Influence of task-related ipsilateral hand movement on motor cortex excitability

Zaaroor, Menashe; Pratt, Hillel; Starr, Arnold

doi:10.1016/s1388-2457(01)00516-8

Cited by 11 publications

(5 citation statements)

References 33 publications

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“…Even viewing a mirror image of the ipsilateral hand has been found to excite the ipsilateral M1 pathway (9), as can simple finger movements (20). In contrast, some studies have also suggested that both inhibition and excitation may be present owing to unilateral movement (26,32). A recent review by Carson (6) assesses the means by which excitatory and inhibitory interactions take place at multiple levels of the neuraxis during unilateral and bilateral tasks.…”

Section: Discussionmentioning

confidence: 99%

Increased spinal reflex excitability is not associated with neural plasticity underlying the cross-education effect

Lagerquist¹,

Zehr²,

Docherty³

2006

Journal of Applied Physiology

122

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The purpose of this study was to examine the effects of a 5-wk unilateral, isometric strength-training program on plasticity in the spinal Hoffmann (H-) reflex in both the trained and untrained legs. Sixteen participants, 22-42 yr old, were assigned to either a control (n = 6) or an exercise group (n = 10). Both groups were tested for plantar flexion maximal voluntary isometric contractions (MVIC) and soleus H-reflex amplitude in both limbs, at the beginning and at the end of a 5-wk interval. Participants in the exercise group showed significantly increased MVIC in both legs after training (P < 0.05), whereas strength was unchanged in the control group for either leg. Subjects in the exercise group displayed increased (P < 0.05) H-reflex amplitudes on the ascending limb of the recruitment curve (at an equivalent M wave of 5% of the maximal M wave, H(A)) only in the trained leg. Maximal H-reflex and M-wave remained unchanged with training. Increased amplitude of H(A) in the trained limb concurrent with increased strength suggests that spinal mechanisms may underlie the changes in strength, possibly because of increased alpha-motoneuronal excitability or reduced presynaptic inhibition. Despite a similar increase in strength in the contralateral limb of the exercise group, H(A) amplitude was unchanged. We conclude that the cross-education effect of strength training may be due to supraspinal to a greater extent than spinal mechanisms.

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Section: Discussionmentioning

confidence: 99%

Increased spinal reflex excitability is not associated with neural plasticity underlying the cross-education effect

Lagerquist¹,

Zehr²,

Docherty³

2006

Journal of Applied Physiology

122

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“…We used an experimental design similar to the one we used in a study of ipsilateral motor excitability during movement [34] that avoids an overt sensory cue, while allowing experimental control of TMS timing relative to both the movement and the cue to move. Sub-threshold TMS was employed to study the time course of motor excitability that was measured by probability of activating motoneurones (MEP probability) and by the degree of motor activation (MEP amplitude) to reveal both excitatory and inhibitory effects.…”

