Linked Life Data

7262224

Source:http://linkedlifedata.com/resource/pubmed/id/7262224

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
1981-10-14
pubmed:abstractText
Detection of broadband, aperiodic stimuli (edges) was investigated in normal observers, and in observers with abnormal visual experience which resulted in amblyopia. The spatial properties of the mechanisms used to detect an edge were investigated by a method of subthreshold addition. The method involved the determination of the threshold contrast for detecting an edge in the presence of a subthreshold line at various distances from the edge. In normal eyes, the one dimensional sensitivity profile of the edge detecting mechanism was: (1) approximately antisymmetric, (2) very localized, with sensitivity changes restricted to +/- 6'--8' on either side of the edge, and (3) phase dependent, showing an abrupt change in sign between +/- 1.5'. The sensitivity profiles of the amblyopic eyes were also approximately antisymmetric and showed the same steep rate of change from plus to minus as the fellow (nonamblyopic) eyes. However, in every case, the spatial extent of the profile was much broader than that of the nonamblyopic eyes. In normal eyes, the narrowest edge sensitivity profile was associated with the fovea; however, in two amblyopes with eccentric fixation, the narrowest edge sensitivity profile coincided with the locus of eccentric fixation. Moreover, the grating sensitivity function of the edge detecting mechanism of the amblyopic eye was similar to that of the non-amblyopic eye, but was shifted toward lower spatial frequencies. Control experiments show that these results are not accounted for on the basis of optics, eccentric fixation, or abnormal eye movements. The findings are discussed in terms of current models for the detection of aperiodic stimuli, and in the context of animal models of amblyopia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
270-80
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Edge sensitive mechanisms in humans with abnormal visual experience.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.