| Edges can eliminate the appearance of the contrast asynchrony. | |
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MedLine Citation:
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PMID: 20883337 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Recent work in the Shapiro laboratory has suggested that the visual response to changes in chromaticity/luminance can be separated from the visual response to changes in spatial contrast. Here, we examine how spatial edges affect the relative perceptual weighting of these two types of responses. In the experiments, we separate color from color contrast with a 'contrast asynchrony' stimulus in which the luminance of two identical rectangles varies sinusoidally over time. We use two different stimulus configurations: in one configuration, one rectangle is placed on a black background, and the other is placed on a white background; in the other configuration, the two rectangles are placed on a striped background (similar to Munker-White's background), with one rectangle set against a white stripe and the other against a black stripe. Experiment 1 documents that the rectangle placed on the solid white background appears to modulate out of phase with the rectangle placed on the solid black background, and that the two rectangles placed on the striped background appear to modulate in phase with each other. Experiment 2 measured the length the background stripes must be to shift from the perception of in-phase modulation to antiphase modulation (and vice versa). In the solid background configuration, the perceived shift from in-phase to antiphase occurred when edges above and below the rectangles were about 0.5°; and in the striped background configuration, the perceived shift from antiphase to in-phase occurred when the edges were < 10 min of arc. Experiment 3 showed that edges that could engender the perception of the contrast asynchrony in the striped background configuration had no effect on the perceived brightness of the bars. The results indicate that edges placed on opposite sides of the modulating field can inhibit the contrast response but do not necessarily affect the perceived brightness. |
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Authors:
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Arthur G Shapiro; Amber M Leaver |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Volume: 30 ISSN: 1475-1313 ISO Abbreviation: Ophthalmic Physiol Opt Publication Date: 2010 Sep |
Date Detail:
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Created Date: 2010-10-04 Completed Date: 2011-02-25 Revised Date: 2011-09-22 |
Medline Journal Info:
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Nlm Unique ID: 8208839 Medline TA: Ophthalmic Physiol Opt Country: England |
Other Details:
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Languages: eng Pagination: 534-44 Citation Subset: IM |
Copyright Information:
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© 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists. |
Affiliation:
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American University, Washington, DC 20016, USA. arthur.shapiro@american.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adolescent Color Perception / physiology* Contrast Sensitivity / physiology* Humans Optical Illusions / physiology Pattern Recognition, Visual / physiology* Photic Stimulation / methods Psychometrics Psychophysics Young Adult |
| Grant Support | |
ID/Acronym/Agency:
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F31 DC008921-01A1/DC/NIDCD NIH HHS; F31 DC008921-02/DC/NIDCD NIH HHS; F31 DC008921-03/DC/NIDCD NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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