|
Visual attention and visual remapping in patients with damage to posterior parietal cortex| old_uid | 11104 |
|---|
| title | Visual attention and visual remapping in patients with damage to posterior parietal cortex |
|---|
| start_date | 2012/03/19 |
|---|
| schedule | 11h-12h30 |
|---|
| online | no |
|---|
| location_info | 2e étage |
|---|
| details | Invité par l'équipe Vision |
|---|
| summary | I will review evidence showing that the posterior parietal cortex (PPC) is acrucial cortical region for visual attention and visual remapping in humans, as suggested by the *Balint-Holmes **syndrome* and also by monkey electrophysiology. We also review evidence showing a right hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both *neglect *and *constructional apraxia*. More specifically, we review findings from the intervening saccade paradigm in humans and present data suggesting a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: Following damage to the right dorsal PPC as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment /when/ /the second saccade had to be directed rightward/.This singular and lateralized deficit cannot result solely from the patient's cortical lesion and therefore, we propose that it is due to his callosal lesion which may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades toward a remapped target location. This suggests a specialized right hemispheric network for visuo-spatial remapping which subsequently transfers target location information to downstream saccade planning regions which are symmetrically organized. |
|---|
| responsibles | Rämä |
|---|
| |
|