Brain Stimulation and Cognitive Training in Healthy Older Adults

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

Detailed Description
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The goal of the present study is to assess behavioral (primary) and neural effects of a multi-session cognitive training combined with transcranial direct current stimulation (tDCS). Many studies to date have found tDCS to be an efficient method to enhance various cognitive functions by modulating cortical excitability in young adults, but its behavioral impact and underlying mechanisms in aging still need to be elucidated. Healthy older adults will participate in a three-week cognitive training with concurrent online tDCS application. Cognitive performance (primary), as well as structural and functional imaging data will be examined before, during and after the intervention. In order to draw conclusions about the effect of tDCS in addition to cognitive training, a control group, receiving sham stimulation during training, will be assessed. Furthermore, to assess neural correlates of performance improvement, functional and structural parameters will be measured with MRI before and after training. Follow-up sessions to assess long-term effects are planned four weeks and six months after the post assessment. The results of the study will offer valuable insights into efficacy of combined tDCS and cognitive training, as compared to training alone, in older adults. Moreover, improved understanding of tDCS effects on cognitive training performance and underlying neural correlates may help to develop novel approaches for cognitive decline in healthy and pathological aging.

Official Title
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tDCS-accompanied Cognitive Training Effects in Healthy Older Adults - Randomised, Sham Controlled, Interventional Study

Conditions
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Aging

Intervention / Treatment
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* Device: Anodal tDCS
* Behavioral: Intensive cognitive training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Older adults (65 - 80 years); Right handedness; Unobtrusive neuropsychological screening Exclusion Criteria: Mild cognitive impairment (MCI) or dementia; other neurodegenerative neurological disorders; epilepsy; previous stroke; Severe and untreated medical conditions that precludes participation in the training, as determined by responsible physician; History of severe alcoholism or use of drugs; Severe psychiatric disorders such as depression (if not in remission) or psychosis; 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: 65 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: stimulation group<br>Anodal tDCS + intensive cognitive Training | Device: Anodal tDCS<br>* Anodal transcranial direct current stimulation (tDCS), 9 sessions with 20 minutes stimulation each (current intensity of 1mA)<br>Behavioral: Intensive cognitive training<br>* Intensive cognitive training of a letter memory updating task and a 3-stage Markov decision making task, 9 sessions<br>|
| Sham Comparator: sham group<br>Sham tDCS + intensive cognitive Training | Behavioral: Intensive cognitive training<br>* Intensive cognitive training of a letter memory updating task and a 3-stage Markov decision making task, 9 sessions<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Working memory training performance (Letter Updating task) | Performance in a memory training task (Letter updating) under anodal tDCS compared to sham condition;operationalized by working Memory Updating performance assessed with number of correctly recalled letter lists in the letter updating task, analyzed immediately after training period (anodal condition versus sham) | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Working memory training performance (Markov task) | Performance in second memory training task (Markov decision making) under anodal tDCS compared to sham condition, analyzed immediately after training period (anodal condition versus sham) | 3 weeks | 
| Transfer outcomes | Performance in cognitive transfer tasks, comparing performance immediately before and after training period (anodal condition versus sham) | 3 weeks | 
| Long-term outcomes | Long-term performance in training and transfer tasks, comparing performance immediately before and after training period with performance at 4 weeks and 6-months after training period (anodal condition versus sham) | 4 weeks after training, 6 months after 4-week follow-up | 
| Neural correlates | Structural and functional neural correlates of the intervention, as measured by structural, functional resting-state and diffusion weighted MRI, immediately before and after the intervention and 6 months after follow-up (anodal condition versus sham) | 3 weeks, 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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memory, brain stimulation