Verticality Perception - Multisensory Contribution

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the relative contribution of head- and trunk-based sensory systems to internal estimates of direction of gravity in healthy human subjects. To implement this assessment experimentally, the investigators will use a motor-driven 3D-turntable and a thermoplastic mask to keep the head in a stable, either roll-tilted (±30°) or aligned with the trunk. The investigators will then obtain measurements of the subjective visual vertical in seven different whole-body roll positions (max. 90° roll-tilt). Analysis will be driven by a state-of-the art Bayesian integration model. The investigators hypothesize that different sensory input signals are combined in a statistically optimal fashion.

Official Title
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Verticality Perception - Dissociating Head and Trunk Contributors in Healthy Human Subjects

Conditions
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Verticality Perception in Healthy Human Subjects, Individual Contribution of Different Sensory Systems

Intervention / Treatment
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* Other: Vestibular stimulation by use of the turntable (static roll-tilt while the head is roll-tilted relative to the trunk)
* Other: 3D-video-head impulse testing
* Other: Vestibular-evoked myogenic potentials (VEMPs)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ages 18-60 years informed consent absence of exclusion criteria Exclusion Criteria: peripheral-vestibular deficit disturbed consciousness history of sensory deficits visual field deficits other neurological or systemic disorder which can cause dementia or cognitive dysfunction intake of antidepressants, sedatives, or neuroleptics pregnancy, unless excluded by a negative pregnancy test known neck pain or status post neck trauma

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Vestibular stimulation<br>This is the experimental paradigm applied in all participants | Other: Vestibular stimulation by use of the turntable (static roll-tilt while the head is roll-tilted relative to the trunk)<br> <br> Other: 3D-video-head impulse testing<br>* Evaluation of semicircular canal function. This intervention is part of the screening to determine suitability for this study<br>Other: Vestibular-evoked myogenic potentials (VEMPs)<br>* Evaluation of otolith function. This intervention is part of the screening to determine suitability for this study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy and precision of SVV adjustments in different head and trunk roll-tilt positions |  | During the turntable measurement (90 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| relative contribution of head- and trunk-based sensory systems based on Bayesian modelling |  | while on the turntable (1.5 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vestibular, proprioception, spatial orientation, bayesian