VISUAL INFLUENCE ON HEAD SHAKING USING THE VESTIBULAR AUTOROTATION TEST

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Authors
  1. Cheung, B.
  2. Money, K.
  3. Sarkar, P.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
In this study we investigated the vestibular system by recording eye movements in response to voluntary high-frequency head-only movements using the Vestibular Autorotation Test (VAT; Western System Research Inc., Los Angeles, California). Our objective was to evaluate if the VAT could be implemented as one of the screening tests for vestibular integrity in aircrews and potential pilots. We attempted to record horizontal and vertical eye movements using electrooculography and head velocity with calibrated rotational velocity sensors. The gain and phase of the input and output signals were computed by discrete Fourier analysis. Seated subjects were instructed to fixate on a real or imaginary target while making smooth head oscillations about the spinal axis in time to an audible cue from 0.5 to 6.0 Hz during an 18-second test period. Test trials included two conditions in the light with subjects fixated on a real target (C1) or on an imaginary target on a blank screen (C2); three conditions in the dark in which subjects fixated on a imaginary target (C3), fixated on a remembered LED target in the dark after it was extinguished (C4), or fixated on a real target (C5). All the dark trials were performed after dark adaptation for 30 minutes. We were not able to obtain consistent vertical VOR response (when the subjects oscillated their head about the interaural axis) using the VAT. TRUNCATED
Keywords
Spatial disorientation;Spine
Report Number
DCIEM-95-RP-27 — Reprint
Date of publication
30 Apr 1996
Number of Pages
12
Reprinted from
Journal of Vestibular Research, vol 6, no 6, 1996, p 411-422
DSTKIM No
97-01397
CANDIS No
501516
Format(s):
Hardcopy;Document Image stored on Optical Disk

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