Verticality Perception - Effects of Prolonged Roll-tilt in Healthy Human Subjects

The long-term goal of this research is to advance our knowledge of how the brain combines the information of multiple sensory systems coding for spatial orientation 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"). Here we evaluate different potential explanations for this bias using both vision-dependent and vision-independent paradigms of verticality perception.

Study Overview

• Status: Withdrawn
• Conditions: Perception; Vestibular
• Intervention / Treatment: Other: perception of vertical after static roll-tilt over 5min

• Study Type: Interventional
• Phase: Not Applicable

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:

1. ages 18-65 years
2. informed consent
3. absence of exclusion criteria

Exclusion Criteria:

1. peripheral-vestibular deficit
2. disturbed consciousness
3. history of sensory deficits
4. visual field deficits
5. other neurological or systemic disorder which can cause dementia or cognitive dysfunction
6. intake of antidepressants, sedatives, or neuroleptics
7. pregnancy, unless excluded by a negative pregnancy test
8. 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: Single intervention arm; This is the only arm in this study, measuring verticality perception after prolonged roll-tilt over 5min.	Other: perception of vertical after static roll-tilt over 5min; subjects will indicate perceived direction of vertical after 5min of static whole-body roll-tilt.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adjustment errors and trial-to-trial variability as assessed by line adjustments (subjective visual vertical (SVV)), adjustments of a rod (subjective haptic vertical (SHV)) or self-adjustments (subjective postural vertical (SPV)) after prolonged roll	In all three paradigms (SVV, SHV and SPV) the percept of direction of gravity will be assessed. Parameters will be adjustment errors ("accuracy") and trial-to-trial variability ("precision") based on repetitive adjustments of a luminous line (SVV) or a rod (SHV) after returning to upright position after a period of 5min in static roll-tilt at 90° left-ear down or right-ear down. During the roll-tilt period subjects remain either in the dark or observe a rotating optokinetic (random dot) pattern. Individual mean values and standard deviation (SD) will be calculated for all conditions. Adjustments with the joystick (SPV) will start from 90° ear-down positions after 5min of static roll.	measurements will be obtained over periods of 5min in a single session and day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Impact of a rotating optokinetic stimulus (velocity 60°/s) on adjustment errors as assessed by the SVV, the SHV or the SPV after 5min of static roll-tilt at +/- 90° roll.	During the 5min period with static roll at +/- 90deg ear-down positions subjects will be presented a rotating optokinetic stimulus (random dot pattern, clockwise or counter-clockwise rotation) in some conditions. Adjustment errors and trial-to-trial variability of conditions with the optokinetic stimulus will be compared to those without the optokinetic stimulus.	measurements will be obtained over periods of 5min in a single session and day

Collaborators and Investigators

• Sponsor: University of Zurich
• Investigators: Principal Investigator: Dominik Straumann, MD, University of Zurich, Switzerland

Study record dates

Study Major Dates

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

Study Registration Dates

• First Submitted: April 26, 2016
• First Submitted That Met QC Criteria: April 29, 2016
• First Posted (Estimate): May 3, 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: verticality perception
• Other Study ID Numbers: vert_perc_posttilt

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No