tDCS Effects on Associative Learning in Older Adults of Retirement Age

Study Overview
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Brief Summary
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The aim of this study is to investigate whether a tDCS-accompanied training of audio-visual associative memory leads to a performance improvement in healthy older individuals.

Official Title
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Effects of Transcranial Direct Current Stimulation (tDCS) on Associative Learning in Older Adults

Conditions
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Healthy Older Adults

Intervention / Treatment
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* Device: tDCS
* Behavioral: training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: old-retired (≥66 years). Right handedness unobtrusive neuropsychological screening Exclusion Criteria: Mild cognitive impairment (MCI) or other neurological diseases. History of severe alcoholism or use of drugs. Severe psychiatric disorders such as depression, psychosis (if not in remission) and severe untreated medical problems. Contraindication for MRI (claustrophobia, metallic implants, ferromagnetic metals in the body, disorders of thermoregulation, pregnant women)

Ages Eligible for Study
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Minimum Age: 66 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Anodal tDCS + training<br>Combination of intensive training of picture-word associations (Wernicko task) with anodal stimulation | Device: tDCS<br> <br> Behavioral: training<br> <br> * Other names: intensive training of picture-word associations;|
| Sham Comparator: Sham tDCS + training<br>Combination of intensive training of picture-word associations (Wernicko task) with sham stimulation | Device: tDCS<br> <br> Behavioral: training<br> <br> * Other names: intensive training of picture-word associations;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Performance in a verbal associative learning paradigm under anodal tDCS compared to sham tDCS. | Investigation whether anodal tDCS leads to improved performance accuracy in the Wernicko task compared to sham stimulation. | Performance is assessed within 1 day immediately after training period (several learning blocks) compared to sham | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional connectivity predictors | Connectivity as measured by resting-state fMRI during baseline as predictors for performance and tDCS responsiveness | assessed during baseline testing | 
| Structural predictors | Microstructure of white matter (Fractional Anisotropy) as measured by diffusion tensor imaging during baseline as predictors for performance and tDCS responsiveness | assessed during baseline testing | 
| Genotyping of learning related polymorphisms | To assess predictors of positive reaction to brain stimulation, genotyping of several learning related polymorphisms will be performed. | assessed during baseline screening | 
| Other cognitive outcomes: Attention performance | Digit span forward performance assessed before and after stimulation to test for tDCS effects on attention | Performance is assessed within 1 day before and after tDCS + training compared to sham | 
| Other cognitive outcomes: working memory | Digit span backwards performance assessed before and after stimulation to test for tDCS effects on working memory | Performance is assessed within 1 day before and after tDCS + training compared to sham | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS effects, associative learning