Physiological Changes Exploration During the Hypnotic State

Study Overview
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Brief Summary
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Use of hypnosis for therapeutic purposes tends to spread. However, the neural mechanisms underlying hypnosis is still debated and no specific change has yet been associated with this state. In this context, it seems necessary to clarify its mechanisms and effects. Since hypnosis induces a change of consciousness state, the investigators hypothesize that this modification is accompanied by neural activity changes recordable with magnetoencephalography (MEG). The primary objective of this study is to identify neural activity changes during hypnotic trance in healthy volunteers.

Detailed Description
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Since the 19th century, the potential changes induced by hypnosis have been investigated. Indeed, hypnosis induces a change on the usual state of conscious awareness. This state is accompanied by physiological changes, as cardiac and cerebral. However, although literature on the neural mechanisms underlying hypnosis increases, no specific activity change has been identified. Only the subjective judgment of hypnotherapist can assume the volunteer state. Considering that the use of hypnosis enhanced in the field of medical care, it is necessary to clarify and define it. This requires a better understanding of its mechanisms through the study of brain, heart and respiratory activities. The aim of this clinical trial is to assess modifications of physiological signals (cardiac, respiratory and cerebral) before and during a session of hypnosis, to identify some biomarkers of the hypnotic trance. Therefore the cardiac, respiratory and cerebral activities will be recorded during hypnosis sessions and control state to compare the signals. The MEG will be used to record brain activity due to its sensitivity in the very low and high frequencies, its temporal resolution and its robustness for the localization of neural origins. In accordance with the literature and preliminary results, changes in theta oscillations (4-8 Hz) will be assessed. In fact, these oscillations seem to be increased during the hypnotic state. So, it seems interesting to correlate these oscillations with potential changes in heart and/or respiratory rhythms. This clinical trial is an open mono-centric study, performed on a cohort of healthy volunteers in which each subject is his own control (intra-subject control). The physiological parameters will be recorded and analyzed during three control states (subject alone, subject and hypnotherapist without communication and reading a book by the hypnotherapist), and several blocks of hypnosis interleaved with an attentional task (stroop). All the collected parameters in these different conditions will be compared.

Official Title
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Physiological Changes Exploration During the Hypnotic State (HYPNOTE)

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Behavioral: Hypnosis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers Right-handed Non-smoking Major participants Speaking fluent French No experience of hypnosis or other forms of meditation and relaxation Registered in the French social security scheme Signed informed consent Exclusion Criteria: Contraindication to Magnetoencephalography (MEG) and/or Magnetic resonance imaging (MRI) : implanted material, claustrophobia,… Treatment that may impact physiological measures (psychotropic, cardiovascular,…) All categories of protected persons (Pregnant or lactating women, persons subject to a legal protection measure, persons deprived of their liberty by judicial or administrative decision) Smokers Persons with personality disorders or addictions / narcotic use

Ages Eligible for Study
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Minimum Age: 18 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: Right-handed healthy volunteers<br>Magnetoencephalography (MEG) records | Behavioral: Hypnosis<br>* several blocks of hypnosis including entry into a hypnotic state (= induction), the hypnotic trance and the exit from hypnosis (= reassociation).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural activity changes recorded by magnetoencephalography (MEG) during hypnotic trance, in healthy volunteers. | Oscillatory activity will be recorded by magnetoencephalography (MEG) : power averages of oscillations (delta, theta, alpha, beta and gamma) and phase values recorded during hypnotic trance will be compared to control conditions. | 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural networks activity changes recorded by magnetoencephalography (MEG) during hypnotic trance, in healthy volunteers. | Power average (Grad : fT²/Hz MAG : fT²/cm².Hz) of neuronal sources and correlations of sources activity for the Default Model Network (DMN) will be compared between hypnosis trance and control conditions. | 2 hours | 
| Changes in auditory evoked magnetic fields (MAEF), recorded by magnetoencephalography (MEG) during hypnotic trance, in healthy volunteers. | Global averages of MAEF (Grad : fT/(cm.√Hz) MAG : fT/√Hz) will be compared between hypnosis trance and control conditions. | 2 hours | 
| Cardiac and respiratory changes in link to neural activity changes observed during the hypnotic trance | Variations in heart rate and respiratory parameters (Hz) with neural activity changes previously described (ie: oscillatory activity, network activities (Grad : fT²/Hz MAG : fT²/cm².Hz) and MAEF (Grad : fT/(cm.√Hz) MAG : fT/√Hz)), will be compared between hypnosis trance and control conditions | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypnosis, MEG, Auditory Evoked Magnetic Fields, Oscillatory activity, Networks