Cybersickness imAgiNg Olfactory Evocation

Study Overview
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Brief Summary
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The aim of this study is to, using fMRI, compare brain activations during olfactory imagery induced by different visual supports (words, pictures, colors and colored arrangements) in healthy subjects. This will allow us to choose the best olfactory imagery facilitator and to assess its effect on cybersickness.

Official Title
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Cybersickness imAgiNg Olfactory Evocation

Conditions
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Healthy

Intervention / Treatment
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* Device: Functional MRI
* Other: Virtual Reality: control
* Other: Virtual Reality: experimental


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: to be of French nationality who has always lived in metropolitan France; to be right-handed person; to be enrolled in a social security plan; to be able to understand the instructions given; to have underwent a pre-inclusion medical examination; to give a written consent; Person with a strong capacity for olfactory imagination: having obtained a score strictly below 2.5 on the fVOIQ olfactory imagination questionnaire. Exclusion Criteria: to have an inability to read French; to be recognized as a synesthete; to have a professional activity requires intense olfactory activity; to have a partial or total loss of smell (hyposmia, anosmia); to have qualitative smell disorders (carcosomia, hyperosmia, phantosmia, parosmia); to have smell disorders of neurological, post-traumatic or neurodegenerative origin; to have uncorrected or poorly corrected visual disturbances; to have vestibular disorder diagnosed; any contraindication to MR examination (active medical device, ferromagnetic foreign body, pregnancy, morbid obesity, claustrophobia, … ); subject under a measure of legal protection.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental<br> | Device: Functional MRI<br>* The volunteer will have to imagine the smells evoked by different visual aids. This task will be carried out during 2 acquisition runs of about 10 minutes each. The volunteer should note (on a scale from 1 to 4) the pleasantness of the smell evoked.<br>* Other names: fMRI;Other: Virtual Reality: control<br>* The volunteer will be immersed in a virtual maritime environment with nauseating characteristics. In the center of the maritime scene, it will be visible the black outlines of a frame. Every minute, the volunteer will be asked to verbalize the level of his general condition via the Fast Motion Sickness Scale (1 to 20).<br>* Other names: VR control;Other: Virtual Reality: experimental<br>* The volunteer will be immersed in a virtual maritime environment with nauseating characteristics. The visual support inserted in the center of the virtual scene will be the one defined as being the most facilitator of the olfactory imagination during the fMRI examination. The volunteer will be asked to concentrate on the smell evoked by this support. Every minute, the volunteer will be asked to verbalize the level of his general condition via the Fast Motion Sickness Scale (1 to 20).<br>* Other names: VR experimental;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of cerebral activations between the different supports mediating the olfactory imagination during the execution of the fMRI tasks. | The cerebral activations between the different supports mediating the olfactory imagination will be compared in terms of localization and intensity of the variations of the BOLD signal during the execution of the fMRI tasks. | Baseline (J0) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determination of the visual support allowing the strongest olfactory imagination during the fMRI by subjective evaluations using two 4-level Likert scales. | Subjective evaluations will be carried out using two 4-level Likert scales. | Baseline (J0) | 
| Determination of the visual support allowing the strongest olfactory imagination during the fMRI test by the cerebral activations in areas recognized for their implications in the olfactory imagination. | The cerebral activations will be measured by the intensity of the variations of the BOLD signal during the execution of the fMRI tasks. | Baseline (J0) | 
| Description of the evolution of the cardiac activity during olfactory imagination tasks in fMRI. | The cardiac activity will be evaluated by the R-wave interval. The cardiac activity will be recorded via the ECG during olfactory imagination tasks in fMRI. | Baseline (J0) | 
| Description of the evolution of the respiratory activity during olfactory imagination tasks in fMRI. | The respiratory activity will be evaluated by the respiratory rate. The respiratory activity will be recorded via the respiratory belt during olfactory imagination tasks in fMRI. | Baseline (J0) | 
| Evaluation of the state of discomfort in virtual reality by measuring the cardiac activity. | Cardiac activity will be evaluated by the R-wave interval. Cardiac activity during immersion will be recorded by the cardio-respiratory belt. | Baseline (J0) and 6 months maximum after J0 (V1) | 
| Evaluation of the state of discomfort in virtual reality by the Simulator Sickness Questionnaire (SSQ) before and after immersion. | The participant will answer to the Simulator Sickness Questionnaire (SSQ) before and after immersion (minimum=0 and maximum=235,62). A higher score means a more severe discomfort. | Baseline (J0) and 6 months maximum after J0 (V1) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fMRI