Document Detail


Metacontrast masking within and between visual channels: effects of orientation and spatial frequency contrasts.
MedLine Citation:
PMID:  20884561     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
We measured the strength and optimal target-mask onset asynchrony (SOA(max)) of metacontrast masking using Gabor patches as targets and sinusoidal rings with Gaussian envelopes as masks. We varied spatial frequencies (f) between 0.5 and 8 cpd to manipulate the degree to which spatial frequency channels in the visual system are triggered. By varying spatial frequencies as well as spatial frequency contrast (Δf) between target and mask, we measured the properties of inter- as well as intra-channel inhibition. We found that an increase of the mask's spatial frequency decreased its effectiveness but did not change its SOA(max). When orientation contrast was introduced between targets and masks with the same spatial frequency, SOA(max) increased with orientation contrast. An effect of orientation contrast was not observed with low spatial frequency-on-high spatial frequency masking, indicating that orientation selectivity is a unique feature of within-channel masking. Spatial frequency contrast affects SOA(max) and effectiveness in an asymmetric fashion: low-on-high masking is strong and yields a longer SOA(max), compared to low-on-low and high-on-high masking; high-on-low masking is ineffective.
Authors:
Maximilian Bruchmann; Bruno G Breitmeyer; Christo Pantev
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-06-01
Journal Detail:
Title:  Journal of vision     Volume:  10     ISSN:  1534-7362     ISO Abbreviation:  J Vis     Publication Date:  2010  
Date Detail:
Created Date:  2010-10-04     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101147197     Medline TA:  J Vis     Country:  United States    
Other Details:
Languages:  eng     Pagination:  12     Citation Subset:  IM    
Affiliation:
Institute for Biomagnetism and Biosignal Analysis, University of Muenster, Germany. Maximilian.Bruchmann@uni-muenster.de
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