Visual-vestibular interaction during OVAR in the elderly.
This study assessed visual-otolith interaction in healthy older humans and compared responses from older subjects to those of younger subjects. Using off-vertical axis rotation (OVAR) to stimulate the otolith organs, eye movement responses, measured using electro-oculography, were recorded during rotation in the dark, rotation with an earth-fixed lighted visual surround, and rotation with a subject-fixed fixation target. Results indicated that older subjects, like young subjects, exhibit a modulation component that was as large during rotation with a lighted earth-fixed visual surround as that seen in the dark and a modulation component during rotation with a subject-fixed visual target that was incompletely suppressed. The modulation component was, in general, larger in the older subjects. This study confirms findings from a previous study of visual-otolith interaction in young subjects and suggests that older subjects, like young subjects, have difficulty visually suppressing the modulation component induced by off-vertical axis rotation.
Furman
J M
JM
Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15213, USA. furman@pitt.edu
Redfern
M S
MS
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D003624:Darkness; D005260:Female; D006801:Humans; D008297:Male; D017120:Nystagmus, Optokinetic / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation