Feedbacks' Influence on Decision Making Processes

Study Overview
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Brief Summary
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The purpose of this research is to identify and probe the neural networks involved in feedback processing. It aims at translating this knowledge to clinical populations in which this network is disrupted or compromised. It includes two studies: 1) with fMRI in healthy subjects to identify the neural bases of feedback processing on decision making using different types of feedback (neutral, social and monetary) presented either infra- or supra-laminary and 2) probing the role of one structure, the anterior cingulate cortex, using Galvanic Vestibular Stimulation (GVS) in healthy subjects. The interventional part consists in the administration of Galvanic Vestibular Stimulation (GVS), which by means of small intensity currents activates the vestibular organs and subsequently vestibular-related brain areas. GVS will be delivered to healthy participants engaged in behavioural tasks requiring the processing of feedbacks of different nature (e.g. social or monetary feedbacks)

Official Title
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Feedbacks' Influence on Decision Making Processes

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Other: mRI
* Other: Effect of Galvanic Vestibular Stimulation on decision making processes


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Benefit of social health security Normal or corrected-to-normal vision Exclusion Criteria: Anamnesis of neurological of psychiatric illness Pregnancy or breastfeeding Administrative measures restricting legal rights Epilepsy (including familiarity), migraines, chronic headaches presence of pacemakers, cochlear implants, surgical clips, or any metallic component fixed in participants' body Current treatment with psychotropic drugs Alcohol assumption during the last 24 hours Sleep deprivation Recent participation to other brain stimulation studies (< 1 week)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: healthy volunteers<br> | Other: mRI<br>* Neural bases of feedbacks' influence on decision making processes<br>Other: Effect of Galvanic Vestibular Stimulation on decision making processes<br>* Galvanic Vestibular Stimulation (GVS) stimulates the vestibular system through low intensity electric currents applied at the basis of the VIII cranial nerve, upon the mastoid processes. In the Right-Anodal condition the positive electric charge is applied through electrodes placed upon the right mastoid and it mainly activates structures within the left brain hemisphere. In the Left-Anodal condition the positive electric charge is applied through electrodes placed upon the left mastoid and it mainly activates structures within the right brain hemisphere. In the SHAM condition, low intensity electric currents are applied 5 cm below the mastoid processes. This condition does not activate the vestibular system and serves as a control condition to account for unspecific activating effects of all electric stimulations (e.g., arousal, discomfort). The three conditions will be applied in three different sessions (i.e. days) in randomized order.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral performance (Accuracy) | The proportion of correct responses, automatically computed by professional programs (e.g. Presentation) running on standard Personal Computers depending on different contexts (e.g. different feedback: neutral, social and monetary). | up to 4 days | 
| Behavioral performance (Reaction times) | The proportion of reaction times provided, automatically computed by professional programs (e.g. Presentation) running on standard Personal Computers depending on different contexts (e.g. different feedback: neutral, social and monetary). | up to 4 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural activity (BOLD signal measured using fMRI) as a function of the nature of the feedback. | Neural activity changes during learning of visuomotor associations in different contexts (e.g. different feedback: neutral, social and monetary) measured using Blood-oxygen-level dependent contrast imaging (BOLD). | up to 4 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Feedback Processing, functional Magnetic Resonance Imaging, Galvanic Vestibular Stimulation, Reward, Social, Vestibular System, Cingulate Cortex, Decision-making