Effects of Prolonged Roll-tilt in Healthy Human Subjects

University of Zurich (UZH)

Status: Unknown

Conditions: Adaptation Reaction

Treatments: Behavioral: presentation of visual and vestibular stimuli

Study type: Interventional

Funder types: Other

Identifiers

NCT02980419

post_tilt_study

Details and patient eligibility

About

The long-term goal of this research is to advance the investigators knowledge of how the brain combines the information of multiple sensory systems coding for spatial oriention and how adaptation to vestibular imbalance influences spatial orientation. In healthy human subjects verticality perception is accurate while upright. After prolonged roll-tilt, humans show a systematic bias in perceived direction towards the previous roll-tilted position (so-called "post-tilt bias"). This effect could either be related to adaptation to the roll-tilted position (shifting the "null" position) or it could be related to changes in torsional eye position due to prolonged static roll-tilt (ocular counter-roll). While in the first case a post-tilt bias is predicted independently of the experimental paradigm used, the second hypothesis predicts a post-tilt bias only if retinal cues are integrated. In order to evaluate these hypotheses, the investigators will assess perceived vertical using both vision-dependent and vision-independent paradigms.

Enrollment: 20 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• ages 18-65 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

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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20 participants in 1 patient group

intervention arm

Experimental group

Description:

In each participant the investigators will assess verticality perception in whole-body upright position by use of the SVV, the SPV and the SHV after static roll-tilt at ±90deg over 5min. Measurements will be obtained on a motor-driven turntable and two different roll-tilt positions will be applied (±90°). A visual line (SVV), a rod (SHV) or the turntable itself will be adjusted to indicate perceived direction of vertical. A total of three measuring sessions, each lasting about 60 minutes are scheduled.

Treatment:

Behavioral: presentation of visual and vestibular stimuli