A new visual phenomenon, inter-attribute illusory (completed) contours, is demonstrated. Contour completions are perceived between any combination of spatially separate pairs of inducing elements (Kanizsa-like ‘pacman’ figures) defined either by pictorial cues (luminance contrast or offset gratings), temporal contrast (motion, second-order-motion or ‘phantom’ contours), or binocular-disparity contrast. In a first experiment, observers reported the perceived occurrence of contour completion for all pair combinations of inducing elements. In a second experiment they rated the perceived clarity of the completed contours. Both methods generated similar results—contour completions were perceived even though the inducing elements were defined by different attributes. Ratings of inter-attribute clarity were no lower than in either of the two corresponding intra-attribute conditions and seem to be the average of these two ratings. The results provide evidence for the existence of attribute-invariant Gestalt processes, and on a mechanistic level indicate that the completion process operates on attribute-invariant contour detectors.
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References
1.
BerkleyM ADeBruynBOrbanG, 1994“Illusory motion and luminance defined contours interact in the human visual system”Vision Research34209–216
DavisGDriverJ, 1994“Parallel detection of Kanizsa subjective figures in the human visual system”Nature371791–793
4.
DrespBBonnetC, 1993“Psychophysical measures of illusory form perception: further evidence for local mechanisms”Vision Research33759–766
5.
DrespBGrossbergS, 1997“Contour integration across polarities and spatial gaps: From local contrast filtering to global grouping”Vision Research37913–924
6.
DrespBSalvano-PardieuVBonnetC, 1996“Illusory form with inducers of opposite contrast polarity: evidence for multistage integration”Perception & Psychophysics58111–124
7.
DumaisS TBradleyD R, 1976“The effects of illumination level and retinal size on the apparent strength of subjective contours”Perception & Psychophysics19339–345
8.
FieldD JHayesAHessR F, 1993“Contour integration by the human visual system: Evidence for a local association field”Vision Research33173–193
9.
FinkelL HEdelmanG M, 1989“Integration of distributed cortical systems by reentry: A computer simulation of interactive functionally segregated visual areas”Journal of Neuroscience93188–3208
GrosofD HShapleyR MHawkenM J, 1993“Macaque V1 neurons signal ‘illusory’ contours”Nature365550–552
12.
GrossbergSMingollaE, 1985“Neural dynamics of form perception: Boundary completion, illusory figures, and neon color spreading”Psychological Review92173–211
13.
HeitgerFvon der HeydtR, 1993“A computational model of neural contour processing: Figure – ground segregation and illusory contours”, in 4th IEEE International Conference on Computer Vision (Los Alamitos, CA: IEEE Computer Society Press) pp 32–40
14.
von der HeydtRPeterhansEBaumgartnerG, 1984“Illusory contours and cortical neuron responses”Science2241260–1262
15.
von der HeydtRZhouHFriedmanH S, 2000“Representation of stereoscopic edges in monkey visual cortex”Vision Research401955–1967
16.
HubelD HWieselT N, 1965“Receptive fields of single neurons in two nonstriate visual areas 18 and 19 of the cat”Journal of Physiology28229–289
17.
JuleszBFrisbyJ P, 1975“Some new subjective contours in random-line stereograms”Perception4145–150
18.
KanizsaG, 1955“Margini quasi-percettivi in campi con stimolazione omogenea”Rivista di Psicologia497–30 [translated in The Perception of Illusory Contours Eds PetrySMeyerG E (1987, New York: Springer) pp 40–49]
LammeV A Fvan DijkB WSpekreijseH, 1993“Contour from motion processing occurs in primary visual cortex”Nature363541–543
22.
LesherG W, 1995“Illusory contours—toward a neurally based perceptual theory”Psychonomic Bulletin & Review2279–321
23.
LesherG WMingollaE, 1993“The role of edges and line-ends in illusory contour formation”Vision Research332253–2270
24.
LiZ, 1998“A neural model of contour integration in the primary visual cortex”Neural Computation10903–940
25.
MarcarV LRaiguelS EXiaoDMaesHOrbanG A, 1992“Do cells in area V2 respond to the orientation of kinetic boundaries?”Society for Neuroscience Abstracts181275
26.
MareschalIBakerC L, 1998“A cortical locus for the processing of contrast-defined contours”Nature Neuroscience1150–154
27.
MatthewsNWelchL, 1997“The effect of inducer polarity and contrast on perception of illusory figures”Perception261431–1443
28.
PeterhansEvon der HeydtRBaumgartnerG, 1986“Neural responses to illusory contours reveal stages of visual cortical processing”, in Visual Neuroscience Ed. PettigrewJ DSandersonK JLevickW R (Cambridge: Cambridge University Press) pp 343–351
29.
PetrySHarbeckAConwayJLeveyJ, 1983“Stimulus determinants of brightness and distinctness of subjective contours”Perception & Psychophysics34169–174
30.
PoomL, 2000“Inter-attribute tilt effects and orientation analysis in the visual brain”Vision Research402711–2722
31.
PrazdnyK, 1983“Illusory contours are not caused by simultaneous brightness contrasts”Perception & Psychophysics34403–404
32.
PrazdnyK, 1986“Illusory contours from inducers defined solely by spatiotemporal correlation”Perception & Psychophysics39175–178
33.
RamachandranV SRaoV MVidyasagarT R, 1973“Apparent movement with subjective contours”Vision Research131399–1401
34.
RivestJCavanaghP, 1996“Localization of contours defined by more than one attribute”Vision Research3653–66
35.
RockIAnsonR, 1979“Illusory contours as a solution to a problem”Perception8665–681
36.
RogersB JRamachandranD CRamachandranV S, 1991“Phantom contours: selective stimulation of the magnocellular pathways in man”Investigative Ophthalmology & Visual Science26(4) 1034
37.
SchumannF, 1900“Beiträge zur Analyse Gesichtswahrnehmungen: Erste Abhandlung einige Beobachtungen über die Zusammenfassung von Gesichteindrücken zu Einheiten”Zeitschrift für Psychologie und Physiologie der Sinnesorgane231–32 [translated in The Perception of Illusory Contours Eds PetrySMeyerG E (1987, New York: Springer) pp 21–34]
38.
ShapleyRGordonJ, 1986“Neural mechanisms of subjective contours”Perception & Psychophysics39214–215
39.
ShipleyTKellmanP J, 1992“Strength of visual interpolation depends on the ratio of physically specified to total edge length”Perception & Psychophysics5297–106
40.
TylerC W, 1975“Stereoscopic tilt and size aftereffects”Perception4187–192
41.
VictorJ DConteM M, 1998“Quantitative study of effects of inducer asynchrony on illusory contour strength”Investigative Ophthalmology & Visual Science39S206
42.
WatanabeTOyamaT, 1988“Are illusory contours a cause or a consequence of apparent differences in brightness and depth in the Kanizsa square?”Perception17513–521
43.
WenderothPJohnstoneS, 1987“Possible neural substrates for orientation and perception”Perception16693–709
44.
WenderothPJohnstoneS, 1988“The different mechanisms of the direct and indirect tilt illusions”Vision Research28301–312
45.
WertheimerM, 1923“Untersuchungen zur Lehre von der Gestalt”, in A Source Book of Gestalt Psychology Ed. EllisW D (London: Routledge and Kegan Paul) pp 71–88
46.
van der ZwanRWenderothP, 1995“Mechanisms of purely subjective contour tilt aftereffects”Vision Research352547–2557
