A Versatile Stereoscopic Visual Display System for Vestibular and Oculomotor Research

Article type: Research Article

Authors: Kramer, Phillip D.^{a; b;} | Roberts, Dale C.^a | Shelhamer, Mark^{b; c} | Zee, David S.^{a; b; d; e}

Affiliations: [a] Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA | [b] Departments of Otolaryngology-Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA | [c] Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA | [d] Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA | [e] Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

Note: [1] Reprint address: Phillip D. Kramer, Pathology Bldg. 2-210, 600 N. Wolfe St., Baltimore, MD 21287-6921. Tel: (410) 614-1575; Fax: (410) 614-1746; E-mail: [email protected]

Abstract: Testing of the vestibular system requires a vestibular stimulus (motion) and/or a visual stimulus. We have developed a versatile, low cost, stereoscopic visual display system, using “virtual reality” (VR) technology. The display system can produce images for each eye that correspond to targets at any virtual distance relative to the subject, and so require the appropriate ocular vergence. We elicited smooth pursuit, “stare” optokinetic nystagmus (OKN) and after-nystagmus (OKAN), vergence for targets at various distances, and short-term adaptation of the vestibulo-ocular reflex (VOR), using both conventional methods and the stereoscopic display. Pursuit, OKN, and OKAN were comparable with both methods. When used with a vestibular stimulus, VR induced appropriate adaptive changes of the phase and gain of the angular VOR. In addition, using the VR display system and a human linear acceleration sled, we adapted the phase of the linear VOR. The VR-based stimulus system not only offers an alternative to more cumbersome means of stimulating the visual system in vestibular experiments, it also can produce visual stimuli that would otherwise be impractical or impossible. Our techniques provide images without the latencies encountered in most VR systems. Its inherent versatility allows it to be useful in several different types of experiments, and because it is software driven it can be quickly adapted to provide a new stimulus. These two factors allow VR to provide considerable savings in time and money, as well as flexibility in developing experimental paradigms.

Keywords: virtual reality, head mounted display, vestibular, oculomotor

DOI: 10.3233/VES-1998-8503

Journal: Journal of Vestibular Research, vol. 8, no. 5, pp. 363-379, 1998