Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Graduation


Document Type


Degree Name

Doctor of Audiology (AuD)


Department of Communication Sciences and Disorders


Erin Piker

Carol Dudding

Lincoln Gray


Both the vestibular system and optokinetic system generate conjugate eye movements in response to either movement of the head or movement of the visual surround. Both systems help to maintain gaze stability. While the VOR is most sensitive to input frequencies above .2 Hz, the optokinetic system helps maintain gaze stability at lower frequencies. Previous research on perceptual thresholds across the two sensory modalities shows that there are frequency-dependent differences between vestibular and visual perception. The purpose of this study is to extend previous vestibular psychophysics work by 1) comparing magnitude estimates from vestibular stimulation to visual stimulation across multiple frequencies, and 2) assess the feasibility of using virtual reality to provide an optokinetic stimulus equal to that of the rotary chair at frequencies where both systems are sensitive.

Participants were exposed to 12 experimental conditions of angular rotation of varying frequencies and peak velocities across both sensory modalities. Vestibular stimulation was provided with a rotary chair and equivalent visual stimulation was provided with a virtual reality headset. Participants provided magnitude estimates of their speed and spatial orientation using a visual analog scale. Results reveal that speed magnitude estimates increased with peak velocity and frequency for both modalities. Spatial orientation magnitude estimates decreased with increasing frequency and increased with increasing peak velocity. Spatial orientation was underestimated under visual stimulation. Based on these results, it was concluded that at frequencies from 0.08 to 0.32 Hz, both vestibular and visual modalities provide adequate cues for motion sensitivity and virtual reality can be used as an OKN stimulus to assess motion perception (specifically speed/intensity).



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.