Transfer Effects of Combined Attentional Filter Exercise and Transcranial Direct Current Stimulation

Study Overview
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Brief Summary
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Investigation of how a single session of an attentional filter exercise of distractor inhibition combined with tDCS modulates cognitive functions like working memory, decision making and attentional control.

Detailed Description
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The study is designed as a between subject design with two groups defined by real or sham tDCS. The distractor inhibition exercise is conducted under either sham or real tDCS. Cognitive performance is assessed pre and post tDCS application, complemented by a short-termed follow-up on a consecutive day. Interindividual working memory capacity at baseline is taken into consideration.

Official Title
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Cognitive Transfer Effects on Working Memory and Higher Cognitive Functions by Combined Attentional Filter Exercise and tDCS in Healthy Younger Adults

Conditions
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Healthy

Intervention / Treatment
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* Device: transcranial direct current stimulation (tDCS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: right-handed aged between 18 and 30 years normal or corrected to normal vision German-speaking Exclusion Criteria: dyschromatopsia neurological or neuropsychiatric diseases low seizure threshold neurological medication metal implants in the head

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: tDCS group<br>one session of computerized change detection attentional filter exercise (selective attention) combined with real tDCS | Device: transcranial direct current stimulation (tDCS)<br>* sham or real tDCS for 10 minutes of 1.5 milliampere (mA) tDCS targeting the prefrontal and the posterior parietal cortex<br>|
| Sham Comparator: sham group<br>one session of computerized change detection attentional filter exercise (selective attention) combined with sham tDCS | Device: transcranial direct current stimulation (tDCS)<br>* sham or real tDCS for 10 minutes of 1.5 milliampere (mA) tDCS targeting the prefrontal and the posterior parietal cortex<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Performance change in computerized attentional filter exercise | attentional filtering performance (in % correct), effects of distractor interference for different set sizes | 45 minutes on 1st day (pre) and on consecutive day (post) | 
| Reaction change in computerized attentional filter exercise | reaction times (in milliseconds), effects of distractor interference for different set sizes | 45 minutes on 1st day (pre) and on consecutive day (post) | 
| Performance change in working memory and filtering performance | Working memory and filtering performance (in % correct), effects of distractor interference for different set sizes | 30 minutes per pre-assessment, post assessment directly after intervention and short-termed follow-up on the consecutive day | 
| Reaction change in working memory and filtering performance | reaction times (in milliseconds), effects of distractor interference for different set sizes | 30 minutes per pre-assessment, post assessment directly after intervention and short-termed follow-up on the consecutive day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spatial Span | computerized spatial span forward and backward | 10 minutes per pre-assessment and short-termed follow-up on the consecutive day | 
| Iowa Gambling Task | Decision making performance | 7 minutes per pre-assessment, post assessment directly after intervention and short-termed follow-up on the consecutive day | 
| Trait-Anxiety | Assessment of trait anxiety via State-Trait-Anxiety-Inventory on first day | 2 minutes on first day | 
| State-Anxiety | Daily assessment of state anxiety via State-Trait-Anxiety-Inventory at the beginning of each testing day | 2 minutes on first and consecutive day | 
| Assessment of Sleep Quality | daily questionnaire assessing subjective rating of sleep of the previous night on 5- to 7-point Likert format and open questions (subjective quality of sleep, current fatigue, duration of sleep); no total score | 10 minutes on first and consecutive day | 
| Daily Performance Questionnaires | self developed questionnaire assessing subjective performance in tested paradigms (5-point Likert format); no total or sub score; Question 1: How difficult would you rate the task? (lowest (1) = very difficult; highest (5) = very easy) Question 2: Do you think your performance changed in the course of the task? (lowest (1) = strongly worsened; highest (5) = strongly improved) | 5 minutes on first and consecutive day | 
| Daily Strategy Questionnaires | reporting of used strategies in tested paradigms (open questions; subjects reported in written notes); self developed questionnaire for qualitative analyses of task demands; no scores; Question: Did you use a strategy? If so, please explain shortly. | 5 minutes on first and consecutive day |