Affiliations: [a] Department of Neurology, Friedrich-Schiller-University, Jena, Germany | [b] Departments of Otolaryngology-Head & Neck Surgery, and Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA | [c] New Jersey Neuroscience Institute, Seton Hall University, JFK Medical Center, Edison, NJ 08818, USA | [d] Departments of Neurology, Ophthalmology, and Otolaryngology-Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
Abstract: The phase of the translational linear VOR (LVOR) can be adaptively modified by exposure to a visual-vestibular mismatch. We extend here our earlier work on LVOR phase adaptation, and discuss the role of the oculomotor neural integrator. Ten subjects were oscillated laterally at 0.5 Hz, 0.3 g peak acceleration, while sitting upright on a linear sled. LVOR was assessed before and after adaptation with subjects tracking the remembered location of a target at 1 m in the dark. Phase and gain were measured by fitting sine waves to the desaccaded eye movements, and comparing sled and eye position. To adapt LVOR phase, the subject viewed a computer-generated stereoscopic visual display, at a virtual distance of 1 m, that moved so as to require either a phase lead or a phase lag of 53 deg. Adaptation lasted 20 min, during which subjects were oscillated at 0.5 Hz/0.3 g. Four of five subjects produced an adaptive change in the lag condition (range 4–45 deg), and each of five produced a change in the lead condition (range 19–56 deg), as requested. Changes in drift on eccentric gaze suggest that the oculomotor velocity-to-position integrator may be involved in the phase changes.
