The role of edges and line-ends in illusory contour formation

Illusory contours can be induced along directions approximately colinear to edges or approximately perpendicular to the ends of lines. Using a rating scale procedure we explored the relation between the two types of inducers by systematically varying the thickness of inducing elements to result in varying amounts of "edge-like" or "line-like" induction. Inducers for our illusory figures consisted of concentric rings with arcs missing. Observers judged the clarity and brightness of illusory figures as the number of arcs, their thicknesses, and spacings were parametrically varied. Degree of clarity and amount of induced brightness were both found to be inverted-U functions of the number of arcs. These results mandate that any valid model of illusory contour formation must account for interference effects between parallel lines or between those neural units responsible for completion of boundary signals in directions perpendicular to the ends of thin lines. Line width was found to have an effect on both clarity and brightness, a finding inconsistent with those models which employ only completion perpendicular to inducer orientation.

[1]  L. Finkel,et al.  Integration of distributed cortical systems by reentry: a computer simulation of interactive functionally segregated visual areas , 1989, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[2]  J. Kennedy.  Illusory Contours Not Due to Completion , 1978, Perception.

[3]  N. Weisstein,et al.  A phantom-motion aftereffect. , 1977, Science.

[4]  R. von der Heydt,et al.  Mechanisms of contour perception in monkey visual cortex. II. Contours bridging gaps , 1989, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[5]  Joel S. Warm,et al.  The Role of Illumination Level in the Strength of Subjective Contours , 1987 .

[6]  A. T. Smith,et al.  Motion aftereffect with subjective contours , 1979, Perception & psychophysics.

[7]  M. White,et al.  A New Effect of Pattern on Perceived Lightness , 1979, Perception.

[8]  F. Kingdom,et al.  White's effect: A dual mechanism , 1989, Vision Research.

[9]  P. Kellman,et al.  Perception of Partly Occluded Objects and Illusory Figures : Evidence for an Identity Hypothesis , 2004 .

[10]  H Wallach,et al.  The role of memory in perceiving subjective contours , 1988, Perception & psychophysics.

[11]  R. Tennant,et al.  Inhibition of leukaemia virus replication by polyadenylic acid. , 1972, Nature: New biology.

[12]  T F Shipley,et al.  The role of discontinuities in the perception of subjective figures , 1990, Perception & psychophysics.

[13]  G. Kanizsa,et al.  Organization in Vision: Essays on Gestalt Perception , 1979 .

[14]  G. Westheimer,et al.  Spatial location and hyperacuity: The centre/surround localization contribution function has two substrates , 1985, Vision Research.

[15]  R. Over,et al.  Orientation Masking and the Tilt Illusion with Subjective Contours , 1977, Perception.

[16]  R. von der Heydt,et al.  Illusory contours and cortical neuron responses. , 1984, Science.

[17]  J. Kennedy.  Illusory Contours and the Ends of Lines , 1978, Perception.

[18]  T. Watanabe,et al.  Are Illusory Contours a Cause or a Consequence of Apparent Differences in Brightness and Depth in the Kanizsa Square? , 1988, Perception.

[19]  G. Westheimer,et al.  Spatial location and hyperacuity: flank position within the centre and surround zones. , 1985, Spatial vision.

[20]  M. Jory.  Increment Thresholds in Illusory Contour Line Patterns , 1987 .

[21]  W. L. Brigner,et al.  Subjective Contour: Apparent Depth or Simultaneous Brightness Contrast? , 1974, Perceptual and motor skills.

[22]  Stephen Grossberg,et al.  The Role of Illusory Contours in Visual Segmentation , 1987 .

[23]  G. Minguzzi,et al.  Anomalous Figures and the Tendency to Continuation , 1987 .

[24]  V S Ramachandran,et al.  Capture of stereopsis and apparent motion by illusory contours , 1986, Perception & psychophysics.

