Document Detail


The effects of adaptation and masking on incremental thresholds for contrast.
MedLine Citation:
PMID:  8266646     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Using a temporal two-alternative forced-choice procedure, we measured thresholds for detecting increments in contrast of a 2 c/deg vertical grating at a wide range of pedestal contrasts, (1) before and after adapting to a grating of the same orientation and spatial frequency, and (2) in the presence of superimposed masks that varied in either orientation or spatial frequency. The adapting grating and all masks were of fixed 40% contrast. The results show that prior adaptation and concurrent masking have qualitatively similar effects on incremental thresholds; both raise threshold at low pedestal contrasts and leave them unaltered at higher contrasts. But masks have greater effects than adaptors, the effect of an orthogonal mask, or one two octaves higher in spatial frequency, being about the same as a parallel adaptor of the same spatial frequency as the pedestal grating. The results are explained by a model of Ross and Speed [(1991) Proceedings of the Royal Society of London B, 246, 61-69] that assumes that masks and adaptors both reposition the transducer function of contrast sensitive mechanisms and that masks, but not adaptors, also stimulate the detecting mechanism.
Authors:
J Ross; H D Speed; M J Morgan
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Vision research     Volume:  33     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  1993 Oct 
Date Detail:
Created Date:  1994-01-25     Completed Date:  1994-01-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  2051-6     Citation Subset:  IM    
Affiliation:
Department of Psychology, University of Western Australia, Nedlands.
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Ocular / physiology*
Contrast Sensitivity / physiology*
Humans
Perceptual Masking / physiology*
Sensory Thresholds

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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