Linked Life Data

9797941

Source:http://linkedlifedata.com/resource/pubmed/id/9797941

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1998-11-10
pubmed:abstractText
Previous experimental studies (e.g. Kovacs I, Julesz B. Nature (London) 1994; 370:644-646) have found enhanced contrast sensitivity at medial locations, supporting theoretical speculations that the visual system represents simple spatial regions by their medial axes. The core model (Burbeck CA, Pizer SM. Vis Res 1995;35:1917-1930) hypothesizes that the medial representation arises in a scale-specific way: the scale is determined by local object width, and it controls the resolution at which the medial locus and object width are encoded. Here we look for further evidence for a medial representation and test the idea that the resolution of the axis depends on object width. A new experimental paradigm was developed to infer sensitivity to position within individual figural regions, using circles as the figural regions. A probe dot was presented within a circle along a diameter at one location in one temporal interval and at a slightly different location on that diameter in a second temporal interval. The observer's task was to report the direction in which the probe dot had been displaced. Position discrimination thresholds were calculated and compared to two-dot separation discrimination thresholds. Data were obtained for two circle sizes. It was found that positional sensitivity was strongly enhanced near the center of the circle, and it was enhanced in a scale-dependent way. The results were tested against a scaled medial (core) model and against models assuming no medial representation. The core model was better able to account for the results.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0042-6989
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1947-59
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Scaled medial axis representation: evidence from position discrimination task.
pubmed:affiliation
Psychology Department, University of North Carolina, Chapel Hill 27599, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.