September 2011
Volume 11, Issue 11
Free
Vision Sciences Society Annual Meeting Abstract  |   September 2011
Reponses of human V6 to random motion, egomotion_incompatible and egomotion-compatible optic flow
Author Affiliations
  • Velia Cardin
    Psychology Department. Royal Holloway, University of London. Egham, Surrey, TW20 0EX, London
  • Rachael Sherrington
    Psychology Department. Royal Holloway, University of London. Egham, Surrey, TW20 0EX, London
  • Lara Hemsworth
    Psychology Department. Royal Holloway, University of London. Egham, Surrey, TW20 0EX, London
  • Andrew T Smith
    Psychology Department. Royal Holloway, University of London. Egham, Surrey, TW20 0EX, London
Journal of Vision September 2011, Vol.11, 711. doi:10.1167/11.11.711
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Velia Cardin, Rachael Sherrington, Lara Hemsworth, Andrew T Smith; Reponses of human V6 to random motion, egomotion_incompatible and egomotion-compatible optic flow. Journal of Vision 2011;11(11):711. doi: 10.1167/11.11.711.

      Download citation file:


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

      ×
  • Supplements
Abstract

The extraction of optic flow cues from the visual scene is fundamental for guidance of egomotion. Area V6 is thought to be important in this role because of the properties of macaque V6 (Galletti et al., 1999), and because human V6 (hV6) responds differentially to egomotion-compatible optic flow compared to: (a) egomotion-incompatible flow (Cardin & Smith, 2010), and (b) incoherent motion (Pitzalis et al., 2010). It is not clear, however, whether hV6 responds more strongly to egomotion-incompatible global motion than to incoherent motion. This is relevant not only for determining the functional properties of hV6, but also in order to choose optimal stimuli for localising hV6 accurately with fMRI. Localization with retinotopic mapping is difficult and there is a need for a simple, reliable method. We conducted an event-related 3T fMRI experiment in which participants viewed a display of dots that moved randomly (RM), followed a time-varying optic flow trajectory in a single, egomotion-compatible (EC) display, or formed an egomotion-incompatible (EI) 3 × 3 array of optic flow patches as used in our previous work. Analysis was conducted by fitting a GLM. Beta values were extracted from retinotopically defined regions and averaged across hemispheres. Results from hV6 show an ordering of response magnitudes: EC > EI > RM. Neighbouring areas V3A and V7 responded more strongly to EC than to RM, but about equally to EC and EI. Our results suggest that hV6 may have a general role in the extraction of global motion but, in clear contrast to other neighbouring motion areas, is especially concerned with encoding EC stimuli. They suggest two strategies for localising hV6: (1) contrasting EC and EI; or (2) contrasting EC and RM, which will give a larger differential response, but requires use of standard retinotopic mapping in order to exclude voxels from neighbouring regions that also show a EC > RM preference.

Wellcome Trust. 
×
×

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.

×