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Visual sensitivity to spatially sampled modulation in human observersThresholds were measured for detecting spatial luminance modulation in regular lattices of visually discrete dots. Thresholds for modulation of a lattice are generally higher than the corresponding threshold for modulation of a continuous field, and the size of the threshold elevation, which depends on the spacing of the lattice elements, can be as large as a one log unit. The largest threshold elevations are seen when the sample spacing is 12 min arc or greater. Theories based on response compression cannot explain the further observation that the threshold elevations due to spatial sampling are also dependent on modulation frequency: the greatest elevations occur with higher modulation frequencies. The idea that this is due to masking of the modulation frequency by the spatial frequencies in the sampling lattice is considered.
Document ID
19910051320
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Mulligan, Jeffrey B.
(NASA Ames Research Center Moffett Field; California, University, La Jolla, United States)
Macleod, Donald I. A.
(California, University La Jolla, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1991
Publication Information
Publication: Vision Research
Volume: 31
Issue: 5 19
ISSN: 0042-6989
Subject Category
Behavioral Sciences
Accession Number
91A35943
Funding Number(s)
CONTRACT_GRANT: NIH-EY-01711
Distribution Limits
Public
Copyright
Other

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