proportion correct answers
DESCRIPTION
"To bite, or not to bite“: Perceived causality in the perception of negative parts. β. α. Patrick Spröte & Roland W. Fleming | Justus-Liebig Universität Gießen. The larger the missing portion, the more ‘bitten‘. The more concave, the more ‘bitten‘. Background. - PowerPoint PPT PresentationTRANSCRIPT
Pro
porti
on c
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ct a
nsw
ers
Subject IDS1 S2 S3 S4 S5 S6 S7 S8 S9 S10
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Proportion correct answers across subjects
"To bite, or not to bite“: Perceived causality in the perception of negative partsPatrick Spröte & Roland W. Fleming | Justus-Liebig Universität Gießen
BackgroundOur data suggest that subjects are good at inferring the causal history of unfamiliar ‘bitten’ 2D shapes.On a between subject basis the relative depth of a negative part & and its relative area are good predictor of the subjects’ judgements.
Subjects can do the task Subjects are confident Differences in judgements
The more concave, the more ‘bitten‘
The larger the missing portion, the more ‘bitten‘
The more angles, the more ‘bitten‘
60° 90° 108° 135° 152° -5.31 -3.67 -2.51 -0.95 0.72
Decomposition Negative Parts
Stimuli were created from convex, irregular hexagons. From half of the stimuli, a portion of the shape was deleted by random intersection with another hexagon and removing the region of overlap.
Whole
Bitten
Stimulus statisticsα β
Relative area Mean of interior angles
Width of aperture
Relative depth
We presented different shapes in different sizes and orientations. Subjects indicated with a cursor on a 10-point scale the extent to which each object appeared to them to be ‘bitten‘.
Time
Interior angles are no longerpredictive
Relation to figure/ground
The investigated shape properties in Experiment 1 were highly inter-correlated. Therefore we conducted a second Experiment with a set of stimuli for which, by design, the correlation between “mean of interior angles” & “relative depth” was kept near zero.
Relatability
Stimuli: “Hexagon world”
Task
Results (Experiment 1)
Results (Experiment 2)
Discussion
Genericity
Decreasing Symmetry
counting vertices
concave = bitten
mean
Rel
ativ
e fre
quen
cy
Ratingbittenwhole
Relative frequency categories were used
1 2 3 4 5 6 7 8 9 100
0.02
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0.12
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Pro
porti
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ct a
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(who
le s
hape
s)Proportion correct answers
(bitten shapes)
Interindividual differences injudging ‘bitten‘ vs. ‘whole‘ shapes
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Mean of the interior angles55 65 75 85 95 105 115 125 135 145 155
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Rat
ing
bitte
nw
hole
Average rating as a function of the mean of the interior angles
log relative depth-6 -5 -4 -3 -2 -1 0 1
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Rat
ing
bitte
nw
hole
Average rating as a function of the logarithm of relative
depth
-6 -5 -4 -3 -2 -1 01
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log relative area
Rat
ing
bitte
nw
hole
Average rating as a function of the logarithm of relative
areaR²=.63
R²=.76
R²=.90
55 65 75 85 95 105 115 125 135 145 1551
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Mean of the interior angles
Rat
ing
bitte
nw
hole
Average rating as a function of the mean of the interior angles
-6 -5 -4 -3 -2 -1 01
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3
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5
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9
10
Average rating as a function of the logarithm of relative depth
log relative depth
Rat
ing
bitte
nw
hole
Negative parts‘ concavity predicts ‘bites‘
R²=.10
R²=.59
-9 -8 -7 -6 -5 -4 -3 -2 -1 01
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Average rating as a function of the logarithm of relative area
R²=.33
log relative area
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1R² (mean interior angles) as a
function of R² (log relative depth)
R² (log relative depth)
R² (
mea
n of
the
inte
rior a
ngle
s)
Mean of interior angles loses predictive power when
uncorrelated with relative depth
90° 108° 120° 135° 140°129° -5.22 -3.88 -0.42-1.77-2.6 -8.76 -5.75 -3.4 -1.2 -0.64
-5.6 -3.74 -2.73 -1.64 -0.54