Verticality Perception Assessed by the Haptic Vertical

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Other: changes in whole-body roll position and visual/haptic stimuli presented

• Registration Number: NCT02980432
• Lead Sponsor: University of Zurich

Brief 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.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-10
• Study First Submitted: 2016-11-16
• Study First Submitted QC: 2016-11-29
• Study First Posted: 2016-12-02
• Status Verified: 2018-06
• Primary Completion: 2018-06-01
• Study Completion: 2018-06-28
• Last Update Submitted: 2018-06-28
• Last Update Posted: 2018-07-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 19

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
intervention arm	changes in whole-body roll position and visual/haptic stimuli presented	all participants will be assigned to the same arm. Interventions applied include presenting a visual line or a rod with or without a moving (rotating) background while being in different whole-body roll positions. Participants will be asked to adjust the line or the rod along perceived direction of gravity.

Primary Outcome Measures

Name	Time	Method
Trial-to-trial variability of aligning a rod along perceived direction of gravity while an optokinetic stimulus is presented.	60 minutes	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).
Adjustment errors of aligning a rod along perceived direction of gravity while an optokinetic stimulus is presented.	60 minutes	This outcome parameter focuses on the adjustment errors of the subjective haptic vertical while presenting a visual bias (i.e. an optokinetic rotatory stimulus).

Secondary Outcome Measures

Name	Time	Method
Comparison of adjustment errors between the subjective haptic vertical and the subjective visual vertical	60 minutes
Comparison of adjustment errors of perceived vertical using the subjective haptic vertical with and without presenting an optokinetic stimulus	60 minutes

Trial Locations

Locations (1)

University Hospital Zurich, Dept. of Neurology; 🇨🇭 Zurich, ZH, Switzerland