Linked Life Data

10234853

Source:http://linkedlifedata.com/resource/pubmed/id/10234853

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-6-7
pubmed:abstractText
The sensitivity of the visual system depends on ambient illumination: Sensitivity is reduced in the presence of a bright, uniform background. We asked how sensitivity is adjusted when the background is spatially detailed and therefore contains both luminance peaks and troughs in the neighborhood of a foreground object. A test flash was superimposed on a static sinusoidal grating. As the grating's spatial frequency increased, sensitivity for flash detection declined, regardless of whether the flash was superimposed on a peak or a trough of the grating. We studied the mechanisms underlying this loss of sensitivity by delivering the test stimulus through one eye and the background through the other. The conclusion is that three mechanisms are involved. Luminance adaptation and a masking process adjust sensitivity at low- and mid-range spatial frequencies, respectively. The third mechanism, a contrast gain control, is localized (it occurs at spatial frequencies approaching the limit for resolution) and fast (complete in half a second), and it results from early processing in the visual pathway (it is absent during dichoptic viewing). This local adjustment of sensitivity may help to protect the clarity of even the smallest details in the visual scene.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1084-7529
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
979-86
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Visual sensitivity in the presence of a patterned background.
pubmed:affiliation
Department of Biomedical Sciences, University of Sydney, Lidcombe, New South Wales, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't