Influence of Transcranial Direct Stimulation Current on Motor Learning of Young Adults

Study Overview
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Brief Summary
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Motor learning occurs with structural and functional modifications in neural networks that meet a certain demand. The improvement of performance in diverse activities is a measure of learning, as well as the generalization and transference of this capacity. Transcranial direct current stimulation (tDCS) is a modulation technique of brain activity that modifies cortical excitability, causing changes in motor evoked potentials that influence motor learning. Modifications similar to the long-term potentiation, essential for learning processes, have also been described after applying tDCS. The primary motor cortex is the area of stimulation where there is more robust evidence in favor of increased motor learning. PURPOSE: to investigate the effects of anodic tDCS on the learning of sequential finger movements in young and healthy individuals.

Detailed Description
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Thirty-six young healthy individuals, right-handed, with no deficits that difficult the performance of the procedures will participate in the study. These individuals will be randomly divided into an experimental group that will perform the motor training of a sequential task of fingers simultaneously to the anodic tDCS on the contralateral motor cortex the trained hand and a control group that will perform the same training simultaneously the stimulation placebo (simulated in the same region of the experimental group). The training will consist of 8 blocks with 300 repetitions of sequential finger movements performed with only the right upper limb. The speed and accuracy of sequential movements will be used as a measure of performance. These measures will be performed prior to training, immediately after, 48 hours, 7 days, and 28 days after trained hand training (TH) for assessment of short and long term learning. In addition, performance evaluations (1) of the reverse-trained sequence in TH will be performed to evaluate the generalization; (2) of the trained sequence in left hand (non-trained) to evaluate the intermanual transfer; and (3) trained sequence in TH in double-task condition to evaluate automaticity. Appropriate statistical methods will be used to identify inter- and intra-group differences.

Official Title
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Influence of Transcranial Direct Stimulation Current on Motor Learning of Young Adults

Conditions
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Healthy

Intervention / Treatment
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* Device: Transcranial Direct Current Stimulation
* Other: Simulated


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Young subjects aged between 18 and 35 years, right-hand (evaluated by the Edinburgh Inventory), of both genders, attending the third grade in a private university. Exclusion Criteria: Individuals using central nervous system drugs with uncorrected visual and / or auditory disorders who have any neurological, psychiatric, or orthopedic diseases and who have differentiated finger, musician or typist skills will be excluded. Due to the electrostimulation procedure, individuals who use hair chemistry, individuals who have a metallic implant on the head or a pacemaker, and who have scars in the region to be stimulated will also be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transcranial Direct Current Stimulation<br>Intervention: anodic tDCS (20 minutes ON, intensity 2milliamps) on the primary motor cortex contralateral of the trained hand (right) simultaneously to the motor training and supraorbital cathode ipsilateral Motor training will consist of 8 blocks with 300 repetitions of sequential finger movements performed with the right hand. | Device: Transcranial Direct Current Stimulation<br>* Anodic tDCS during 20 minutes ON, intensity 2milliamps, on the contralateral motor cortex of the trained hand simultaneously with the motor training. The cathode (negative electrode) will be positioned over the contralateral supraorbital region. It wil be used rubber electrodes covered by a vegetal electrode embedded in saline solution, physiological saline, measuring 5 x 5 cm (25 cm2).<br>|
| Sham Comparator: Control<br>Intervention: simulated anodic tDCS (30 seconds ON, intensity 2milliamps) on the primary motor cortex contralateral of the trained hand (right) simultaneously to the motor training and supraorbital cathode ipsilateral Motor training will consist of 8 blocks with 300 repetitions of sequential finger movements performed with the right hand. | Other: Simulated<br>* Simulated anodic tDCS (only 30 seconds ON), intensity 2milliamps, on the contralateral motor cortex of the trained hand simultaneously with the motor training. The cathode (negative electrode) will be positioned over the contralateral supraorbital region. It wil be used rubber electrodes covered by a vegetal electrode embedded in saline solution, physiological saline, measuring 5 x 5 cm (25 cm2).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speed | The speed (number of repetitions in a minute) of sequential movements will be used as a measure of performance. These measures will be performed prior to training, immediately after, 48 hours, 7 days, and 28 days after trained hand training (TH) for assessment of short and long term learning. In addition, performance evaluations (1) of the reverse-trained sequence in TH will be performed to evaluate the generalization; (2) of the trained sequence in left hand (non-trained) to evaluate the intermanual transfer; and (3) trained sequence in TH in double-task condition to evaluate automaticity. | Up to 28 days | 
| Accuracy | The accuracy (number of errors in a minute) in the same way as described to Outcome 1 | Up to 28 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Learning, Automatism, Motor Activity, Electric Stimulation