title: Contributions of ocular vestibular evoked myogenic potentials and the electrooculogram to periocular potentials produced by whole-body vibration.
abstract: In this paper we report the results of an experiment to investigate the emergence of ocular vestibular evoked myogenic potentials (OVEMPs) during the linear vestibular ocular reflex (LVOR) evoked by whole-body vibration (WBV). OVEMP and electrooculogram (EOG) montages were employed to record periocular potentials (POPs) from six subjects during WBV in the nasooccipital (NO) axis over a range of frequencies from 0.5 to 64 Hz with approximately constant peak head acceleration of 1.0 ms(-2) (i.e., 0.1 g). Measurements were made in two context conditions: a fixation context to examine the effect of gaze eccentricity (0 vs. 20°), and a visual context, where a target was either head-fixed or earth-fixed. The principal results are that from 0.5 to 2 Hz POP magnitude in the earth-fixed condition is related to head displacement, so with constant acceleration at all frequencies it reduces with increasing frequency, but at frequencies greater than 2 Hz both POP magnitude and POP gain, defined as the ratio of POP magnitude at 20 and 0°, increase with increasing frequency. By exhibiting this high-pass characteristic, a property shared with the LVOR, the results are consistent with the hypothesis that the OVEMP, as commonly employed in the clinical setting, is a high-frequency manifestation of the LVOR. However, we also observed low-frequency acceleration following POPs in head-fixed conditions, consistent with a low-frequency OVEMP, and found evidence of a high-frequency visual context effect, which is also consistent with the OVEMP being a manifestation of the LVOR.
authors.affiliation: University of Manchester, School of Life Sciences, Oxford Road, Manchester, United Kingdom. neil.todd@manchester.ac.uk
authors.forename: Neil P M
authors.initials: NP
authors.lastname: Todd
authors.forename: Steven L
authors.initials: SL
authors.lastname: Bell
authors.forename: Aurore C
authors.initials: AC
authors.lastname: Paillard
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Griffin
mesh_terms: D000054:Acceleration; D000704:Analysis of Variance; D004576:Electromyography; D004585:Electrooculography; D005133:Eye Movements; D019416:Head Movements; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000294:innervation*; D012027:Reflex, Vestibulo-Ocular; D058585:Vestibular Evoked Myogenic Potentials; D014722:Vestibule, Labyrinth / Q000294:innervation*; D014732:Vibration; D014785:Vision, Ocular