Effect of High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Attentional Control: an fMRI Study on Healthy Participants

Study Overview
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Brief Summary
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In a randomized, triple-blind, sham-controlled clinical trial, we will assess the effect of a single session frontal cortex High-Definition transcranial Direct Current Stimulation (HD-tDCS) on brain activity and functional connectivity underlying the behavioral change in attentional control in healthy participants. Participants will be recruited after meeting the inclusion criteria and will be randomly assigned to active or sham stimulation groups. All participants will undergo resting-state functional Magnetic Resonance Imaging (rsfMRI) scan and perform an Attention Network Test (ANT) in a functional Magnetic Resonance Imaging (fMRI) scanner before and after receiving a single session of active or sham HD-tDCS.

Official Title
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Effect of High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Attentional Control: an fMRI Study on Healthy Participants

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Device: Active High-Definition Transcranial Direct Current Stimulation (HD-tDCS)
* Device: Sham High-Definition Transcranial Direct Current Stimulation (HD-tDCS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Right-handed healthy adults Age range 20-39 years Normal or corrected-to-normal vision Willing and capable of following study protocol requirements given in the informed consent Exclusion Criteria: Psychiatric conditions (e.g., depression and generalized anxiety disorder, etc.) Medical illness or neurological disorder (e.g., cardiovascular illness, anemia, respiratory illness, neurological illness, seizure, etc.) Current abuse of drugs or alcohol Any conditions that prevent undergoing an fMRI scan or tDCS stimulation according to the fMRI and tDCS safety checklists

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 39 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: Parallel Assignment
Interventional Model Description: Participants are allocated to one of two conditions: Active or Sham.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active HD-tDCS<br>Participants in the active arm will receive 20 min of real High-Definition transcranial direct current stimulation. Additional ramp-up and ramp-down phases at the beginning and the end of stimulation will last for 30 s. | Device: Active High-Definition Transcranial Direct Current Stimulation (HD-tDCS)<br>* Portable multi-channel tES stimulation (Starstim 8, Neuroelectric, Barcelona, Spain) will be used.<br>|
| Experimental: Sham HD-tDCS<br>During the sham session, the montage will be identical, however, the current amplitude will ramp up for 30 seconds, and for the remaining stimulation time, the current flow will terminate and will be kept to zero. Ramp-down phase at the end of stimulation will last for 30 s. | Device: Sham High-Definition Transcranial Direct Current Stimulation (HD-tDCS)<br>* Portable multi-channel tES stimulation (Starstim 8, Neuroelectric, Barcelona, Spain) will be used.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Attention Network Test (ANT) performance before and after the intervention (active versus sham HD-tDCS) |  | Immediate before and immediate after intervention | 
| Change in resting state functional connectivity before and after the intervention (active versus sham HD-tDCS) |  | Immediate before and immediate after intervention | 
| Change in task-based functional connectivity during Attention Network Test (ANT) before and after the intervention (active versus sham HD-tDCS) |  | Immediate before and immediate after intervention | 
| Change in the blood-oxygen-level-dependent (BOLD) signal during Attention Network Test (ANT) before and after the intervention (active versus sham HD-tDCS) |  | Immediate before and immediate after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Side effect checklist for transcranial Direct Current Stimulation (Reported as Yes or No) |  | One day after simulation session | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Attention Network Test, High-Definition Transcranial Direct Current Stimulation, HD-tDCS, functional Magnetic Resonance Imaging, Attentional control