Verticality Perception Assessed by the Haptic Vertical

Healthy Clinical Trial

Official title:

Verticality Perception - Modulatory Effect of a Rotating Optokinetic Stimulus on the Haptic Vertical in Healthy Human Subjects

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02980432
• Other study ID #: shv_okn_study
• Status: Completed
• Phase: N/A
• Start date: October 2016
• Est. completion date: June 28, 2018

Study information

• Verified date: June 2018
• Source: University of Zurich
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The investigators previously shown that a rotating optokinetic stimulus results in shifts of the subjective visual vertical in healthy human subjects. However, the origin of these shifts is still poorly understood. Both torsional displacement of the eyes and a shift in the internal estimate of direction of gravity have been proposed as potential explanations. Here the investigators use a vision-independent setup to differentiate between these two hypotheses, predicting no impact of a rotating stimulus on the subjective haptic vertical if torsion triggers the shift.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 19
• Est. completion date: June 28, 2018
• Est. primary completion date: June 1, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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

Related Conditions & MeSH terms

• Healthy

Intervention

Other:
• changes in whole-body roll position and visual/haptic stimuli presented
In different whole-body roll positions subjects will be presented a luminous line or a rod in combination with a moving or stationary background. Participants will be asked to align the line or the rod along perceived direction of gravity.

Locations

Country	Name	City	State
Switzerland	University Hospital Zurich, Dept. of Neurology	Zurich	ZH

Sponsors (1)

Lead Sponsor	Collaborator
University of Zurich

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Adjustment errors of aligning a rod along perceived direction of gravity while an optokinetic stimulus is presented.	This outcome parameter focuses on the adjustment errors of the subjective haptic vertical while presenting a visual bias (i.e. an optokinetic rotatory stimulus).	60 minutes
Primary	Trial-to-trial variability of aligning a rod along perceived direction of gravity while an optokinetic stimulus is presented.	This outcome parameter focuses on the trial-to-trial variability of rod alignments along perceived direction of gravity when presenting a visual bias cue (i.e. an optokinetic rotatory stimulus).	60 minutes
Secondary	Comparison of adjustment errors between the subjective haptic vertical and the subjective visual vertical		60 minutes
Secondary	Comparison of adjustment errors of perceived vertical using the subjective haptic vertical with and without presenting an optokinetic stimulus		60 minutes