title: The human translational vestibulo-ocular reflex in response to complex motion.
abstract: We studied the translational vestibulo-ocular reflex (tVOR) in four healthy human subjects during complex, unpredictable sum-of-sines head motion (combination of 0.73, 1.33, 1.93, and 2.93 Hz), while subjects viewed a target 15 cm away. Ideal eye velocity was calculated from recorded head motion; actual eye velocity was measured with scleral coils. The gain and phase for each frequency component was determined by least-squares optimization. Gain averaged approximately 40% and did not change with frequency; phase lag increased with frequency to a maximum of 66°. Fitting actual to ideal eye velocity predicted a tVOR latency of 48 m/s for vertical and 38 m/s for horizontal translation. These findings provide further evidence that the normal tVOR is considerably undercompensatory, even at low frequencies if the stimulus is not predictable. The similarity of this behavior to that of pursuit suggests that these two eye movements may share some aspects of neural processing.
authors.affiliation: Department of Neurology, Case Western Reserve University, Cleveland, Ohio, USA. mark.walker@case.edu
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
authors.forename: Ke
authors.initials: K
authors.lastname: Liao
mesh_terms: D000328:Adult; D000465:Algorithms; D005133:Eye Movements / Q000502:physiology; D019416:Head Movements / Q000502:physiology; D006801:Humans; D016018:Least-Squares Analysis; D008959:Models, Neurological; D009038:Motion; D009039:Motion Perception / Q000502:physiology; D010037:Otolithic Membrane / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012438:Saccades / Q000502:physiology