| The perception and discrimination of speed in complex motion. | |
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MedLine Citation:
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PMID: 10343803 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Random dot kinematograms were used to simulate radial, rotational and spiral optic flow. The stimuli were designed so that, while dot speed increased linearly with distance from the centre of the display, the density of dots remained uniform throughout their presentation. In two experiments, subjects were required to perform a temporal 2AFC speed discrimination task. Experiment 1 measured the perceived speed of a range of optic flow patterns against a rotational comparison stimulus. Radial motions were found to appear faster than rotations by approximately 10%, with a smaller but significant effect for spirals. Experiment 2 measured discrimination thresholds for pairs of similar optic flow stimuli identical in all respects except mean speed. No consistent differences were observed between the speed discrimination thresholds of radial, rotational and spiral motions and a control stimulus with the same speed profile in which motion followed fixed random trajectories. The perceived speed results are interpreted in terms of a model satisfying constraints on motion-in-depth and object rigidity, while speed discrimination appears to be based upon the pooled responses of elementary motion detectors. |
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Authors:
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C W Clifford; S A Beardsley; L M Vaina |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Vision research Volume: 39 ISSN: 0042-6989 ISO Abbreviation: Vision Res. Publication Date: 1999 Jun |
Date Detail:
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Created Date: 1999-06-14 Completed Date: 1999-06-14 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0417402 Medline TA: Vision Res Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 2213-27 Citation Subset: IM; S |
Affiliation:
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Department of Biomedical Engineering, Boston University, MA 02215, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Differential Threshold
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physiology Female Humans Mathematics Models, Neurological Motion Perception / physiology* Psychophysics Rotation Time Factors |
| Grant Support | |
ID/Acronym/Agency:
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EY-2R01-0781-08/EY/NEI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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