Vestibular and oculomotor influences on visual dependency.
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Published version
Accepted version
Author(s)
Roberts, RE
Da Silva Melo, M
Siddiqui, AA
Arshad, Q
Patel, M
Type
Journal Article
Abstract
The degree to which a person relies on visual stimuli for spatial orientation is termed visual dependency (VD). VD is considered a perceptual trait or cognitive style influenced by psychological factors and mediated by central re-weighting of the sensory inputs involved in spatial orientation. VD is often measured using the rod-and-disk test, wherein participants align a central rod to the subjective visual vertical (SVV) in the presence of a background that is either stationary or rotating around the line of sight - dynamic SVV. Although this task has been employed to assess VD in health and vestibular disease, it is unknown what effect torsional nystagmic eye movements may have on individual performance. Using caloric ear irrigation, 3D video-oculography and the rod-and-disk test, we show that caloric torsional nystagmus modulates measures of visual dependency and demonstrate that increases in tilt after irrigation are positively correlated with changes in ocular torsional eye movements. When the direction of the slow phase of the torsional eye movement induced by the caloric is congruent with that induced by the rotating visual stimulus, there is a significant increase in tilt. When these two torsional components are in opposition there is a decrease. These findings show that measures of visual dependence can be influenced by oculomotor responses induced by caloric stimulation. The findings are of significance for clinical studies as they indicate that VD, which often increases in vestibular disorders, is not only modulated by changes in cognitive style but also by eye movements, in particular nystagmus.
Date Issued
2016-09-20
Date Acceptance
2016-06-27
Citation
Journal of Neurophysiology, 2016, 116 (3), pp.1480-1487
ISSN
1522-1598
Publisher
American Physiological Society
Start Page
1480
End Page
1487
Journal / Book Title
Journal of Neurophysiology
Volume
116
Issue
3
Copyright Statement
Copyright © 2016 the American Physiological Society
Licensed under Creative Commons Attribution CC-BY 3.0: the American Physiological Society.
Licensed under Creative Commons Attribution CC-BY 3.0: the American Physiological Society.
Identifier
http://www.ncbi.nlm.nih.gov/pubmed/27358321
PII: jn.00895.2015
Subjects
Visual dependency
field dependence-independence
ocular torsion
subjective visual vertical
vestibular
Publication Status
Published