Verticality Perception Assessed by the Haptic Vertical

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

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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: changes in whole-body roll position and visual/haptic stimuli presented

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • ZH
    • Zurich, ZH, Switzerland, 8091
      • University Hospital Zurich, Dept. of Neurology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: intervention arm; 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.	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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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
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 Outcome Measures

Outcome Measure	Time Frame
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

Collaborators and Investigators

• Sponsor: University of Zurich

Study record dates

Study Major Dates

• Study Start: October 1, 2016
• Primary Completion (Actual): June 1, 2018
• Study Completion (Actual): June 28, 2018

Study Registration Dates

• First Submitted: November 16, 2016
• First Submitted That Met QC Criteria: November 29, 2016
• First Posted (Estimate): December 2, 2016

Study Record Updates

• Last Update Posted (Actual): July 2, 2018
• Last Update Submitted That Met QC Criteria: June 28, 2018
• Last Verified: June 1, 2018

More Information

Terms related to this study

• Keywords: vestibular; vision; spatial orientation; optokinetic
• Other Study ID Numbers: shv_okn_study

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO