hand, and then performed an identical task with their right hand. Motor-evoked potential (MEP) amplitudes were measured before (T0) and after the action observation paired with tACS or a sham stimulation (T1), and after the performance of the action (T2). The results showed that MEPs were significantly reduced at time point T1 (p = 0.042, Cohen’s d = 0.611) and T2 (p = 0.0003, Cohen’s d = 0.852) in the 20 Hz tACS condition, in contrast with the sham stimulation. There was a significantly smaller MEP amplitude at time point T2 in the 20 Hz tACS condition, as compared to the 10 Hz tACS condition (p = 0.01, Cohen’s d = 0.622), but the MEP amplitude did not significantly change at time point T1 between the 20 Hz and 10 Hz tACS conditions (p = 0.136, Cohen’s d = 0.536). There were no significant differences at time point T1 and T2 between the 10 Hz tACS condition and the sham stimulation. We conclude that 20 Hz tACS during action observation inhibited motor cortex excitability and subsequently inhibited execution-related motor cortex excitability. The effects of tACS on task-related motor cortex excitability are frequency-dependent.

scholarly journals Brain oscillations track the formation of episodic memories in the real world

2016 ◽  
Author(s):  
Benjamin Griffiths ◽  
Ali Mazaheri ◽  
Stefan Debener ◽  
Simon Hanslmayr
Keyword(s):  
Episodic Memory ◽  
Real World ◽  
Medial Temporal Lobe ◽  
Spatial Clustering ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Blind Spot ◽  
Memory Formation ◽  
The Real ◽  
Beta Power

Despite the well-known influence of environmental context on episodic memory, little has been done to enhance contextual richness within the lab. This leaves a blind spot lingering over the neuronal correlates of episodic memory formation in the real world. To address this, we presented participants with series of words to memorise along a pre-designated route across campus. Meanwhile, a mobile EEG system acquired the associated neural activity. Replicating lab-based subsequent memory effects (SMEs), we identified significant low-frequency power decreases, including beta power decreases over the left inferior frontal gyrus. Additionally, the paradigm enabled us to dissociate the oscillatory correlates of temporal and spatial clustering. Specifically, we found spatially clustered items exhibited significantly greater theta power decreases within the left medial temporal lobe than temporally clustered items. These findings go beyond lab-based studies, which are limited in their capabilities to investigate environmental contextual factors that guide memory formation.

Efficacy of tRNS and 140 Hz tACS on motor cortex excitability seemingly dependent on sensitivity to sham stimulation

2019 ◽  
Vol 237 (11) ◽  
pp. 2885-2895 ◽  
Author(s):  
Viktoria Kortuem ◽  
Navah Ester Kadish ◽  
Michael Siniatchkin ◽  
Vera Moliadze
Keyword(s):  
Motor Cortex ◽  
Sham Stimulation ◽  
Motor Cortex Excitability

scholarly journals Pre-movement changes in sensorimotor beta oscillations predict motor adaptation drive

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Henry T. Darch ◽  
Nadia L. Cerminara ◽  
Iain D. Gilchrist ◽  
Richard Apps
Keyword(s):  
Reaction Time ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Field Potential ◽  
Visuomotor Adaptation ◽  
Beta Oscillations ◽  
Scalp Eeg ◽  
Eeg Recordings ◽  
Beta Frequency ◽  
Adaptation Task

Abstract Beta frequency oscillations in scalp electroencephalography (EEG) recordings over the primary motor cortex have been associated with the preparation and execution of voluntary movements. Here, we test whether changes in beta frequency are related to the preparation of adapted movements in human, and whether such effects generalise to other species (cat). Eleven healthy adult humans performed a joystick visuomotor adaptation task. Beta (15–25 Hz) scalp EEG signals recorded over the motor cortex during a pre-movement preparatory phase were, on average, significantly reduced in amplitude during early adaptation trials compared to baseline, late adaptation, or aftereffect trials. The changes in beta were not related to measurements of reaction time or reach duration. We also recorded local field potential (LFP) activity within the primary motor cortex of three cats during a prism visuomotor adaptation task. Analysis of these signals revealed similar reductions in motor cortical LFP beta frequencies during early adaptation. This effect was present when controlling for any influence of the reaction time and reach duration. Overall, the results are consistent with a reduction in pre-movement beta oscillations predicting an increase in adaptive drive in upcoming task performance when motor errors are largest in magnitude and the rate of adaptation is greatest.

Cerebello-spinal tDCS in ataxia

Neurology ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. e1090-e1101 ◽  
Author(s):  
Alberto Benussi ◽  
Valentina Dell'Era ◽  
Valentina Cantoni ◽  
Elisa Bonetta ◽  
Roberto Grasso ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Rating Scale ◽  
Double Blind ◽  
Clinical Trial Registration ◽  
Sham Stimulation ◽  
Motor Cortex Excitability ◽  
Before And After ◽  
Cerebellar Brain Inhibition

ObjectiveTo investigate whether a 2-week treatment with cerebellar anodal and spinal cathodal transcranial direct current stimulation (tDCS) could reduce symptoms in patients with neurodegenerative ataxia and could modulate cerebello-motor connectivity at the short and long terms.MethodsWe performed a double-blind, randomized, sham-controlled, crossover trial with cerebello-spinal tDCS (5 d/wk for 2 weeks) in 20 patients with neurodegenerative ataxia. Each patient underwent a clinical evaluation before and after real tDCS or sham stimulation. A follow-up evaluation was performed at 1 and 3 months with a crossover washout period of 3 months. Cerebello-motor connectivity was evaluated with transcranial magnetic stimulation at baseline and at each follow-up.ResultsCerebello-spinal tDCS showed a significant improvement in all performance scores (Scale for the Assessment and Rating of Ataxia, International Cooperative Ataxia Rating Scale, 9-Hole Peg Test, 8-m walking time), in motor cortex excitability, and in cerebellar brain inhibition compared to sham stimulation.ConclusionsA 2-week treatment with cerebello-spinal tDCS reduces symptoms in patients with ataxia and restores motor cortex inhibition exerted by cerebellar structures. Cerebello-spinal tDCS might represent a promising future therapeutic and rehabilitative approach in patients with neurodegenerative ataxia, still an orphan disorder of any pharmacologic intervention.Clinical trial registrationNCT03120013.Classification of evidenceThis study provides Class II evidence that cerebello-spinal stimulation is effective and safe in cerebellar ataxia.

scholarly journals Long-latency modulation of motor cortex excitability by ipsilateral posterior inferior frontal gyrus and pre-supplementary motor area

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Francesca Fiori ◽  
Emilio Chiappini ◽  
Marco Soriano ◽  
Riccardo Paracampo ◽  
Vincenzo Romei ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Supplementary Motor Area ◽  
Inferior Frontal Gyrus ◽  
Motor Area ◽  
Long Latency ◽  
Motor Cortex Excitability
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