Cognitive Training Combined With Transcranial Direct Current Stimulation in Older Adults in a Home-based Context

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 is feasible as a home-based intervention.

Detailed Description
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The goal of the present study is to assess feasibility (primary) and cognitive training and transfer effects of a home-based multi-session cognitive training combined with transcranial direct current stimulation (tDCS). tDCS, particularly in combination with cognitive training, represents a promising approach to counteract cognitive decline and restore impaired functions. However, combined interventions of cognitive training and tDCS involve frequent visits to the facility, which leads to the need of space, time and personnel, and imposes strains on the participants. This study will elucidate the feasibility of tDCS and cognitive training in a home-based context. Healthy older adults will participate in a two-week cognitive training with concurrent online tDCS application in their own homes. Feasibility, as well as cognitive performance 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. A Follow-up session to assess long-term effects is planned four weeks after the post assessment. We hypothesize that with appropriate training of the participants and close supervision the use of combined tDCS and cognitive training in an ecologically valid environment by the participants themselves is feasible. In addition, we hypothesize this protocol will lead to improved performance on the trained tasks in both experimental groups. We expect increased performance on transfer tasks and long-term maintenance of the effects after anodal compared to sham stimulation. A successful implementation of the intervention in the home-based setting will contribute to the development of home-based tDCS as a widely available therapy option in clinical populations.

Official Title
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Feasibility of Cognitive Training in Combination With Transcranial Direct Current Stimulation in a Home-based Context

Conditions
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Aging

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


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 60 - 80 years Right handedness Exclusion Criteria: Neurodegenerative neurological illnesses, epilepsy or history of seizures Severe and untreated medical conditions that preclude 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 to tDCS application

Ages Eligible for Study
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Minimum Age: 60 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: Double


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), 6 sessions with 20 minutes stimulation each (1,5 mA).<br>Behavioral: Intensive cognitive training<br>* Intensive cognitive training of a letter memory updating task, 6 sessions for approximately 20 min<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, 6 sessions for approximately 20 min<br>Device: Sham tDCS<br>* Sham transcranial direct current stimulation (tDCS), 6 sessions with 30 sec stimulation each (1,5 mA) to ensure blinding of participants.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility of conducting the intervention in a home-based context | Feasibility of home-based tDCS as operationalized by at least 2/3 (out of 6 planned sessions) successfully performed interventional sessions per participant. A session is regarded as successful if it is marked as completed in the stimulation system. | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility (questionnaire) | Self-rate questionnaire of participant satisfaction, independence and self-confidence in the handling of the devices and program (cf. Cha at el., 2016) after training period (anodal condition versus sham) | 2 weeks | 
| Working memory performance at post-assessment | Performance in a near transfer task (n-back) under anodal tDCS compared to sham condition; operationalized by % correct responses in the n-back task | 2 weeks | 
| Working memory performance at follow-up assessment | Performance in a near transfer task (n-back) under anodal tDCS compared to sham condition; operationalized by % correct responses in the n-back task | 4 weeks after intervention | 
| Working memory training performance (Letter Updating Task) at post-assessment | Performance in primary memory training task (Letter Updating Task) at post-assessment, operationalized by number of correctly recalled lists in the letter updating task | 2 weeks | 
| Working memory training performance (Letter Updating Task) at follow-up assessment | Performance in primary memory training task (Letter Updating Task) at follow-up assessment, operationalized by number of correctly recalled lists in the letter updating task | 4 weeks after intervention |