Adaptation Reaction
Conditions
Brief summary
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.
Interventions
BEHAVIORALpresentation of visual and vestibular stimuli
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.
Sponsors
University of Zurich
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* ages 18-65 years * informed consent * absence of
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| adjustment errors of the subjective visual/haptic/postural vertical in upright position after prolonged whole-body roll-tilt positions. | 10 minutes (i.e. short-term adaptation) | the accuracy and precision of visual vertical adjustments after prolonged roll tilt are quantified. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| changes in adjustment errors of the subjective visual vertical when providing an additional optokinetic stimulus | 10 minutes (i.e. short-term adaptation) | This is the same as in outcome 1, but an additional visual (optokinetic) stimulus is added |
| changes in adjustment errors of the subjective haptic vertical when providing an additional optokinetic stimulus | 10 minutes (i.e. short-term adaptation) | This is the same as in outcome 1, but an additional visual (optokinetic) stimulus is added |
| changes in adjustment errors of the subjective postural vertical when providing an additional optokinetic stimulus | 10 minutes (i.e. short-term adaptation) | This is the same as in outcome 1, but an additional visual (optokinetic) stimulus is added |
Countries
Switzerland
Contacts
Primary ContactDominik Straumann, MD
Backup ContactAlexander A Tarnutzer, MD
Outcome results
None listed