scholarly journals Surface and motion integration determined by luminance contrast polarity

2004 ◽  
Vol 4 (8) ◽  
pp. 888-888
Author(s):  
Y. Su ◽  
T. Leng ◽  
Z. J. He
Keyword(s):  
Luminance Contrast ◽  
Contrast Polarity ◽  
Motion Integration

scholarly journals The integration of local chromatic motion signals is sensitive to contrast polarity

2011 ◽  
Vol 28 (3) ◽  
pp. 239-246 ◽  
Author(s):  
SOPHIE M. WUERGER ◽  
ALEXA RUPPERTSBERG ◽  
STEPHANIE MALEK ◽  
MARCO BERTAMINI ◽  
JASNA MARTINOVIC
Keyword(s):  
Random Motion ◽  
Coherent Motion ◽  
Global Motion ◽  
Local Motion ◽  
Chromatic Contrast ◽  
Motion Direction ◽  
Contrast Polarity ◽  
Motion Integration ◽  
Integration Mechanisms ◽  
Contrast Thresholds

AbstractGlobal motion integration mechanisms can utilize signals defined by purely chromatic information. Is global motion integration sensitive to the polarity of such color signals? To answer this question, we employed isoluminant random dot kinematograms (RDKs) that contain a single chromatic contrast polarity or two different polarities. Single-polarity RDKs consisted of local motion signals with either a positive or a negative S or L–M component, while in the different-polarity RDKs, half the dots had a positive S or L–M component, and the other half had a negative S or L–M component. In all RDKs, the polarity and the motion direction of the local signals were uncorrelated. Observers discriminated between 50% coherent motion and random motion, and contrast thresholds were obtained for 81% correct responses. Contrast thresholds were obtained for three different dot densities (50, 100, and 200 dots). We report two main findings: (1) dependence on dot density is similar for both contrast polarities (+S vs. −S, +LM vs. −LM) but slightly steeper for S in comparison to LM and (2) thresholds for different-polarity RDKs are significantly higher than for single-polarity RDKs, which is inconsistent with a polarity-blind integration mechanism. We conclude that early motion integration mechanisms are sensitive to the polarity of the local motion signals and do not automatically integrate information across different polarities.

Geometrical Errors Are the Cost of Maintaining the Luminance Contrast Polarity

2017 ◽  
Author(s):  
Sergio Roncato
Keyword(s):  
Luminance Contrast ◽  
Contrast Polarity ◽  
Geometrical Errors ◽  
Visual Completion ◽  
Visual Organization ◽  
Preferential Rule ◽  
The Cost

The visual completion is the result of the integration of fragmented contours. The contrast polarity (or contrast sign) may affect this interpolation by strengthening the completion in a direction where the contrast polarity is preserved. This chapter illustrates some manifestations of these phenomena: the alteration of the alignment of the visual units and the illusory tilt of more complex visual organization. The occurrence of basic distorting effects underlying classic illusions—such as the Frazer illusion—is discussed. It is noted that the role of the contrast polarity rule in representing a “preferential” rule does not preclude other possibilities, such as edges completion, although it renders the contour detectable to a lesser degree.

scholarly journals The butterfly Papilio xuthus detects visual motion using chromatic contrast

2015 ◽  
Vol 11 (10) ◽  
pp. 20150687 ◽  
Author(s):  
Finlay J. Stewart ◽  
Michiyo Kinoshita ◽  
Kentaro Arikawa
Keyword(s):  
Motion Detection ◽  
Visual Motion ◽  
Luminance Contrast ◽  
Head Movements ◽  
Motion Vision ◽  
Measuring Head ◽  
Chromatic Contrast ◽  
Contrast Polarity ◽  
Papilio Xuthus ◽  
Colour Patterns

Many insects’ motion vision is achromatic and thus dependent on brightness rather than on colour contrast. We investigate whether this is true of the butterfly Papilio xuthus , an animal noted for its complex retinal organization, by measuring head movements of restrained animals in response to moving two-colour patterns. Responses were never eliminated across a range of relative colour intensities, indicating that motion can be detected through chromatic contrast in the absence of luminance contrast. Furthermore, we identify an interaction between colour and contrast polarity in sensitivity to achromatic patterns, suggesting that ON and OFF contrasts are processed by two channels with different spectral sensitivities. We propose a model of the motion detection process in the retina/lamina based on these observations.

A Test for Contrast-Polarity Selectivity in the Tilt Aftereffect

Perception ◽  
1979 ◽  
Vol 8 (5) ◽  
pp. 523-528 ◽  
Author(s):  
Svein Magnussen ◽  
Wolfgang Kurtenbach
Keyword(s):  
Luminance Contrast ◽  
Tilt Aftereffect ◽  
Contrast Polarity

The tilt aftereffect (TAE) was studied with adapting and test stimuli consisting of black or white bars (experiment 1), and of luminance edges (experiment 2). Both experiments failed to demonstrate selectivity of the TAE to the polarity of luminance contrast.

scholarly journals The effect of nearby luminance contrast polarity on color boundary localization

1995 ◽  
Vol 35 (19) ◽  
pp. 2767-2771 ◽  
Author(s):  
Harold H. Greene ◽  
James M. Brown
Keyword(s):  
Luminance Contrast ◽  
Contrast Polarity

scholarly journals Why is the tilt after-effect selective to local but not global luminance-contrast polarity?

2013 ◽  
Vol 13 (9) ◽  
pp. 712-712
Author(s):  
E. Gheorghiu ◽  
J. Bell ◽  
F. A. A. Kingdom
Keyword(s):  
Luminance Contrast ◽  
Contrast Polarity ◽  
After Effect

scholarly journals Spatial structure, contrast polarity and motion integration

2000 ◽  
Vol 40 (15) ◽  
pp. 2037-2045 ◽  
Author(s):  
Maarten J van der Smagt ◽  
Esther C.W Breij ◽  
Wim A van de Grind
Keyword(s):  
Spatial Structure ◽  
Contrast Polarity ◽  
Motion Integration

scholarly journals Dependence of perceptual saccadic suppression on peri-saccadic image flow properties and luminance contrast polarity

2021 ◽  
Vol 21 (9) ◽  
pp. 2282
Author(s):  
Matthias Philipp Baumann ◽  
Saad Idrees ◽  
Thomas Münch ◽  
Ziad Hafed
Keyword(s):  
Luminance Contrast ◽  
Saccadic Suppression ◽  
Flow Properties ◽  
Contrast Polarity ◽  
Image Flow

scholarly journals Dependence of perceptual saccadic suppression on peri-saccadic image flow properties and luminance contrast polarity

2021 ◽  
Vol 21 (5) ◽  
pp. 15
Author(s):  
Matthias P. Baumann ◽  
Saad Idrees ◽  
Thomas A. Münch ◽  
Ziad M. Hafed
Keyword(s):  
Luminance Contrast ◽  
Saccadic Suppression ◽  
Flow Properties ◽  
Contrast Polarity ◽  
Image Flow
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