Extrastriate visual cortical recruitment during tactile form perception in the sighted
Multiple Paper Presentation

K. Sathian
Dept. of Neurology, Emory University School of Medicine, Atl

     Abstract ID Number: 22

Abstract
There are now a number of studies from different groups indicating that normally sighted subjects recruit areas of extrastriate visual cortex during various tactile tasks. This talk will review evidence that such visual cortical engagement is quite task-specific, so that extrastriate areas involved in particular visual tasks are recruited in the corresponding tactile versions. Mental rotation of tactile (and visual) forms selectively activates superior parietal cortex in the dorsal visual pathway. Discrimination and identification of tactile (and visual) forms selectively activates the lateral occipital complex (LOC) in the ventral visual pathway. LOC activation is greater during discrimination of global tactile form, a macrospatial task, than during detection of a gap in a bar, a microspatial tactile task. The macrospatial task is more associated with visual imagery than the microspatial task, suggesting that visual imagery may be at least partly responsible for visual cortical activation.

To be Presented at the Following Symposium:
Consequences of sensory loss
Other papers in this Symposium:

• Brigitte Roeder
  Experimental and Biological Psychology, Philipps-University
  The consequences of having no vision
• Karen Dobkins
  Psychology Department, UC San Diego
  Visual plasticity in the deaf: evidence from psychophysics and fMRI
• Lotfi B. Merabet
  Department of Neurology, Harvard Medical School
  Jessica Andrews
  Department of Neurology, Harvard Medical School
  Hugo Theoret
  Department of Neurology, Harvard Medical School
  Alvaro Pascual-Leone
  Department of Neurology, Harvard Medical School
  Investigating the role of occipital cortex in tactile processing: In search of a meta-modal brain