| Spatial-frequency bands in complex visual stimuli: American Sign Language. | |
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MedLine Citation:
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PMID: 3404311 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Dynamic images of individual signs of American Sign Language (ASL) with a resolution of 96 X 64 pixels were bandpass filtered in adjacent frequency bands. Intelligibility was determined by testing deaf subjects fluent in ASL. The following results were obtained. (1) By iteratively varying the center frequencies and bandwidths of the spatial bandpass filters, it was possible to divide the original signal into four different component bands of high intelligibility. (2) The measured temporal-frequency spectrum was approximately the same in all bands. (3) The masking of signals in band i by noise in band j was found to be inversely proportional to log [f signal/f noise]. At constant performance, the ratio of root-mean-square signal amplitude to noise amplitude, s/n, was the same for bands 2,3, and 4 and higher for band 1. (4) When weak signals i and j were added linearly, there was a slight intelligibility advantage for signals in the same band (i = j) compared with signals in adjacent bands and for signals in adjacent bands compared with signals in distant bands. |
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Authors:
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T R Riedl; G Sperling |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
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Title: Journal of the Optical Society of America. A, Optics and image science Volume: 5 ISSN: 0740-3232 ISO Abbreviation: J Opt Soc Am A Publication Date: 1988 Apr |
Date Detail:
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Created Date: 1988-09-13 Completed Date: 1988-09-13 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8402086 Medline TA: J Opt Soc Am A Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 606-16 Citation Subset: IM; S |
Affiliation:
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Department of Psychology, New York University, New York 10003. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Humans Manual Communication* Mathematics Perceptual Masking Sign Language* Statistics as Topic Time Factors Visual Perception / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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