title: Vestibulo-ocular reflex suppression during head-fixed saccades reveals gaze feedback control.
abstract: Previous experiments have shown that the vestibulo-ocular reflex (VOR) is partially suppressed during large head-free gaze (gaze = eye-in-head + head-in-space) shifts when both the eyes and head are moving actively, on a fixed body, or when the eyes are moving actively and the head passively on a fixed body. We tested, in human subjects, the hypothesis that the VOR is also suppressed during gaze saccades made with en bloc, head and body together, rotations. Subjects made saccades by following a target light. During some trials, the chair rotated so as to move the entire body passively before, during, or after a saccade. The modulation of the VOR was a function of both saccade amplitude and the time of the head perturbation relative to saccade onset. Despite the perturbation, gaze remained accurate. Thus, VOR modulation is similar when gaze changes are programmed for the eyes alone or for the eyes and head moving together. We propose that the brain always programs a change in gaze using feedback based on gaze and head signals, rather than on separate eye and head trajectories.
authors.affiliation: Pierre et Marie Curie Paris-6 Université, INSERM UMRS 975, CNRS 7225, Paris, France, Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-4435 pierre.daye@gmail.com.
authors.forename: Pierre M
authors.identifier: http://orcid.org/0000-0002-0586-396X
authors.initials: PM
authors.lastname: Daye
authors.affiliation: Departments of Neurology.
authors.forename: Dale C
authors.identifier: http://orcid.org/0000-0003-4328-0199
authors.initials: DC
authors.lastname: Roberts
authors.affiliation: Departments of Neurology, Otolaryngology, Ophthalmology, and Neuroscience, The Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287, and.
authors.forename: David S
authors.identifier: http://orcid.org/0000-0003-3909-2494
authors.initials: DS
authors.lastname: Zee
authors.affiliation: Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-4435.
authors.forename: Lance M
authors.identifier: http://orcid.org/0000-0003-3640-0762
authors.initials: LM
authors.lastname: Optican
mesh_terms: D000328:Adult; D000368:Aged; D025461:Feedback, Physiological / Q000502:physiology*; D006257:Head; D006801:Humans; D008297:Male; D008875:Middle Aged; D009949:Orientation / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D012438:Saccades / Q000502:physiology*
keywords: VOR; eye–head saccades; feedback control