Experimental Brain Research

, Volume 186, Issue 4, pp 677–681

Vestibular thresholds for yaw rotation about an earth-vertical axis as a function of frequency

  • Luzia Grabherr
  • Keyvan Nicoucar
  • Fred W. Mast
  • Daniel M. Merfeld
Research Note

DOI: 10.1007/s00221-008-1350-8

Cite this article as:
Grabherr, L., Nicoucar, K., Mast, F.W. et al. Exp Brain Res (2008) 186: 677. doi:10.1007/s00221-008-1350-8

Abstract

Perceptual direction detection thresholds for yaw rotation about an earth-vertical axis were measured at seven frequencies (0.05, 0.1, 0.2, 0.5, 1, 2, and 5 Hz) in seven subjects in the dark. Motion stimuli consisted of single cycles of sinusoidal acceleration and were generated by a motion platform. An adaptive two-alternative categorical forced-choice procedure was used. The subjects had to indicate by button presses whether they perceived yaw rotation to the left or to the right. Thresholds were measured using a 3-down, 1-up staircase paradigm. Mean yaw rotation velocity thresholds were 2.8 deg s−1 for 0.05 Hz, 2.5 deg s−1 for 0.1 Hz, 1.7 deg s−1 for 0.2 Hz, 0.7 deg s−1 for 0.5 Hz, 0.6 deg s−1 for 1 Hz, 0.4 deg s−1 for 2 Hz, and 0.6 deg s−1 for 5 Hz. The results show that motion thresholds increase at 0.2 Hz and below and plateau at 0.5 Hz and above. Increasing velocity thresholds at lower frequencies qualitatively mimic the high-pass characteristics of the semicircular canals, since the increase at 0.2 Hz and below would be consistent with decreased gain/sensitivity observed in the VOR at lower frequencies. In fact, the measured dynamics are consistent with a high pass filter having a threshold plateau of 0.71 deg s-1 and a cut-off frequency of 0.23 Hz, which corresponds to a time constant of approximately 0.70 s. These findings provide no evidence for an influence of velocity storage on perceptual yaw rotation thresholds.

Keywords

Vestibular Psychophysics Semicircular canals Sensory threshold Human 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Luzia Grabherr
    • 1
  • Keyvan Nicoucar
    • 2
    • 3
  • Fred W. Mast
    • 1
  • Daniel M. Merfeld
    • 2
    • 3
  1. 1.Department of PsychologyUniversity of LausanneLausanneSwitzerland
  2. 2.Jenks Vestibular Physiology LaboratoryMassachusetts Eye and Ear InfirmaryBostonUSA
  3. 3.Otology and LaryngologyHarvard Medical SchoolBostonUSA

Personalised recommendations