Skip Navigation


Cerebral Cortex Advance Access first published online on March 2, 2005
This version published online on March 14, 2005
Cerebral Cortex, doi:10.1093/cercor/bhi033
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
15/10/1547    most recent
bhi033v2
bhi033v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Khan, A. Z.
Right arrow Articles by Crawford, J. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Khan, A. Z.
Right arrow Articles by Crawford, J. D.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2005. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oupjournals.org

Article

Impairment of Gaze-centered Updating of Reach Targets in Bilateral Parietal-Occipital Damaged Patients

Aarlenne Z. Khan 1, Laure Pisella 2, Yves Rossetti 3, Alain Vighetto 4, and J. Douglas Crawford 5*

1 Centre for Vision Research, CIHR Group for Action and Perception and Department of Psychology, York University, Toronto, Ontario, Canada, M3J 1P3; Espace et Action, INSERM U534 and Université Claude Bernard, 16 avenue Doyen Lépine, 69676 Bron, France
2 Espace et Action, INSERM U534 and Université Claude Bernard, 16 avenue Doyen Lépine, 69676 Bron, France; Institut Fédératif des Neurosciences de Lyon, Bâtiment B13, 59 boulevard Pinel, 69394 Lyon, France
3 Espace et Action, INSERM U534 and Université Claude Bernard, 16 avenue Doyen Lépine, 69676 Bron, France; Institut Fédératif des Neurosciences de Lyon, Bâtiment B13, 59 boulevard Pinel, 69394 Lyon, France; Hospices Civils de Lyon, 59 boulevard Pinel, 69391 Lyon, France and Université Claude Bernard, Lyon, France
4 Institut Fédératif des Neurosciences de Lyon, Bâtiment B13, 59 boulevard Pinel, 69394 Lyon, France; Hospices Civils de Lyon, 59 boulevard Pinel, 69391 Lyon, France and Université Claude Bernard, Lyon, France
5 Centre for Vision Research, CIHR Group for Action and Perception and Department of Psychology, York University, Toronto, Ontario, Canada, M3J 1P3; Departments of Biology and Kinesiology and Health Science, York University, Toronto, Ontario, Canada, M3J 1P3

* To whom correspondence should be addressed.
J. Douglas Crawford, E-mail: jdc{at}yorku.ca


  Abstract

Recent studies have suggested that internal updating of visuospatial targets in humans occurs in gaze-centered coordinates and takes place in the parietal and extrastriate cortices. We explored how information for reaching is updated in two patients with bilateral lesions in these areas. Subjects performed two visuomotor tasks: (i) a fixation reaching task, which began with the appearance of one of five fixation positions (varying eye positions) followed by a central reaching target. Subjects reached to the target while fixating on the presented fixation position (relative to gaze the target was always presented in the periphery); and (ii) a saccade reaching task, in which subjects foveated on the central reaching target, then made a saccade to the presented fixation position before reaching to the central target. In both tasks, subjects reached to targets after a 500 or 5000 ms delay. Gaze-centered updating predicts similarities in reaching errors between fixation and saccade trials. Control subjects showed evidence for gaze-centered updating during both 500 and 5000 ms delay conditions. In contrast, patient AT, who had extensive occipital-parietal damage, only showed signs of gaze-centered representation after 5 s. Patient IG, with a more focal lesion in the parietal cortices, showed partial updating in gaze-centered coordinates when reaching with the small memory delay but recovered a complete gaze-centered representation after the longer delay. This suggests that patients with bilateral occipital-parietal lesions may rely on non-gaze-centered frames to store immediate target locations in reaching space but, given enough time, this information may be rerouted to access other gaze-centered motor cortical mechanisms.

Keywords: eye-centered coordinates; eye-hand coordination; optic ataxia; posterior parietal cortex; reference frames; visual updating.
The affiliation for J. Douglas Crawford has been corrected.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Neurophysiol.Home page
G. U. Sorrento and D. Y. P. Henriques
Reference Frame Conversions for Repeated Arm Movements
J Neurophysiol, June 1, 2008; 99(6): 2968 - 2984.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
S. Van Pelt and W. P. Medendorp
Updating Target Distance Across Eye Movements in Depth
J Neurophysiol, May 1, 2008; 99(5): 2281 - 2290.
[Abstract] [Full Text] [PDF]

Home page
 Cereb CortexHome page
J. Fernandez-Ruiz, H. C. Goltz, J. F. X. DeSouza, T. Vilis, and J. D. Crawford
Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, in a Visual Motor Dissociation Task
Cereb Cortex, October 1, 2007; 17(10): 2283 - 2292.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. Vesia, J. A. Monteon, L. E. Sergio, and J. D. Crawford
Hemispheric Asymmetry in Memory-Guided Pointing During Single-Pulse Transcranial Magnetic Stimulation of Human Parietal Cortex
J Neurophysiol, December 1, 2006; 96(6): 3016 - 3027.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
L. Ren, A. Z. Khan, G. Blohm, D.Y.P. Henriques, L. E. Sergio, and J. D. Crawford
Proprioceptive Guidance of Saccades in Eye-Hand Coordination
J Neurophysiol, September 1, 2006; 96(3): 1464 - 1477.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.