Linked Life Data

10493756

Source:http://linkedlifedata.com/resource/pubmed/id/10493756

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1999-10-14
pubmed:abstractText
Illusory contours (perceived edges that exist in the absence of local stimulus borders) demonstrate that perception is an active process, creating features not present in the light patterns striking the retina. Illusory contours are thought to be processed using mechanisms that partially overlap with those of "real" contours, but questions about the neural substrate of these percepts remain. Here, we employed functional magnetic resonance imaging to obtain physiological signals from human visual cortex while subjects viewed different types of contours, both real and illusory. We sampled these signals independently from nine visual areas, each defined by retinotopic or other independent criteria. Using both within- and across-subject analysis, we found evidence for overlapping sites of processing; most areas responded to most types of contours. However, there were distinctive differences in the strength of activity across areas and contour types. Two types of illusory contours differed in the strength of activation of the retinotopic areas, but both types activated crudely retinotopic visual areas, including V3A, V4v, V7, and V8, bilaterally. The extent of activation was largely invariant across a range of stimulus sizes that produce illusory contours perceptually, but it was related to the spatial frequency of displaced-grating stimuli. Finally, there was a striking similarity in the pattern of results for the illusory contour-defined shape and a similar shape defined by stereoscopic depth. These and other results suggest a role in surface perception for this lateral occipital region that includes V3A, V4v, V7, and V8.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8560-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
The representation of illusory and real contours in human cortical visual areas revealed by functional magnetic resonance imaging.
pubmed:affiliation
Massachusetts General Hospital Nuclear Magnetic Resonance Center, Charlestown, Massachusetts 02129, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't