Section: Introductionmentioning

confidence: 99%

Time course of motor excitability before and after a task-related movement

Zaaroor

Pratt

Starr

2003

Neurophysiologie Clinique/Clinical Neurophysiology

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Aims of the study. -The time course of motor excitability during a task-related unilateral right thumb movement was studied using sub-threshold transcranial magnetic stimulation (TMS) to the contralateral left motor cortex. The level of stimulation evoked a motor evoked potential (MEP) in the thumb when the subject was at rest in approximately 10% of the trials.Methods. -Subjects made a brief right thumb movement to the predictable omission of regularly presented tone bursts allowing experimental definition of TMS relative to the cue to move. Motor cortical excitability was characterized by amplitude and/or probability of eliciting MEPs.Results. -There were four periods of altered motor excitability during task performance compared to a control resting state: a first period of weak facilitation before movement between -500 to -200 ms, a second period without increased excitability approximately 150 ms before movement onset when MEPs amplitude was below that seen in rest, a third period of strong facilitation between -100 ms before movement and +200 ms after facilitation and a fourth period of weak facilitation between +200 to +500 ms.Conclusion. -These results show that during performance of a task requiring a motor response, motor cortical excitability is increased above resting for hundreds of millisecond before and after the response, except for a transient period between 75 and 150 ms prior to movement onset. The temporal pattern of these excitability changes is compatible with multiple excitatory and inhibitory inputs interacting on motor cortex.© 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. RésuméObjectif de l'étude. -Étudier le décours temporel de l'excitabilité motrice pendant une tâche de mouvement du pouce droit, en délivrant une stimulation magnétique transcranienne (TMS) à un niveau infra-liminaire sur le cortex moteur contralatéral. À ce niveau de stimulation, nous avons obtenu l'apparition d'un potentiel évoqué moteur (PEM) dans le pouce, avec les sujets au repos, dans 10 % des essais.Méthodes. -Les sujets faisaient un bref mouvement du pouce droit en réponse à l'omission (prédictible) de bruits blancs présentés régulièrement. Ceci nous a permis de définir différentes fenêtres d'application de la TMS, avant ou après le mouvement du doigt. L'excitabilité motrice corticale était alors définie par l'amplitude et/ou la probabilité de produire un PEM.Résultats. -Il est apparu 4 périodes au cours desquelles l'excitabilité motrice était altérée en comparaison à un niveau de repos : une première période de faible facilitation avant le mouvement, entre -500 et -200 ms, une seconde période sans augmentation de l'excitabilité, environ 150 ms avant le début du mouvement (l'amplitude des PEM étant inférieure à celle pendant les périodes de repos), une troisième période de forte facilitation entre -100 ms avant le mouvement et +200 ms après la facilitation, enfin une quatrième période de faible facilitation entre +200 et +500 ms.Conclusion. -Ces résultats montrent que, pend...

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“…This protocol assured that subjects could neither predict nor adapt to the disturbance. Haptic parameters were adjusted to avoid overlap of EEG signals related to cognitive or visual processing associated with the beginning of the trial [8,15]. Specifically, haptically rendered virtual table stiffness, static and dynamic friction, and environment viscosity were tuned in the experimental software, based on the preliminary pilot tests.…”

Section: Methodsmentioning

confidence: 99%

Brain Responses to Errors During 3D Motion in a Hapto-Visual VR

Yazmir

Reiner

Pratt

et al. 2016

Haptics: Perception, Devices, Control, and Applications

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Abstract. We investigated brain potentials recorded by electroencephalography (EEG) signals in response to unpredictable haptic/kinesthetic disturbances to a continuously moving object in a hapto-visual 3D virtual world that highly resembles reality. Participants moved a virtual object from an initial position to a target position in the virtual environment. A large cylinder obscured part of the motion between the origin and the target. The position of the emerging object under the cylinder is disturbed, and hence unexpected, for part of the scenarios. This disturbance is perceived as an error. We examined the EEG signals locked to the error. Our results show a consistent disturbance-locked potential with an early negative peak followed by a positive peak. Peak-to-peak amplitude increased with the disturbance magnitude. Source estimation at the time of the negative and positive peaks revealed a strong activity in the vicinity of Brodmann area (BA) 7, known to be involved in hapto-visual integration and in the neural computation of dynamic motor errors. These results demonstrate the presence of haptic-disturbance-related brain activity under conditions of continuous motion. Results further suggest a feedback signal for error detection and correction in EEG-based Brain-Computer Interfaces (BCI) in applications such as telesurgery, manipulation of remote objects and rehabilitation.

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Influence of task-related ipsilateral hand movement on motor cortex excitability

Cited by 11 publications

References 33 publications

Increased spinal reflex excitability is not associated with neural plasticity underlying the cross-education effect

Increased spinal reflex excitability is not associated with neural plasticity underlying the cross-education effect

Time course of motor excitability before and after a task-related movement

Brain Responses to Errors During 3D Motion in a Hapto-Visual VR

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