Brain Network Mechanisms Causally Underlying Human Decisions Revealed by Brain Stimulation and Functional MRI

Study Overview
=================
Brief Summary
-----------------
We will examine how stimulation of specific brain areas with transcranial magnetic stimulation (TMS) or transcranial electric stimulation (tES) changes specific aspects of behavior and brain activity, in order to test hypotheses about brain behavior relationships (basic research).

Official Title
-----------------
Brain Network Mechanisms Causally Underlying Human Decisions Revealed by Brain Stimulation and Functional MRI

Conditions
-----------------
Behavior and Behavior Mechanisms

Intervention / Treatment
-----------------
* Other: TMS or tES
* Other: sham TMS or tES


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: between 18 and 80 years of age (whereby for most studies the majority of recruited participants will be between 18 and 40 years of age) right-handedness and/or one specific gender (male or female) can be inclusion criteria to reduce variation in the data. Exclusion Criteria: inability to understand the instructions and insufficient knowledge of the project language Internal electronic and/or metallic objects in the head, neck, or shoulders (e.g. artificial cochleae, deep brain stimulators, medical pumps, shrapnel, metallic splinters due to accidents during metal welding) One or more epileptic fits in the participant or a first-degree relative Vascular, traumatic, tumoral, infectious, or metabolic brain damage Use of medication that significantly alters cortical excitability Acute sleep deprivation or withdrawal from alcohol pregnancy to reduce bias, students of psychology or economics can be excluded if there is a possibility that they are familiar with the relevant paradigm.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Stimulation<br>TMS or tES, depending on experiment | Other: TMS or tES<br>* Transcranial magnetic or electric stimulation<br>|
| Sham Comparator: Sham<br>Corresponding sham TMS or tES | Other: sham TMS or tES<br>* Sham transcranial magnetic or electric stimulation<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speed of Behaviour | Reaction time in miliseconds | 0-60 minutes after stimulation | 
| Accuracy of Behaviour | Accuracy in percent correct | 0-60 minutes after stimulation | 
| Cognitive Function driving Behaviour | Parameter of Model describing cognitive function governing behaviour | 0-60 minutes after stimulation | 
| Brain activity | BOLD contrast in fMRI data | 0-60 minutes after stimulation |