Understanding the Neural Mechanisms Behind tDCS

Study Overview
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Brief Summary
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The aim of the study is to investigate the neural mechanisms underpinning transcranial direct current stimulation (tDCS), a non-invasive neuromodulation technique in which a direct current is passed through scalp electrodes. A series of experiments will be conducted to understand and characterize the transcranial and transcutaneous mechanisms of tDCS. To investigate this research question, every participant will undergo three stimulation conditions (active, sham and control). In the control condition, an anaesthetic cream will be applied to anaesthetize the nerves in the scalp. In addition, the effectiveness of tDCS and peripheral nerve stimulation will be compared. Ultimately, the obtained knowledge can lead to the development of improved non-invasive neuromodulation therapies, which can lead to more effective treatments of a variety of neurological and psychiatric disorders.

Official Title
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Understanding the Neural Mechanisms Behind Transcranial Direct Current Stimulation

Conditions
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tDCS Mechanisms

Intervention / Treatment
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* Device: brain stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: good general health Exclusion Criteria: Epilepsy or family history of epilepsy Migraine Allergic to lidocaine or benzocaine Pregnant History of or currently suffering from: neurological diseases psychiatric diseases, depression or anxiety (Annex B and Annex C) History of: brain surgery brain thrombosis cerebral hemorrhage severe head trauma meningitis long period of loss of consciousness (> 1 hour) Metal parts in the head or upper body: Defibrillator, implanted medication pump Metal prosthesis in ear, hart, … Deep brain stimulator Coronary bypass or intracranial or aneurysm clips (brain arteries, aorta, etc.)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: optimization of control anesthetic condition<br> | Device: brain stimulation<br>* tDCS and peripheral nerve stimulation<br>* Other names: skin intervention;|
| Experimental: understanding tDCS effect on motor learning<br> | Device: brain stimulation<br>* tDCS and peripheral nerve stimulation<br>* Other names: skin intervention;|
| Experimental: understanding tDCS effects on cortical excitability<br> | Device: brain stimulation<br>* tDCS and peripheral nerve stimulation<br>* Other names: skin intervention;|
| Experimental: optimizing peripheral nerve stimulation protocols<br> | Device: brain stimulation<br>* tDCS and peripheral nerve stimulation<br>* Other names: skin intervention;|
| Experimental: Effect peripheral nerve stimulation on motor learning<br> | Device: brain stimulation<br>* tDCS and peripheral nerve stimulation<br>* Other names: skin intervention;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analogue Scale | Rate sensation from 0 ('I feel nothing') to 10 ('Stimulation is painful') | 30 minutes during stimulation | 
| Reaction time | Reaction time on the motor learning task | 20 minutes during tDCS stimulation | 
| Reaction time | Reaction time on motor learning task | 20 minutes during peripheral nerve stimulation | 
| Amplitudes of event related potentials | ERP during stimulation | during tDCS | 
| Amplitudes of event related potentials | ERP during stimulation | during peripheral nerve stimulation | 
| Pupil dilations | pupil diameter during stimulation | during peripheral nerve stimulation |