Linked Life Data

18675841

Source:http://linkedlifedata.com/resource/pubmed/id/18675841

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2008-9-22
pubmed:abstractText
The study of shape processing in the human visual system has frequently employed radial frequency (RF) patterns as conveniently manipulable stimuli. This study uses an adaptation paradigm to investigate how local shape information is sampled in the processing of RF contour shapes. Experiment 1 measured thresholds for detecting a fixed mean radius RF contour following adaptation to RF patterns which, in separate conditions, varied in mean radius and radial frequency. Results reveal that, adaptation is strongly tuned for RF over a range of pattern radii, but is not tuned for the number of cycles of radial modulation per visual degree of contour length; a characteristic that changes with both radius and radial frequency. Experiment 2 manipulated the polar angle separation on the fronto-parallel plane between curvature features on a fixed RF by foreshortening the pattern appearance (consistent with a rotation in depth) and shows that RF shape processing is tuned for fronto-parallel separation angles between curvature features. Results were near identical when a stereo rotation cue was added to the perspective modified RF. In the second part of Experiment 2 we showed that RF shape adaptation is also tuned for the polar angular extent of the curvature represented by the lobe at that angle. Collectively, our results indicate that the polar angle at which local curvature features appear, in addition to the angular extent of the curvature feature at that location, are both critical parameters for coding specific RF shapes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1878-5646
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2293-301
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Radial frequency adaptation suggests polar-based coding of local shape cues.
pubmed:affiliation
School of Psychology, The University of Western Australia, 35 Stirling Highway, Crawley 6009, WA, Australia. Jason.bell@mail.mcgill.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't