In recent experiments involving acceleration stimuli, researchers instructed subjects to focus on a visual target while measuring the vestibulo-ocular reflex (VOR) in one eye. These experiments showed conclusively that the VOR is influenced by target distance. We, on the other hand, were interested in investigating the VOR of subjects accelerated in complete darkness. Specifically, we wished to determine the subject's vergence point, which cannot be accomplished using data obtained from only one eye. Hence, a binocular eye-tracking system that works in the dark was required. In the experiment described in this thesis, the subject was rotated in the dark on NAMRL's Coriolis Acceleration Platform. The position of each pupil center was tracked and recorded by two helmet-mounted infrared cameras connected to a computer-controlled data acquisition system. The position data were used to calculate the angles through which the eyes rotated, and then trigonometric principles were applied to construct the line of sight for each eye for any moment in time; the intersection of these two lines is the vergence point. With the NAMRL binocular eye-tracking system, an accelerating subject's vergence point can accurately be determined if it is less than 1. 5 meters away. The vergence data obtained from this experiment suggest that vergence distance does not exclusively drive the VOR in the dark. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/46273 |
| Date | 17 December 2008 |
| Creators | Fajardo, Ann B. |
| Contributors | Engineering Mechanics, Grant, John Wallace, Kraige, Luther Glenn, Love, Brian J. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | xi, 98 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 35718058, LD5655.V855_1996.F353.pdf |
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