 |
| Research article summary (published 30 Dec 2002): |
Interhemispheric visual interaction in a patient with posterior callosectomy.
Full Abstract
The role of anterior commissure (AC) and anterior parts of corpus callosum in visual interactions was investigated in a partial split-brain patient whose posterior and middle parts of the corpus callosum were resected surgically leaving intact only a thin portion of anterior corpus callosum. Although the primary visual areas of the two hemispheres are disconnected in the patient, we found that visual distracters presented to one hemisphere (in a crowding paradigm) impaired recognition of the target stimulus presented to the other hemisphere. The normal control group showed the same result. To rule out the possible contribution of subcortical areas to this interaction, we repeated the same crowding task with texture-defined stimuli. The patient again showed an interhemispheric interaction, even though subcortical structures respond poorly or do not respond at all to texture defined shapes. Despite the evidence for interhemispheric interaction, a classic match-to-sample task confirmed that the patient was unable to explicitly report when stimuli in left and right hemifields were the same or different. Similarly, in a search task, the patient's reaction time was unaffected by distracters in the hemifield opposite the target whereas normals' response time was affected. Considering the dissociation between these two tasks, we conclude that the anterior commissure and/or the anterior corpus callosum contribute to interhemispheric interactions in the attentional selection of location.
Learn Faster Today Improve your study skills
Author information
Author/s: Afraz, S R (SR); Montaser-Kouhsari, L (L); Vaziri-Pashkam, M (M); Moradi, F (F);
Affiliation: School of Intelligent Systems, Institute for Studies in Theoretical Physics and Mathematics, Niavaran, PO Box 19395-5746, Tehran, Iran. srafraz@ipm.ir
Journal and publication information
Publication Type: Comparative Study; Journal Article
Journal: Neuropsychologia (Neuropsychologia), published in England. (Language: eng)
Reference: 2003-; vol 41 (issue 5) : pp 597-604
Dates: Created 2003/01/31; Completed 2003/04/17; Revised 2006/11/15;
PMID: 12559152, status: MEDLINE (last retrieval date: 11/6/2008)
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
External Links for this article (including full text providers, if available):
Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.
This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.
MeSH headings (categories)
This article was linked to the MESH Headings shown below.
|
|
Related articles
This article has not been indexed for related articles as yet, however you can still use the live related article search links below.
See a large map of 100+ related articles.