Linked Life Data

14960344

Source:http://linkedlifedata.com/resource/pubmed/id/14960344

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-2-12
pubmed:abstractText
When stimuli are presented in the left or right visual fields, hemispheric specialization for global and local processing in occipital areas is attenuated. Using functional magnetic resonance imaging, we investigated how this attenuation is compensated for when information must cross the corpus callosum to reach the areas specialized for global and local processing. We presented hierarchically nested letters (e.g. a large E made of smaller E's) to the right or the left visual hemifield while subjects fixated centrally. In half the trials, subjects indicated whether the global aspect and in the other half whether the local aspect of the stimulus matched a pre-specified target letter. Visual hemifield presentations showed the expected contralateral activations of occipital cortex. The main effects of locally or globally directed attention did not show any differential occipital activations, but the right anterior cingulate cortex was activated differentially during local processing. Region-of-interest-based analyses showed increased neural activity in left posterior occipital cortex during local processing when stimuli were presented in the left hemifield. During global processing with stimulus presentation to the right hemifield, the right posterior occipital cortex was activated. Activation of right anterior cingulate cortex during local processing is likely to reflect the suppression of global processing precedence in order to select correctly the local stimulus level. The activations in left (local) and right (global) occipital areas are likely to reflect the top-down augmentation of stimulus information that has been degraded by callosal crossing in order to access the hemisphere specialized for local or global processing.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
113-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
A functional magnetic resonance imaging study of local/global processing with stimulus presentation in the peripheral visual hemifields.
pubmed:affiliation
Institute of Medicine, Research Center Jülich, 52425 Jülich, Germany. s.lux@fz-juelich.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't