Neuromodulation by Non-invasive Brain Stimulation

Study Overview
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Brief Summary
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The main objective of this study is to estimate the effect of the neuromodulation on the behavioral performances during the access in semantics according to the age of the individuals. Neuromodulation by non-invasive stimulation allows to explore the functioning of the brain by exciting or by inhibiting localized cortical zones. The modulation of the performances in cognitive tasks, further to the neuromodulation of these zones, allows to deduce on their functional roles.

Detailed Description
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The objective of this project is to determine the changes of behavioral performances (time of answer, percentage of correct answers) further to the neuromodulation. The specific question is to estimate the effect on the performances of access at the semantic representations of this method, according to the age. One of the hypotheses in the research on the normal ageing is the difficulty of access to these representations (fundamental process for the cognitive functions, such as the language and the memory) at the healthy elderly. By using the neuromodulation the investigators wish to explore this hypothesis and to understand if the neuromodulation can have a beneficial effect on the improvement of the behavioral performances of the elderly.

Official Title
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Neuromodulation by Non-invasive Brain Stimulation (NEUROMOD)

Conditions
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Healthy, Transcranial Magnetic Stimulation, Transcranial Direct Current Stimulation

Intervention / Treatment
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* Other: MRI + transcranial Magnetic Stimulation
* Other: transcranial electric stimulation + electroencephalogram


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Major healthy Subject ( 18 - 85 years) Right-hander Signed Informed consent A medical examination must be made before the participation for the research Membership in or beneficiary of a national insurance scheme Non inclusion Criteria: Subject under age 18 and of more than 85 years. Contraindications in the practice of MRI, TMS and tES Existence of a severe affection on the general plan: cardiac, respiratory, hematological, renal, hepatic, cancerous Regular taking of anxiolytic, sedative, antidepressant, neuroleptic Characterized psychiatric pathology Ingestion of alcohol before the examination Pregnancy, parturiency or breast-feeding Private person of freedom by court or administrative order, nobody being the object of a legal protective measure (under guardianship or guardianship) Participation to other protocols of current search with period of exclusion or in the previous week Subject which would perceive more than 4500 euros of compensation because of its participation in other searches involving the human person in 12 months preceding this study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: outcoume measure comparison is done between both age groups (18-49 years and 50-85 years).
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 18-49 years group<br>Participants undergo 2 sessions of MRI + transcranial Magnetic Stimulation or transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days. | Other: MRI + transcranial Magnetic Stimulation<br>* Healthy subjects undergo 2 sessions of MRI + transcranial Magnetic Stimulation + transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days.<br>Other: transcranial electric stimulation + electroencephalogram<br>* Healthy subjects undergo 2 sessions of MRI + transcranial Magnetic Stimulation + transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days.<br>|
| Experimental: 50-85 years group<br>Participants undergo 2 sessions of MRI + transcranial Magnetic Stimulation or transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days. | Other: MRI + transcranial Magnetic Stimulation<br>* Healthy subjects undergo 2 sessions of MRI + transcranial Magnetic Stimulation + transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days.<br>Other: transcranial electric stimulation + electroencephalogram<br>* Healthy subjects undergo 2 sessions of MRI + transcranial Magnetic Stimulation + transcranial electric stimulation + electroencephalogram. The 2 sessions are performed with an interval of 3 to 7 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of the neuromodulation on the behavioral performances during the access in semantics | Evaluation of the changes of the behavioral performances before and after the neuromodulation by non-invasive cortical stimulation according to the age. More exactly, the investigators shall compare response times before and after neuromodulation between both age groups (18-49 years and 50-85 years), by testing the interaction between the effect of the neuromodulation and the age. | 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Estimate the effect of the neuromodulation on the behavioral performances | Compare the percentages of correct answers before and after neuromodulation by non-invasive cortical electric stimulation, according to the age (18-49 years vs 50-85 years). | 3 hours | 
| Estimate the effect of transcranial Electrical Stimulation (tES) on the cognitive performances by neuropsychological scores, according to the age. | Comparison of the neuropsychological scores before and after tES, according to the age (18-49 years vs 50-85 years). | 3 hours | 
| Estimate the effect of tES on the cerebral functional activity, by comparing blood-oxygen-level dependent (BOLD ) signal or functional MRI before and after tES according to the age (18-49 years vs 50-85 years). | The investigators extract estimates parameters (Estimated Beta weight Values) corresponding to each tES stimulation. Each session is be designed by using general linear model (Friston, 1998, statistical parametrical mapping in fMRI) defined as Ybefore tES = R1Beta1+R2Beta2 +R0Beta0 + e and Yafter tES = R1Beta1 +R2Beta2 +R0Beta0 + e, with Y = acquired BOLD signal, e = error, R1Beta1 corresponding to the task (meaning interest activation) regressor and R2Beta2 corresponding to the control (meaning no interest activation) regressor respectively convolved with the canonical hemodynamic response function (cHRf) and R0B0 corresponding to the constant regressor. Parameter estimates are calculated by extracting Beta1 and Beta2 values for each session respectively in order to compute statistical comparison (measure by subject) on the outcome measure (Beta1 before tES - Beta1 after tES). | 3 hours | 
| Estimate the effect of the Transcranial Magnetic Stimulation (TMS) on the cognitive performances by neuropsychological scores, according to the age. | Comparison of the neuropsychological scores before and after Transcranial Magnetic Stimulation (TMS), according to the age (18-49 years vs 50-85 years). | 3 hours | 
| Estimate the effect of the TMS on the intellectual functional activity, according to the age. | Comparison of the cerebral functional activity (electric neuronal signal, EEG) before and after TMS, according to the age (18-49 years vs 50-85 years). | 3 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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non-invasive brain stimulation, neuromodulation, semantic tasks