scholarly journals Sensorimotor Robotic Measures of tDCS- and HD-tDCS-Enhanced Motor Learning in Children

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Lauran Cole ◽  
Sean P. Dukelow ◽  
Adrianna Giuffre ◽  
Alberto Nettel-Aguirre ◽  
Megan J. Metzler ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Primary Motor Cortex ◽  
Medium Effect ◽  
Sensorimotor Function ◽  
Anodal Tdcs ◽  
Visually Guided ◽  
Direction Error ◽  
Visually Guided Reaching ◽  
The Right

Transcranial direct-current stimulation (tDCS) enhances motor learning in adults. We have demonstrated that anodal tDCS and high-definition (HD) tDCS of the motor cortex can enhance motor skill acquisition in children, but behavioral mechanisms remain unknown. Robotics can objectively quantify complex sensorimotor functions to better understand mechanisms of motor learning. We aimed to characterize changes in sensorimotor function induced by tDCS and HD-tDCS paired motor learning in children within an interventional trial. Healthy, right-handed children (12–18 y) were randomized to anodal tDCS, HD-tDCS, or sham targeting the right primary motor cortex during left-hand Purdue pegboard test (PPT) training over five consecutive days. A KINARM robotic protocol quantifying proprioception, kinesthesia, visually guided reaching, and an object hit task was completed at baseline, posttraining, and six weeks later. Effects of the treatment group and training on changes in sensorimotor parameters were explored. Twenty-four children (median 15.5 years, 52% female) completed all measures. Compared to sham, both tDCS and HD-tDCS demonstrated enhanced motor learning with medium effect sizes. At baseline, multiple KINARM measures correlated with PPT performance. Following training, visually guided reaching in all groups was faster and required less corrective movements in the trained arm (H(2) = 9.250,p=0.010). Aspects of kinesthesia including initial direction error improved across groups with sustained effects at follow-up (H(2) = 9.000,p=0.011). No changes with training or stimulation were observed for position sense. For the object hit task, the HD-tDCS group moved more quickly with the right hand compared to sham at posttraining (χ2(2) = 6.255,p=0.044). Robotics can quantify complex sensorimotor function within neuromodulator motor learning trials in children. Correlations with PPT performance suggest that KINARM metrics can assess motor learning effects. Understanding how tDCS and HD-tDCS enhance motor learning may be improved with robotic outcomes though specific mechanisms remain to be defined. Exploring mechanisms of neuromodulation may advance therapeutic approaches in children with cerebral palsy and other disabilities.

scholarly journals Cognitive control affects motor learning through local variations in GABA within the primary motor cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuki Maruyama ◽  
Masaki Fukunaga ◽  
Sho K. Sugawara ◽  
Yuki H. Hamano ◽  
Tetsuya Yamamoto ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Motor Learning ◽  
Cognitive Control ◽  
Primary Motor Cortex ◽  
Resonance Spectroscopy ◽  
Motor Sequence ◽  
Sensorimotor Network ◽  
Preparatory Activity ◽  
The Right

AbstractThe primary motor cortex (M1) is crucial for motor learning; however, its interaction with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides learning-related information critical for the flexible cognitive control that is required for practice. We assessed network-level changes during sequential finger tapping learning under speed pressure by combining magnetic resonance spectroscopy and task and resting-state functional magnetic resonance imaging. There was a motor learning-related increase in preparatory activity in the fronto-parietal regions, including the right M1, overlapping the FPN and sensorimotor network (SMN). Learning-related increases in M1-seeded functional connectivity with the FPN, but not the SMN, were associated with decreased GABA/glutamate ratio in the M1, which were more prominent in the parietal than the frontal region. A decrease in the GABA/glutamate ratio in the right M1 was positively correlated with improvements in task performance (p = 0.042). Our findings indicate that motor learning driven by cognitive control is associated with local variations in the GABA/glutamate ratio in the M1 that reflects remote connectivity with the FPN, representing network-level motor sequence learning formations.

scholarly journals Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Laura Georgescu Margarint ◽  
Ioana Antoaneta Georgescu ◽  
Carmen Denise Mihaela Zahiu ◽  
Stefan-Alexandru Tirlea ◽  
Alexandru Rǎzvan Şteopoaie ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Kainic Acid ◽  
Primary Motor Cortex ◽  
Low Frequency ◽  
Muscular Activity ◽  
Cerebellar Hemisphere ◽  
Interhemispheric Coherence ◽  
General Locomotor Activity ◽  
Complex Circuits ◽  
The Right

