June 2007
Volume 7, Issue 9
Free
Vision Sciences Society Annual Meeting Abstract  |   June 2007
Disambiguation of optic flow with vestibular signals
Author Affiliations
  • Paul MacNeilage
    Vision Science Program, UC Berkeley
  • John Butler
    Max Planck Institute for Biological Cybernetics
  • Heinrich Buelthoff
    Max Planck Institute for Biological Cybernetics
  • Martin Banks
    Vision Science Program, UC Berkeley
Journal of Vision June 2007, Vol.7, 101. doi:10.1167/7.9.101
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Paul MacNeilage, John Butler, Heinrich Buelthoff, Martin Banks; Disambiguation of optic flow with vestibular signals. Journal of Vision 2007;7(9):101. doi: 10.1167/7.9.101.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Optic flow is generated by observer motion relative to stationary objects, by movement of objects relative to a stationary observer, and by combinations of those situations. To determine the relative contributions of object and self motion to the observed optic flow, the nervous system can use vestibular signals. An object's speed relative to earth is given by the difference between its speed relative to the head and the head's speed relative to the earth. The variance of the difference is the sum of the component variances: σ2obj2vis2vest. In contrast, if observers estimate self-motion from optic flow and vestibular signals, and assume a stationary visual scene, visual and vestibular estimates may be combined in a weighted average to yield more precise self-motion estimates: σ2self=(σ2visσ2vest)/(σ2vis2vest). So depending on whether the subject reports object motion or self-motion, the two-modality variance is predicted to be respectively higher or lower than the component variances. To test these predictions, we measured speed-discrimination thresholds for fore-aft translations and roll rotations. There were two single-modality conditions, Visual and Vestibular, and two multi-modality conditions, Self-motion and Object-motion. In the Visual, Vestibular, and Self-motion conditions, observers indicated if the movement was faster or slower than a standard. In the Object-motion condition, observers indicated if the object appeared to move with or against the self-motion. Experiments were conducted on a rotating chair and translating motion platform. The stereoscopic projection system was mounted on the apparatus. Stimuli were random-dot planes that rotated clockwise or anti-clockwise or translated forwards or backwards. In the translation conditions, multi-modal object-motion thresholds were, as predicted, higher than single-modality thresholds, and multi-modal self-motion thresholds were, as predicted, generally lower than single-modality thresholds. Results from the rotation conditions were less clear. Possible causes of differing results for translations and rotations will be discussed.

MacNeilage, P. Butler, J. Buelthoff, H. Banks, M. (2007). Disambiguation of optic flow with vestibular signals [Abstract]. Journal of Vision, 7(9):101, 101a, http://journalofvision.org/7/9/101/, doi:10.1167/7.9.101. [CrossRef]
Footnotes
 NIH EY014194
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×