The vestibulo-ocular reflex (VOR) stabilizes the gaze during rapid head movements by inducing an eye rotation of equivalent amplitude but in the opposite direction to the head rotation. Normally, the ratio of eye rotation amplitude to head rotation, or VOR gain, is 1. Under some conditions such as growth or the use of corrective glasses, this gain is adapted to the new visuo-vestibular conditions. This well-known sensorimotor adaptation phenomenon can be achieved through the experimental creation of a conflict between vestibular and visual information.

Incremental velocity error (IVE) allows for a rapid adaption of the VOR at high speed by synchronously projecting a laser target that moves to create a progressively increasing visuo-vestibular conflict. However, this method does not correspond to the ecological conditions of VOR use, as the training is conducted in darkness and the visuo-vestibular conflict does not involve the entire visual scene.

Recreating this type of adaptation in a virtual reality environment could allow for adaptation with a visual stimulus involving the entire visual scene, thus more closely resembling the physiological conditions of VOR use. We hypothesize that a visual simulation of the entire scene would be more effective than an isolated target in VOR adaptation during high velocity head rotation.

Inclusion Criteria:

• Age from 18 to 60
• Understanding of the experimental instructions
• Informed Consent

Exclusion Criteria:

• Underlying ENT or neurological disorders
• Corrected Visual Acuity lower than 5/10
• Other conditions leading to oscillopsia or ataxia
• Oculomotor palsy, ocular instability in primary position
• Treatment that may affect ocular motility (psychotropes)
• Cervical rachis pathology with instability
• Cochlear Implants
• Non-stabilized medical disease
• Subject suffering from debilitating motion sickness or Virtual Reality sickness
• Pregnant women
• Patients under tutelage
• Patient without social security

healthy subjects