scholarly journals Stopping a response has global or nonglobal effects on the motor system depending on preparation

2012 ◽  
Vol 107 (1) ◽  
pp. 384-392 ◽  
Author(s):  
Ian Greenhouse ◽  
Caitlin L. Oldenkamp ◽  
Adam R. Aron
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Motor System ◽  
Primary Motor Cortex ◽  
Stop Signal ◽  
Stop Signal Task ◽  
Proactive Control ◽  
The Subject ◽  
Do So

Much research has focused on how people stop initiated response tendencies when instructed by a signal. Stopping of this kind appears to have global effects on the motor system. For example, by delivering transcranial magnetic stimulation (TMS) over the leg area of the primary motor cortex, it is possible to detect suppression in the leg when the hand is being stopped (Badry R et al. Suppression of human cortico-motoneuronal excitability during the stop-signal task. Clin Neurophysiol 120: 1717–1723, 2009). Here, we asked if such “global suppression” can be observed proactively, i.e., when people anticipate they might have to stop. We used a conditional stop signal task, which allows the measurement of both an “anticipation phase” (i.e., where proactive control is applied) and a “stopping” phase. TMS was delivered during the anticipation phase ( experiment 1) and also during the stopping phase ( experiments 1 and 2) to measure leg excitability. During the anticipation phase, we did not observe leg suppression, but we did during the stopping phase, consistent with Badry et al. (2009) . Moreover, when we split the subject groups into those who slowed down behaviorally (i.e., exercised proactive control) and those who did not, we found that subjects who slowed did not show leg suppression when they stopped, whereas those who did not slow did show leg suppression when they stopped. These results suggest that if subjects prepare to stop, then they do so without global effects on the motor system. Thus, preparation allows them to stop more selectively.

scholarly journals Associatively-mediated suppression of corticospinal excitability: A transcranial magnetic stimulation (TMS) study

2019 ◽  
Author(s):  
Manuel S. Seet ◽  
Evan J. Livesey ◽  
Justin A. Harris
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Response Inhibition ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Human Subjects ◽  
Stop Signal ◽  
Corticospinal Excitability ◽  
Stop Signal Task

AbstractResponse inhibition—the suppression of prepotent behaviours when they are inappropriate— has been thought to rely on executive control. Against this received wisdom, it has been argued that external cues repeatedly associated with response inhibition can come to trigger response inhibition automatically without top-down command. The current project endeavoured to provide evidence for associatively-mediated motor inhibition. We tested the hypothesis that stop-associated stimuli can, in a bottom-up fashion, directly activate inhibitory mechanisms in the motor cortex. Human subjects were first trained on a stop-signal task. Once trained, the subjects received transcranial magnetic stimulation applied over their primary motor cortex during passive observation of either the stop signal (i.e. without any need to stop a response) or an equally familiar control stimulus never associated with stopping. Analysis of motor-evoked potentials showed that corticospinal excitability was reduced during exposure to the stop signal, which likely involved stimulus-driven activation of intracortical GABAergic interneurons. This result offers evidence for the argument that, through associative learning, stop-associated stimuli can engage local inhibitory processes at the level of the motor cortex.

The effect of transcranial magnetic stimulation on the excitability of the motor neuron pools of the muscles of the lower extremities

2021 ◽  
Author(s):  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
R.N. Yakupov ◽  
V.A. Golodnova ◽  
M.V. Balykin
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Lower Extremities ◽  
Transcutaneous Electrical Stimulation ◽  
Stimulation Of

The study was conducted on 22 healthy men aged 18-23 years. The primary motor cortex innervating the lower limb was stimulated with transcranial magnetic stimulation. Using transcutaneous electrical stimulation of the spinal cord, evoked motor responses of the muscles of the lower extremities were initiated when electrodes were applied cutaneous between the spinous processes in the Th11-Th12 projection. Research protocol: Determination of the thresholds of BMO of the muscles of the lower extremities during TESCS; determination of the BMO threshold of the TA muscle in TMS; determination of the thresholds of the BMO of the muscles of the lower extremities during TESCS against the background of 80% and 90% TMS. It was found that magnetic stimulation of the motor cortex of the brain leads to an increase in the excitability of the neural structures of the lumbar thickening of the spinal cord and an improvement in neuromuscular interactions. Key words: transcranial magnetic stimulation, transcutaneous electrical stimulation of the spinal cord, neural networks, excitability, neuromuscular interactions.

A novel dual-site transcranial magnetic stimulation paradigm to probe fast facilitatory inputs from ipsilateral dorsal premotor cortex to primary motor cortex

NeuroImage ◽  
2012 ◽  
Vol 62 (1) ◽  
pp. 500-509 ◽  
Author(s):  
Sergiu Groppa ◽  
Nicole Werner-Petroll ◽  
Alexander Münchau ◽  
Günther Deuschl ◽  
Matthew F.S. Ruschworth ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Dorsal Premotor Cortex ◽  
Stimulation Paradigm ◽  
Dual Site

Motor cortex excitability and fatigue in multiple sclerosis: a transcranial magnetic stimulation study

2005 ◽  
Vol 11 (3) ◽  
pp. 316-321 ◽  
Author(s):  
J Liepert ◽  
D Mingers ◽  
C Heesen ◽  
T Bäumer ◽  
C Weiller
Keyword(s):  
Multiple Sclerosis ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Motor Task ◽  
Time Interval ◽  
Membrane Excitability ◽  
Motor Cortex Excitability ◽  
Fatigue Severity

We investigated electrophysiological correlates of fatigue in patients with multiple sclerosis (MS). Transcranial magnetic stimulation (TMS) was used to explore motor excitability in three groups of subjects: MS patients with fatigue (MS-F), MS patients without fatigue (MS-NF) and healthy control subjects. All participants had to perform a fatiguing hand-grip exercise. TMS was performed prior to and after the exercise. Prior to the motor task, MS-F patients had less inhibition in the primary motor cortex compared to both other groups. Postexercise, intracortical inhibition was still reduced in the MS-F patients compared to the MS-NF patients. In MS-F patients the postexercise time interval for normalization of the motor threshold was correlated with the fatigue severity. We conclude that MS patients with fatigue have an impairment of inhibitory circuits in their primary motor cortex. The results also indicate that fatigue severity is associated with an exercise-induced reduction of membrane excitability.

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