[25]  P. Kellman,et al.  A theory of visual interpolation in object perception , 1991, Cognitive Psychology.

[26]  S Petry,et al.  Evidence for Independent Processing of Subjective Contour Brightness and Sharpness , 1991, Perception.

[27]  P. Kellman,et al.  Strength of visual interpolation depends on the ratio of physically specified to total edge length , 1992, Perception & psychophysics.

[28]  David J. Field,et al.  Contour integration by the human visual system: Evidence for a local “association field” , 1993, Vision Research.

[29]  S. Grossberg,et al.  Neural dynamics of form perception: boundary completion, illusory figures, and neon color spreading. , 1985 .

[30]  R. Gregory,et al.  Cognitive Contours , 1972, Nature.

[31]  F. Kingdom,et al.  A multi-channel approach to brightness coding , 1992, Vision Research.

[32]  S. Grossberg,et al.  Neural dynamics of form perception: boundary completion, illusory figures, and neon color spreading. , 1985, Psychological review.

[33]  R. Watt,et al.  A theory of the primitive spatial code in human vision , 1985, Vision Research.

[34]  S. Petry,et al.  Stimulus determinants of brightness and distinctness of subjective contours , 1983, Perception & psychophysics.

[35]  Stephen Grossberg,et al.  Neural dynamics of surface perception: Boundary webs, illuminants, and shape-from-shading , 1987, Comput. Vis. Graph. Image Process..

[36]  R. Day,et al.  The Relationship between Brightness Contrast and Illusory Contours , 1979, Perception.

[37]  Olaf Kübler,et al.  Simulation of neural contour mechanisms: from simple to end-stopped cells , 1992, Vision Research.

[38]  S. Zucker,et al.  Endstopping and curvature , 1989, Vision Research.

[39]  ANDREW SMITH,et al.  Tilt aftereffects with subjective contours , 1975, Nature.

[40]  D R Bradley,et al.  Organizational determinants of subjective contour: the subjective Necker cube. , 1977, The American journal of psychology.

[41]  R. von der Heydt,et al.  Mechanisms of contour perception in monkey visual cortex. I. Lines of pattern discontinuity , 1989, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[42]  D. Halpern,et al.  The Multiple Determination of Illusory Contours: 2. An Empirical Investigation , 1983, Perception.

[43]  Guy A. Orban,et al.  Illusory contour orientation discrimination , 1987, Vision Research.

[44]  A. T. Smith,et al.  Color-selective tilt aftereffects with subjective contours , 1976 .

[45]  D. Halpern,et al.  The Determinants of Illusory-Contour Perception , 1981, Perception.

[46]  Dennis M. Levi,et al.  The perceived strength of illusory contours , 1992, Perception & psychophysics.

[47]  J. Frisby,et al.  Illusory Contours: Curious Cases of Simultaneous Brightness Contrast? , 1975 .

[48]  I. Rock,et al.  Illusory Contours as the Solution to a Problem , 1979, Perception.

[49]  M. Grünau.  The involvement of illusory contours in stroboscopic motion , 1979 .

[50]  S Grossberg,et al.  Cortical dynamics of three-dimensional form, color, and brightness perception: II. Binocular theory , 1988, Perception & psychophysics.

[51]  Susan T. Dumais,et al.  The effects of illumination level and retinal size on the apparent strength of subjective contours , 1976 .

[52]  James Gordon,et al.  The existence of interpolated illusory contours depends on contrast and spatial separation , 1987 .

[53]  J. Kennedy,et al.  Line endings and subjective contours. , 1988, Spatial vision.

[54]  Ennio Mingolla,et al.  Neural Dynamics of Perceptual Grouping: Textures, Boundaries, And Emergent Segmentations , 1987 .

[55]  S. Coren,et al.  SUBJECTIVE CONTOURS AND APPARENT DEPTH , 2005 .

[56]  R. Day,et al.  A note on a second stage in the formation of illusory contours , 1980 .