How perceived causality influences perceived symmetry Patrick Spröte, Filipp Schmidt & Roland W. Fleming Department of Psychology, Justus-Liebig-University Giessen, Germany
gh
ten
Apple
Ellipse
Bitten ellipse
VSS 15 annual meeting
fit to responses (non-linear PCA)
Butterfly
Heart
Kidney
Rectangle
complete
sm oo
the d
bit ten
et e pl co m shape 1
complete
bitten
smoothed
superimposed smoothed bitten conditions
gh rou neither (smooth)
Banana
shape 10
shape 2
shape 10
partly rough
rough
1,2 & 3
1,3,4 & 5
complete bitten
partly rough rough
complete bitten smoothed partly rough rough
• Subjects spontaneously compensate for ‘bites’ in symmetric & familiar shapes
Conclusion
Experiment 1
Shape A
shape skeletons (grassfire)
shape 5 shape 4
shape 7
ten
bit
Subjects take ‘bites’ into account!
‘true’ axes
shape 6
shape 6
smoothed
neither (’smooth’)
fit to shape contour (non-linear PCA)
shape 7
shape 3
Roughness does not determine ‘bite’ interpretation gh
rou
ten
rou
complete bitten smoothed
rou
gh
Task
bit neither (’smooth’)
shape 10
shape 5
bit
Experiment 3
gh
ten
rou
bit neither (’smooth’)
shape 11
shape 8
neither (smooth)
2. Dot placement
Bitten shape similarity complete compared to smoothed shape 9
How does causal interpretation of negative parts influence perceived symmetry?
1. Rating
shape 2
shape area
shape scission transformation
Transformation
perceived symmetry axis
‘true’ shape
ten
Experiment 2
Similar concavities Different causes
Interpretation changes perceptual organization bit
Introduction
Examples where the process shaping the object is salient
• For asymmetric & unfamiliar shapes subjects are uncertain about response • Reported symmetry axis changes with causal interpretation of concavity • Generative models of shape play an important role in perceptual organization and shape perception
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‘true’ shape
intrinsic properties stable, intrinsic attributes of objects: e.g. material
extrinsic properties variable, incidental attributes of scene or viewing circumstances: e.g. processes/forces
shape scission transformation
CIOTAS Corp. 2015