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.

scholarly journals Comparison of repeated transcranial stimulation and transcranial direct-current stimulation on primary motor cortex excitability and inhibition: A pilot study

2018 ◽  
pp. 59-67 ◽  
Author(s):  
Vincent Cabibel ◽  
Makii Muthalib ◽  
Jérôme Froger ◽  
Stéphane Perrey
Keyword(s):  
Pilot Study ◽  
Motor Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
High Definition ◽  
Direct Current Stimulation ◽  
Motor Cortex Excitability ◽  
The Right

Repeated transcranial magnetic stimulation (rTMS) is a well-known clinical neuromodulation technique, but transcranial direct-current stimulation (tDCS) is rapidly growing interest for neurorehabilitation applications. Both methods (contralesional hemisphere inhibitory low-frequency: LF-rTMS or lesional hemisphere excitatory anodal: a-tDCS) have been employed to modify the interhemispheric imbalance following stroke. The aim of this pilot study was to compare aHD-tDCS (anodal high-definition tDCS) of the left M1 (2 mA, 20 min) and LF-rTMS of the right M1 (1 Hz, 20 min) to enhance excitability and reduce inhibition of the left primary motor cortex (M1) in five healthy subjects. Single-pulse TMS was used to elicit resting and active (low level muscle contraction, 5% of maximal electromyographic signal) motor-evoked potentials (MEPs) and cortical silent periods (CSPs) from the right and left extensor carpi radialis muscles at Baseline, immediately and 20 min (Post-Stim-20) after the end of each stimulation protocol. LF-rTMS or aHD-tDCS significantly increased right M1 resting and active MEP amplitude at Post-Stim-20 without any CSP modulation and with no difference between methods. In conclusion, this pilot study reported unexpected M1 excitability changes, which most likely stems from variability, which is a major concern in the field to consider.

Transcranial static magnetic stimulation over the primary motor cortex alters sequential implicit motor learning

2019 ◽  
Vol 696 ◽  
pp. 33-37 ◽  
Author(s):  
Ippei Nojima ◽  
Tatsunori Watanabe ◽  
Tomoya Gyoda ◽  
Hisato Sugata ◽  
Takashi Ikeda ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Implicit Motor Learning ◽  
Implicit Motor

BDNF Val66Met polymorphism is associated with abnormal interhemispheric transfer of a newly acquired motor skill

2014 ◽  
Vol 111 (10) ◽  
pp. 2094-2102 ◽  
Author(s):  
Olivier Morin-Moncet ◽  
Vincent Beaumont ◽  
Louis de Beaumont ◽  
Jean-Francois Lepage ◽  
Hugo Théoret
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Motor Skill ◽  
Interhemispheric Transfer ◽  
Corticospinal Excitability ◽  
Genetic Group ◽  
Val66met Polymorphism ◽  
Genotype Group ◽  
Left Hand ◽  
The Right

Recent data suggest that the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene can alter cortical plasticity within the motor cortex of carriers, which exhibits abnormally low rates of cortical reorganization after repetitive motor tasks. To verify whether long-term retention of a motor skill is also modulated by the presence of the polymorphism, 20 participants (10 Val66Val, 10 Val66Met) were tested twice at a 1-wk interval. During each visit, excitability of the motor cortex was measured by transcranial magnetic stimulations (TMS) before and after performance of a procedural motor learning task (serial reaction time task) designed to study sequence-specific learning of the right hand and sequence-specific transfer from the right to the left hand. Behavioral results showed a motor learning effect that persisted for at least a week and task-related increases in corticospinal excitability identical for both sessions and without distinction for genetic group. Sequence-specific transfer of the motor skill from the right hand to the left hand was greater in session 2 than in session 1 only in the Val66Met genetic group. Further analysis revealed that the sequence-specific transfer occurred equally at both sessions in the Val66Val genotype group. In the Val66Met genotype group, sequence-specific transfer did not occur at session 1 but did at session 2. These data suggest a limited impact of Val66Met polymorphism on the learning and retention of a complex motor skill and its associated changes in corticospinal excitability over time, and a possible modulation of the interhemispheric transfer of procedural learning.

