Document Detail


Edges, colour and awareness in blindsight.
MedLine Citation:
PMID:  20171122     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
It remains unclear what is being processed in blindsight in response to faces, colours, shapes, and patterns. This was investigated in two hemianopes with chromatic and achromatic stimuli with sharp or shallow luminance or chromatic contrast boundaries or temporal onsets. Performance was excellent only when stimuli had sharp spatial boundaries. When discrimination between isoluminant coloured Gaussians was good it declined to chance levels if stimulus onset was slow. The ability to discriminate between instantaneously presented colours in the hemianopic field depended on their luminance, indicating that wavelength discrimination totally independent of other stimulus qualities is absent. When presented with narrow-band colours the hemianopes detected a stimulus maximally effective for S-cones but invisible to M- and L-cones, indicating that blindsight is mediated not just by the mid-brain, which receives no S-cone input, or that the rods contribute to blindsight. The results show that only simple stimulus features are processed in blindsight.
Authors:
Iona Alexander; Alan Cowey
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-02-18
Journal Detail:
Title:  Consciousness and cognition     Volume:  19     ISSN:  1090-2376     ISO Abbreviation:  Conscious Cogn     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-05-07     Completed Date:  2010-08-03     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9303140     Medline TA:  Conscious Cogn     Country:  United States    
Other Details:
Languages:  eng     Pagination:  520-33     Citation Subset:  IM    
Copyright Information:
2010 Elsevier Inc. All rights reserved.
Affiliation:
University of Oxford, Department of Experimental Psychology, South Parks Road, Oxford OX13UD, UK. iona.alexander@psy.ox.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Awareness / physiology*
Color
Color Perception / physiology*
Color Perception Tests
Discrimination (Psychology) / physiology
Form Perception / physiology*
Hemianopsia / physiopathology*
Humans
Photic Stimulation
Time Factors
Grant Support
ID/Acronym/Agency:
//Medical Research Council

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


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