Hemispheric specialization for global and local processing: the effect of stimulus category.

Détails

ID Serval
serval:BIB_8B8D2FA20E39
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Hemispheric specialization for global and local processing: the effect of stimulus category.
Périodique
Proceedings of the Royal Society of London B Biological Sciences
Auteur(s)
Fink G.R., Marshall J.C., Halligan P.W., Frith C.D., Frackowiak R.S., Dolan R.J.
ISSN
0962-8452 (Print)
ISSN-L
0962-8452
Statut éditorial
Publié
Date de publication
1997
Volume
264
Numéro
1381
Pages
487-494
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Résumé
Neuropsychological evidence indicates that the global aspect of complex visual scenes is preferentially processed by the right hemisphere, and local aspects are preferentially processed by the left hemisphere. Using letter-based hierarchical stimuli (Navon figures), we recently demonstrated, in a directed-attention task, lateralized neural activity (assessed by positron emission tomography) in the left prestriate cortex during local processing, and in the right prestriate cortex during global processing. Furthermore, temporal-parietal cortex was critically activated bilaterally in a divided-attention task that involved varying the number of target switches between local and global levels of letter-based hierarchical stimuli. Little is known about whether such stimulus categories influence such hemispheric lateralization. We now present data on brain activity, derived from positron emission tomography, in normal subjects scanned during either local or global processing of object-based hierarchical stimuli. We again observe attentional modulation of neural activity in prestriate cortex. There is now greater right-sided activation for local processing and greater left-sided activation for global processing, which is the opposite of that seen with letter-based stimuli. The results suggest that the relative differential hemispheric activations in the prestriate areas during global and local processing are modified by stimulus category.
Mots-clé
Adult, Brain/physiology, Cerebrovascular Circulation, Humans, Male, Visual Pathways/physiology, Visual Perception/physiology
Pubmed
Web of science
Création de la notice
16/09/2011 17:44
Dernière modification de la notice
03/03/2018 19:12
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