scholarly journals Role of the Ipsilateral Motor Cortex in Voluntary Movement

1997 ◽  
Vol 24 (04) ◽  
pp. 284-291 ◽  
Author(s):  
Robert Chen ◽  
Leonardo G. Cohen ◽  
Mark Hallett
Keyword(s):  
Motor Cortex ◽  
Functional Recovery ◽  
Voluntary Movement ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Normal Subjects ◽  
Older Children ◽  
Focal Brain Injury ◽  
Complex Sequences ◽  
The Right

ABSTRACT:The ipsilateral primary motor cortex (M1) plays a role in voluntary movement. In our studies, we used repetitive transcranial magnetic stimulation (rTMS) to study the effects of transient disruption of the ipsilateral M1 on the performance of finger sequences in right-handed normal subjects. Stimulation of the M1 ipsilateral to the movement induced timing errors in both simple and complex sequences performed with either hand, but with complex sequences, the effects were more pronounced with the left-sided stimulation. Recent studies in both animals and humans have confirmed the traditional view that ipsilateral projections from M1 to the upper limb are mainly directed to truncal and proximal muscles, with little evidence for direct connections to distal muscles. The ipsilateral motor pathway appears to be an important mechanism for functional recovery after focal brain injury during infancy, but its role in functional recovery for older children and adults has not yet been clearly demonstrated. There is increasing evidence from studies using different methodologies such as rTMS, functional imaging and movement-related cortical potentials, that M1 is involved in ipsilateral hand movements, with greater involvement in more complex tasks and the left hemisphere playing a greater role than the right.

Neural representations of the target (goal) of visually guided arm movements in three motor areas of the monkey

1990 ◽  
Vol 64 (1) ◽  
pp. 164-178 ◽  
Author(s):  
G. E. Alexander ◽  
M. D. Crutcher
Keyword(s):  
Primary Motor Cortex ◽  
Cell Activity ◽  
Motor Area ◽  
Visually Guided ◽  
Spatial Features ◽  
Tracking Tasks ◽  
Neural Representations ◽  
Preparatory Activity ◽  
Standard Task ◽  
The Right

1. This study was designed to determine whether the supplementary motor area (SMA), the primary motor cortex (MC), and the putamen, all of which are components of the basal ganglia-thalamocortical “motor circuit,” contain neural representations of the target or goal of a movement, independent of specific features of the movement itself. Four rhesus monkeys were trained to perform two visuomotor delayed step-tracking tasks in which the subject used a cursor to track targets on a display screen by making flexion and extension movements of the elbow. Single-cell activity was recorded from the SMA, MC, and putamen while the monkeys performed the two tasks. In the Standard task, the cursor and the forearm moved in the same direction. The Cursor/Limb Inversion task was identical to the Standard task except that there was an inverse relationship between the directions of movement of the forearm and cursor. Together, these tasks dissociated the spatial features of the target or goal of the movement from those of the movement itself. Both tasks also included features that made it possible to distinguish neuronal activity related to the preparation for movement from that related to movement execution. A total of 554 directionally selective, task-related neurons were tested with both tasks (SMA, 207; MC, 198; putamen, 149). 2. Two types of directionally selective preparatory activity were seen in each motor area. Cells with target-dependent preparatory activity showed selective discharge prior to all preplanned movements of the cursor toward one of the side targets (right or left), irrespective of whether the limb movement involved extension or flexion of the elbow. Comparable proportions of target-dependent preparatory cells were seen in the SMA (36%), MC (40%), and putamen (38%). Cells with limb-dependent preparatory activity showed selective discharge prior to all preplanned elbow movements in a particular direction (extension or flexion), irrespective of whether the target to which the cursor was moved was located on the right or left side of the display. The SMA contained a higher proportion of limb-dependent preparatory cells (40%) than either MC (15%) or putamen (9%). 3. Two types of directionally selective movement-related activity were also seen in each motor area.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Electrifying discourse: Anodal tDCS of the primary motor cortex selectively reduces action appraisal in naturalistic narratives

Cortex ◽  
2020 ◽  
Vol 132 ◽  
pp. 460-472
Author(s):  
Agustina Birba ◽  
Francesca Vitale ◽  
Iván Padrón ◽  
Martín Dottori ◽  
Manuel de Vega ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Anodal Tdcs
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