scholarly journals Alcohol reduces simultaneous contrast effects in human vision

2010 ◽  
Vol 2 (7) ◽  
pp. 208-208 ◽  
Author(s):  
K. Johnston ◽  
B. Timney ◽  
D. Leung ◽  
S. Khan
Keyword(s):  
Human Vision ◽  
Simultaneous Contrast ◽  
Contrast Effects

scholarly journals Gloss averaging and simultaneous contrast effects on real bicolored glossy surfaces

2015 ◽  
Vol 15 (12) ◽  
pp. 939
Author(s):  
Sabrina Hansmann-Roth ◽  
Pascal Mamassian ◽  
Sylvia Pont
Keyword(s):  
Simultaneous Contrast ◽  
Contrast Effects

Edge Computation in Human Vision: Anisotropy in the Combining of Oriented Filters

Perception ◽  
1995 ◽  
Vol 24 (6) ◽  
pp. 603-622 ◽  
Author(s):  
Tim S Meese ◽  
Tom C A Freeman
Keyword(s):  
Spatial Structure ◽  
Spatial Frequency ◽  
Human Vision ◽  
Contrast Effects ◽  
Compound Structure ◽  
Component Structure ◽  
Zero Crossings ◽  
Coding Scheme ◽  
Two Component ◽  
Sinusoidal Gratings

Above threshold, two superimposed sinusoidal gratings of the same spatial frequency (eg 1 cycle deg−1) and equal contrasts, and with orientations balanced around vertical, usually look like a compound structure containing vertical and horizontal edges. However, at large plaid angles (ie large differences between component orientations) and low plaid contrasts there is a tendency for the stimulus to appear as two overlapping gratings (component structure) with obliquely oriented edges. These dependencies of perceived spatial structure in plaids are incompatible with an edge-coding scheme that uses only circular filters to compute zero-crossings, but instead support the idea that different oriented filters can (compound percept) or cannot (component percept) be combined before edges are represented. Here, further evidence is presented in support of this hypothesis. Two-component plaid stimuli had plaid angles of 45° or 90°, and a range of plaid orientations (ie a range of orientations around which the plaid components were balanced). Observers indicated whether each stimulus was perceived as a compound or component structure for a range of plaid contrasts. In addition to angle and contrast effects, perceived spatial structure was also found to depend on plaid orientation: compound structures were perceived more often when the plaid components were balanced around the cardinal axes of the retina. It is suggested that the principles governing the combination of oriented-filter outputs might be learnt during the development of the visual system by using a Hebb-type rule: coactivated filters are more likely to combine their outputs when activated on future occasions. Given the prominence of vertical and horizontal orientations in a carpentered environment, this simple rule promotes a network that combines filters balanced around cardinal axes more readily than oblique axes, in agreement with the results.

scholarly journals Brief presentation enhances various simultaneous contrast effects

2017 ◽  
Vol 17 (4) ◽  
pp. 7 ◽  
Author(s):  
Sae Kaneko ◽  
Stuart Anstis ◽  
Ichiro Kuriki
Keyword(s):  
Simultaneous Contrast ◽  
Contrast Effects

scholarly journals Brief presentation enhances various simultaneous contrast effects

2016 ◽  
Vol 16 (12) ◽  
pp. 244
Author(s):  
Sae Kaneko ◽  
Stuart Anstis ◽  
Ichiro Kuriki
Keyword(s):  
Simultaneous Contrast ◽  
Contrast Effects

The Analogy between Stereo Depth and Brightness

Perception ◽  
1989 ◽  
Vol 18 (5) ◽  
pp. 601-614 ◽  
Author(s):  
Allen Brookes ◽  
Kent A Stevens
Keyword(s):  
Lateral Inhibition ◽  
Spatial Differentiation ◽  
Higher Order ◽  
Apparent Depth ◽  
Simultaneous Contrast ◽  
Original Signal ◽  
Contrast Effects ◽  
Spatial Derivatives

Apparent depth in stereograms exhibits various simultaneous-contrast and induction effects analogous to those reported in the luminance domain. This behavior suggests that stereo depth, like brightness, is reconstructed, ie recovered from higher-order spatial derivatives or differences of the original signal. The extent to which depth is analogous to brightness is examined. There are similarities in terms of contrast effects but dissimilarities in terms of the lateral inhibition effects traditionally attributed to underlying spatial-differentiation operators.

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