On the effectiveness of event-related beta tACS on episodic memory formation and motor cortex excitability

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.

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'Direct' and 'crossed' modulation of human motor cortex excitability following exercise

Neuroscience Letters ◽

10.1016/s0304-3940(96)13010-x ◽

1996 ◽

Vol 216 (2) ◽

pp. 97-100 ◽

Cited By ~ 1

Author(s):

C Bonato

Keyword(s):

Motor Cortex ◽

Human Motor Cortex ◽

Motor Cortex Excitability ◽

Human Motor

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Increase in motor-cortex excitability after constraint-induced movement therapy in patients with congenital stroke

Klinische Neurophysiologie ◽

10.1055/s-2006-939319 ◽

2006 ◽

Vol 37 (01) ◽

Author(s):

M Walther ◽

V Brodbeck ◽

H Jünger ◽

M Staudt ◽

...

Keyword(s):

Motor Cortex ◽

Movement Therapy ◽

Constraint Induced Movement Therapy ◽

Motor Cortex Excitability

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Knowledge is power: prior knowledge aids memory formation for both congruent and incongruent events, but in different ways.

10.31234/osf.io/um4ga ◽

2017 ◽

Author(s):

Andrea Greve ◽

Elisa Cooper ◽

Roni Tibon ◽

Richard Henson

Keyword(s):

Episodic Memory ◽

Prior Knowledge ◽

Memory Performance ◽

Memory Formation ◽

Memory Test ◽

World Knowledge ◽

Apparent Paradox ◽

Power Prior

Events that conform to our expectations, i.e, are congruent with our world knowledge or schemas, are better remembered than unrelated events. Yet events that conflict with schemas can also be remembered better. We examined this apparent paradox in four experiments, in which schemas were established by training ordinal relationships between randomly-paired objects, while episodic memory was tested for the number of objects on each trial. Better memory was found for both congruent and incongruent trials, relative to unrelated trials, producing memory performance that was a “U-shaped” function of congruency. Furthermore, the incongruency advantage, but not congruency advantage, emerged even if the information probed by the memory test was irrelevant to the schema, while the congruency advantage, but not incongruency advantage, also emerged after initial encoding. Schemas therefore augment episodic memory in multiple ways, depending on the match between novel and existing information.

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Faculty Opinions recommendation of Memory formation in the motor cortex ipsilateral to a training hand.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1093850.548777 ◽

2007 ◽

Author(s):

Roger Lemon

Keyword(s):

Motor Cortex ◽

Memory Formation

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Effect of opposing needling on motor cortex excitability in healthy participants and in patients with post-stroke hemiplegia: study protocol for a single-blind, randomised controlled trial

Trials ◽

10.1186/s13063-021-05443-x ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Mindong Xu ◽

Yinyu Zi ◽

Jianlu Wu ◽

Nenggui Xu ◽

Liming Lu ◽

...

Keyword(s):

Motor Cortex ◽

Primary Motor Cortex ◽

Motor Evoked Potentials ◽

Controlled Trial ◽

Secondary Outcome ◽

Post Stroke ◽

Motor Cortex Excitability ◽

Opposing Needling ◽

Single Blind ◽

Healthy Participants

Abstract Background Opposing needling has an obvious curative effect in the treatment of post-stroke hemiplegia; however, the mechanism of the opposing needling in the treatment of post-stroke hemiplegia is still not clear. The purpose of this study is to investigate the effect of opposing needling on the excitability of primary motor cortex (M1) of healthy participants and patients with post-stroke hemiplegia, which may provide insight into the mechanisms of opposing needling in treating post-stroke hemiplegia. Methods This will be a single-blind, randomised, sham-controlled trial in which 80 healthy participants and 40 patients with post-stroke hemiplegia will be recruited. Healthy participants will be randomised 1:1:1:1 to the 2-Hz, 50-Hz, 100-Hz, and sham electroacupuncture groups. Patients with post-stroke hemiplegia will be randomised 1:1 to the opposing needling or conventional treatment groups. The M1 will be located in all groups by using neuroimaging-based navigation. The stimulator coil of transcranial magnetic stimulation (TMS) will be moved over the left and right M1 in order to identify the TMS hotspot, followed by a recording of resting motor thresholds (RMTs) and motor-evoked potentials (MEPs) of the thenar muscles induced by TMS before and after the intervention. The primary outcome measure will be the percent change in the RMTs of the thenar muscles at baseline and after the intervention. The secondary outcome measures will be the amplitude (μV) and latency (ms) of the MEPs of the thenar muscles at baseline and after the intervention. Discussion The aim of this trial is to explore the effect of opposing needling on the excitability of M1 of healthy participants and patients with post-stroke hemiplegia. Trial registration Chinese Clinical Trial Registry ChiCTR1900028138. Registered on 13 December 2019.

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Transcranial Magnetic Stimulation as a Tool to Investigate Motor Cortex Excitability in Sport

Brain Sciences ◽

10.3390/brainsci11040432 ◽

2021 ◽

Vol 11 (4) ◽

pp. 432

Author(s):

Fiorenzo Moscatelli ◽

Antonietta Messina ◽

Anna Valenzano ◽

Vincenzo Monda ◽

Monica Salerno ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Motor Coordination ◽

Cortical Excitability ◽

Non Invasive ◽

Motor Cortex Excitability ◽

Invasive Method ◽

And Control ◽

The Impact

Transcranial magnetic stimulation, since its introduction in 1985, has brought important innovations to the study of cortical excitability as it is a non-invasive method and, therefore, can be used both in healthy and sick subjects. Since the introduction of this cortical stimulation technique, it has been possible to deepen the neurophysiological aspects of motor activation and control. In this narrative review, we want to provide a brief overview regarding TMS as a tool to investigate changes in cortex excitability in athletes and highlight how this tool can be used to investigate the acute and chronic responses of the motor cortex in sport science. The parameters that could be used for the evaluation of cortical excitability and the relative relationship with motor coordination and muscle fatigue, will be also analyzed. Repetitive physical training is generally considered as a principal strategy for acquiring a motor skill, and this process can elicit cortical motor representational changes referred to as use-dependent plasticity. In training settings, physical practice combined with the observation of target movements can enhance cortical excitability and facilitate the process of learning. The data to date suggest that TMS is a valid technique to investigate the changes in motor cortex excitability in trained and untrained subjects. Recently, interest in the possible ergogenic effect of non-invasive brain stimulation in sport is growing and therefore in the future it could be useful to conduct new experiments to evaluate the impact on learning and motor performance of these techniques.

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