Document Detail


Differential roles of contrast polarity reveal two streams of second-order visual processing.
MedLine Citation:
PMID:  17555787     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Humans can easily segregate texture regions based on differences in contrast, orientation, and contrast polarity. It has been suggested that these abilities can be inclusively modeled by 2nd-order visual mechanisms that detect changes in the half-wave rectified outputs of orientation-selective filters. Using a subthreshold-summation paradigm, however, we show that modulations of contrast polarity are detected by mechanisms that pool signals of different orientations while modulations of orientation are detected by mechanisms that pool signals of different contrast polarities. The results support the existence of two streams of 2nd-order processing, one that receives the full-wave rectified inputs from oriented filters, the other separate half-wave rectified outputs from on-center and off-center filters pooled across all orientations. The two-stream model is shown to predict the perceptual effects of changes to the skewness statistics of natural-image textures, and to solve a contradiction among previous data concerning the detection of contrast modulation.
Authors:
Isamu Motoyoshi; Frederick A A Kingdom
Related Documents :
12607037 - The antennal system and cockroach evasive behavior. i. roles for visual and mechanosens...
9509737 - Acoustic correlates of perceived versus actual sexual orientation in men's speech.
16489857 - Tilt aftereffect for texture edges is larger than in matched subjective edges, but both...
9340077 - Translating between orthogonally oriented stimulus and response arrays in four-choice r...
3612237 - Sinusoidal movement of a grating across the monkey's fingerpad: temporal patterns of af...
10212427 - Temporal integration and multiple looks, revisited: weights as a function of time.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-06-06
Journal Detail:
Title:  Vision research     Volume:  47     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-06-19     Completed Date:  2007-08-14     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  England    
Other Details:
Languages:  eng     Pagination:  2047-54     Citation Subset:  IM    
Affiliation:
Human and Information Science Laboratory, NTT Communication Science Laboratories, NTT 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan. motoyosi@apollo3.brl.ntt.co.jp
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Contrast Sensitivity / physiology*
Humans
Models, Psychological
Pattern Recognition, Visual / physiology*
Photic Stimulation / methods
Psychophysics
Sensory Thresholds / physiology
Visual Pathways / physiology*

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


Previous Document:  Microarray analysis of glial cells resistant to JCV infection suggests a correlation between viral i...
Next Document:  Kinetic analysis of palladium(II) adsorption process on condensed-tannin gel based on redox reaction...