The integration of vestibular signals in parietal cortex contributing to observer-independent representations of the world
Multiple Paper Presentation

Peter Thier
Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen

Uwe Ilg
Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen

Peter W. Dicke
Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen

     Abstract ID Number: 220
     Last modified: May 22, 2006
     Presentation date: 06/19/2006 5:30 PM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
Parietooccipital cortex contains severals areas with distinct roles in the generation of smooth-pursuit eye movements. Area MT contributes to smooth-pursuit by extracting retinal slip of the target image, one of the key inputs driving smooth-pursuit. On the other hand, the lateral part of neighboring area MST (=MSTl) seems to contain the explicit representation of object motion in world-centered coordinates. This is suggested by the existence of MSTl visual tracking (VT-) neurons which are multimodal neurons sensitive to retinal image slip, to eye movements as well as to head movements with identical preferred directions. The notion that these three inputs are used to reconstruct the movement of an object in world-coordinates is supported by the observation that their discharge persists, when movement of the object is compensated by eye and/or head movements, stabilizing the object image on the retina. This word-centered representation of object motion may be advantageous for a number of functions beyond the programming of pursuit. However, its role in smooth-pursuit is clearly demonstrated by the fact that lesions of MSTl cause an ipsiversive smooth-pursuit deficit that can be replicated by “lesioning” a VT-neuron-like layer in a model generating smooth combined eye and head pursuit movements.

To be Presented at the Following Symposium:
Vestibular contribution to multisensory perception and movement control.
Other papers in this Symposium:

• Alain Berthoz
  College de France, Paris
  The role of the vestibular system in multisensory integration during navigation
• Stuart Smith
  School of Psychology, University College Dublin
  Multisensory self-motion estimation, old ideas and new data
• Fabrizio Doricchi
  Universita’ degli Studi “La Sapienza” and Fondazione Santa Lucia, Rome Italy
  Crossmodal integration of vestibular cues, attentional orienting and space representation