scholarly journals A note on the influence of grouping on illusory contours

1999 ◽  
Vol 6 (2) ◽  
pp. 289-291 ◽  
Author(s):  
Stefano Vezzani
Keyword(s):  
Illusory Contours

Illusory Contours Can Arise in Dot Figures

Perception ◽  
1978 ◽  
Vol 7 (2) ◽  
pp. 191-194 ◽  
Author(s):  
John M Kennedy ◽  
Colin Ware
Keyword(s):  
Contrast Effects ◽  
Illusory Contours ◽  
Good Figure

Frisby and Clatworthy have suggested that subjective contours depend on special contrast effects acting at the tips of lines and at right angles to the lines. Their suggestion depends in part on the absence of such contours in dot figures. However, if the dots are grouped regularly and make a ‘good figure’, strong subjective contours appear, including a pattern comparable to Kanizsa's triangle. The kind of contrast explanation required for these figures would be one in which individual dots create small contrast effects which are only manifest in perception when the effects are grouped together, by Gestalt form indicators, overlap cues, or the like.

Amodal Completion and the Perception of Depth without Binocular Correspondence

Perception ◽  
10.1068/p3305 ◽  
2002 ◽  
Vol 31 (9) ◽  
pp. 1037-1045 ◽  
Author(s):  
Benoit A Bacon ◽  
Pascal Mamassian
Keyword(s):  
Amodal Completion ◽  
Correspondence Problem ◽  
Illusory Contours ◽  
Binocular Matching ◽  
Partially Occluded ◽  
Global Surface

Half-occlusions and illusory contours have recently been used to show that depth can be perceived in the absence of binocular correspondence and that there is more to stereopsis than solving the correspondence problem. In the present study we show a new way for depth to be assigned in the absence of binocular correspondence, namely amodal completion. Although an occluder removed all possibility of direct binocular matching, subjects consistently assigned the correct depth (convexity or concavity) to partially occluded ‘folded cards’ stimuli. Our results highlight the importance of more global, surface-based processes in stereopsis.

Infants Perceive Three-Dimensional Subjective Contours

Perception ◽  
2018 ◽  
Vol 47 (12) ◽  
pp. 1153-1165 ◽  
Author(s):  
Michael Kavšek ◽  
Stephanie Braun
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Illusory Effect ◽  
Horizontal Disparity ◽  
Illusory Contours ◽  
Kanizsa Figure

The addition of crossed horizontal disparity enhances the clarity of illusory contours compared to pictorial illusory contours and illusory contours with uncrossed horizontal disparity. Two infant-controlled habituation–dishabituation experiments explored the presence of this effect in infants 5 months of age. Experiment 1 examined whether infants are able to distinguish between a Kanizsa figure with crossed horizontal disparity and a Kanizsa figure with uncrossed horizontal disparity. Experiment 2 tested infants for their ability to differentiate between a Kanizsa figure with crossed horizontal disparity and a two-dimensional Kanizsa figure. The results provided evidence that the participants perceived the two- and the three-dimensional illusory Kanizsa contour, the illusory effect in which was strengthened by the addition of crossed horizontal disparity.

scholarly journals Form, set organization and visual attention in illusory contours perception

Psihologija ◽  
2009 ◽  
Vol 42 (2) ◽  
pp. 239-254 ◽  
Author(s):  
Vasilije Gvozdenovic
Keyword(s):  
Visual Search ◽  
Visual Attention ◽  
Experimental Psychology ◽  
Illusory Contours ◽  
Target Figure ◽  
Simple Detection ◽  
The Way

Laboratory of Experimental Psychology, University of Belgrade The aim of the study was the investigation of form, spatial set organization and visual attention in visual search of illusory contours. Three visual search experiments were conducted. In the first experiment, where the simple detection procedure was used, subject's task was to detect square among vertical and horizontal lines. Other experiments investigated visual search of illusory contours in four different set organizations. Introduction of set organization was the way of manipulation of target's eccentricity among other elements. Analysis showed different type of search of the regular and the illusory square figure. The search profile of the regular square proved to be parallel, while all the searches of the illusory squares remained serial. Set organization had important role in visual search of illusory contours. Regardless of serial profile, visual search was faster in cases where target figure was more salient due to the background elements organization.

Insect perception of illusory contours

1992 ◽  
Vol 337 (1279) ◽  
pp. 59-64 ◽  
Keyword(s):  
Human Visual System ◽  
Illusory Contour ◽  
Optic Lobe ◽  
Insect Vision ◽  
Local Contrast ◽  
Fault Line ◽  
Illusory Contours ◽  
Striped Pattern ◽  
Processing Power ◽  
As If

The human visual system sees an illusory contour where there is a fault line across a regular striped pattern. We demonstrate that bees respond as if they see the same illusory contour. There is also a type of neuron in the lobula of the dragonfly optic lobe which responds directionally to motion of the illusory contour as if to an edge or line. Apparently insects have a mechanism that sees illusory contours and therefore assists in the demarcation of edges and objects at places where local contrast falls to zero at an edge, or where one textured object partially obscures another. These results suggest that insect vision, although spatially crude and low in processing power, sees separate objects by similar mechanisms to our own.

scholarly journals Erratum to: Illusory contours and stereo depth

1975 ◽  
Vol 17 (1) ◽  
pp. 96-96
Author(s):  
R. L. Gregory ◽  
J. P. Harris
Keyword(s):  
Illusory Contours
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