The Effect of Transcranial Direct Current Stimulation on Visual Attention - Single Sessions

Study Overview
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Brief Summary
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Recently, attention has been drawn to non-invasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), in order to enhance cognitive functions by modifying brain plasticity and use it in different healthy and diseased populations. In the current research, investigator aim to examine the short-term effects of multiple tDCS protocols in healthy adults population on visual attention and identify the neural underpinnings of tDCS-induced behavioral aftereffects using a combined tDCS/ MRI network-based approach.

Detailed Description
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Investigator will investigate the shor-term effects of active tDCS as compared to a placebo stimulation on visual attention in the healthy seniors. A cross-over, randomized, placebo-controlled design will be used. Single tDCS sessions will be performed in 4 sessions over distinct brain areas with ongoing visual attention training. During the stimulation, investigator will use the visual matching task. MRI protocol consisting of T1 and resting state fMRI sequences will be acquired before and after every stimulation session in order to search for active vs. placebo tDCS-induced changes in brain activation and resting state functional connectivity and to identify neural correlates of behavioral changes.

Official Title
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The Effect of Transcranial Direct Current Stimulation on Visual Attention - a Combined MRI and Non-invasive Brain Stimulation Single Session Study

Conditions
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Healthy Aging, Cognitive Change, Cognitive Decline

Intervention / Treatment
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* Device: Transcranial direct current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: right handed, healthy volunteers in two groups - healthy adults under 40 years, healthy seniors over 50 years Exclusion Criteria: psychiatric disorders, including major depression, major vascular lesions, and other brain pathologies detected by MRI that might present with cognitive decline a cardio pacemaker or any MRI-incompatible metal in the body epilepsy any diagnosed psychiatric disorder alcohol/drug abuse lack of cooperation presence of cognitive impairment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Real transcranial direct current stimulation<br>Healthy adults and healthy seniors will undergo application of real transcranial direct current stimulation over two distinct brain areas. | Device: Transcranial direct current stimulation<br>* 2mA stimulation for 20 minutes<br>|
| Experimental: Sham transcranial direct current stimulation<br>Healthy adults and healthy seniors will undergo application of sham transcranial direct current stimulation over two distinct brain areas. | Device: Transcranial direct current stimulation<br>* 2mA stimulation for 20 minutes<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual-attention task accuracy | Task will be presented on a computer and subject will respond by YES-NO buttons. Only if there are no differences in task accuracy, we will measure task reaction times (e.g. due to the roof effect). | Change from baseline immediately after completion of stimulation protocol | 
| Magnetic resonance imaging | Investigator will record high resolution structural T1-weighted (MPRAGE) images, functional T2* weighted multiband EPI sequences. The total time spent in the scanner will be approximately 40 in every session. | Change from baseline immediately after completion of stimulation protocol | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transcranial direct current stimulation, Healthy seniors, Healthy adults