Determining the Specificity of High Definition Electrical Brain Stimulation Using Simultaneous Magnetoencephalography

Study Overview
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Brief Summary
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Non-invasive human brain stimulation using weak transcranial direct-current stimulation (tDCS) has been thousands of times in research studies over the past fifteen years as a therapy to help improve the effectiveness of repeated training sessions (e.g., hand exercises in the context of daily physiotherapy), due to its safety, tolerability, convenience and cost-effectiveness. tDCS works by temporarily enhancing brain activity during performance of a specific task, helping with learning and training. The investigators will use magnetoencephalography (MEG) brain imaging to view the real-time effects of high definition (HD) tDCS on several brain areas involved in vision, hearing, movement, and memory. The investigators hypothesize that changing the task (auditory, visual or memory task) but keeping the position of the electrodes over the motor cortex will result in modulation of brain activity in only the central target motor area, and not on non-target temporal, occipital or pre-frontal areas.

Official Title
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Measuring the Stimulated Brain: Determining the Specificity of High Definition Electrical Brain Stimulation Using Simultaneous Magnetoencephalography

Conditions
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Real HD-tDCS, Sham HD-tDCS, Visual Task, Motor Task, Auditory Task, Working Memory Task

Intervention / Treatment
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* Device: HD-tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Normal hearing and vision Exclusion Criteria: Current pregnancy Presence of metallic implants in the head Use of any medications Any history of mental health or neurological conditions Inability to perform any of the tasks for any reason

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Real HD-tDCS first, Sham HD-tDCS second<br>Real HD-tDCS will be applied in the first session Sham HD-tDCS will be applied in the second session (at least one week after the first session) | Device: HD-tDCS<br>* HD-tDCS non-invasive brain stimulation using this same device (Soterix) has been designated a 'non-significant risk' by the US FDA.<br>* Other names: High Definition Transcranial Direct Current Stimulation;|
| Other: Sham HD-tDCS first, Real HD-tDCS second<br>Sham HD-tDCS will be applied in the first session Real HD-tDCS will be applied in the second session (at least one week after the first session) | Device: HD-tDCS<br>* HD-tDCS non-invasive brain stimulation using this same device (Soterix) has been designated a 'non-significant risk' by the US FDA.<br>* Other names: High Definition Transcranial Direct Current Stimulation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in brain activity | Assessment of changes in brain activity will be done using both event-related and frequency domain beam former localization. | Immediate (20 minutes) |