Change Blindness Meredith Curtis Laurel Calderwood Undergraduate Research Symposium August 11, 2006.
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Change Blindness Meredith Curtis Laurel Calderwood Undergraduate Research Symposium August 11, 2006
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Transcript of Change Blindness Meredith Curtis Laurel Calderwood Undergraduate Research Symposium August 11, 2006.
Change Blindness
Meredith CurtisLaurel Calderwood
Undergraduate Research SymposiumAugust 11, 2006
Overview
• Visual Short-Term Memory
• Eye Tracking
• Change Detection Strategies
• Experiment 1: Change Blindness
• Experiment 2: Cued Change Blindness
• Conclusions
Visual Short-Term Memory
• VSTM
• What is change blindness?
A
A’
A
A’
Visual Short-Term Memory
• VSTM
• What is change blindness?
• How is it caused?
• Reveals that we usually overestimate the capacity of VSTM– We think we remember…but we don’t
Procedure
• Track participant using video-based eye tracker
• Data then coded– Fixations-at least 100 milliseconds
• Results interpreted from text file– What are we looking for?
Video-Based Eye Tracker
• How does it work?– Remote– Captures image of the eye– Tracks pupil/first surface reflection
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Video-based Eye Trackers
Flicker Paradigm• A, B, A’, B
– A: 1 second– B: 20 milliseconds
• Types of Changes– Position– Addition/Subtraction– Color/Illumination
A
B
A’
B
Example Movie
Question
• How do people move their eyes about an image while searching for a change?
??
Two Hypotheses
• Hypothesis #1– Fixations made
randomly until change is found
Two Hypotheses
• Hypothesis #2– Fixations gradually
move towards change: “preconscious” detection
Experiment 1• Change Blindness
• 15 RIT Students– 9 Males– 6 Females
• 20-26 Years old
Hypothesis #1:No Pattern
Distance to Center of Change
0
50
100
150
200
250
300
350
400
450
500
5 15 25 35 45 55 65 75 85 95Fixation #
Dis
tance
fro
m C
hange (
Pix
els
)
y
Distance to Center of Change
0
50
100
150
200
250
300
350
400
450
5 15 25 35 45 55 65 75 85 95
Fixation #
Dis
tance
fro
m C
hange (
Pix
els
)
y
What We Are Looking ForHypothesis #2:Decrease Towards Zero
Distance to Target Center
0.00
100.00
200.00
300.00
400.00
500.00
600.00
0 2 4 6 8 10 12 14 16 18
Fixation #
Dis
tan
ce
fro
m t
arg
et
(pix
els
)
female age 20
male age 21
male age 20
female age 21
Tracking eyes
57
107
157
207
257
307
357
59 259 459
X coordinate
Y c
oord
inate
female age 20fixations
Change blindnesscoordinatesfemale age 20starting point
male age 21fixations
male age 21starting pointmale age 20fixations
male age 20starting point
female age 21fixationsfemale age 21starting point
Y c
oo
rdin
ate
Distance to Target Center
Auburn Air Patrol
Distance to Target Center: Subject 1
0.00
50.00
100.00
150.00
200.00
250.00
300.00
350.00
400.00
450.00
500.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Fixation #
Dis
tanc
e (P
ixel
s)
Distance to Target Center: Subject 2
0.00
100.00
200.00
300.00
400.00
500.00
600.00
1 2 3 4 5 6 7 8 9 10
Fixation #
Dis
tanc
e (P
ixel
s)
Distance to Target Center: Subject 3
0.00
100.00
200.00
300.00
400.00
500.00
600.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Fixation #
Dis
tanc
e (P
ixel
s)
Distance to Target Center: Subject 4
0.00
100.00
200.00
300.00
400.00
500.00
600.00
1 2 3 4 5 6 7
Fixation #
Dis
tanc
e (P
ixel
s)
Distance to Target Center: Subject 1 Distance to Target Center: Subject 2
Distance to Target Center: Subject 3 Distance to Target Center: Subject 4
Tracking eyes
68
118
168
218
268
318
368
58 158 258 358 458 558
X coordinate
Y c
oo
rdin
ate
female age 20fixations
Change blindnesscoordinates
female age 20starting point
male age 21fixations
male age 21starting point
male age 20fixations
male age 20starting point
female age 21fixations
female age 21starting point
Shadows
Distance to Target Center: Subject 1
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
1 2 3 4 5 6 7 8
Distance to Target Center: Subject 2 (failed)
0.00
50.00
100.00
150.00
200.00
250.00
300.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Distance to Target Center: Subject 3
0.00
50.00
100.00
150.00
200.00
250.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Distance to Target Center: Subject 4 (failed)
0.00
50.00
100.00
150.00
200.00
250.00
300.00
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35
Distance to Target Center: Subject 1 Distance to Target Center: Subject 2 (failed)
Distance to Target Center: Subject 3 Distance to Target Center: Subject 4 (failed)
Preconscious?
Distance to Target Center: Subject 3
0.00
100.00
200.00
300.00
400.00
500.00
600.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Fixation #
Dis
tanc
e (P
ixel
s)
Distance to Target Center: Subject 4
0.00
50.00
100.00
150.00
200.00
250.00
300.00
350.00
400.00
1 2 3 4 5
Distance to Target Center: Subject 1
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
1 2 3 4 5 6 7 8
Random?
Distance to Target Center: Subject 3
0.00
50.00
100.00
150.00
200.00
250.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Distance to Target Center: Subject 3
0.00
50.00
100.00
150.00
200.00
250.00
300.00
350.00
400.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Distance to Target Center: Subject 4
0.00
50.00
100.00
150.00
200.00
250.00
300.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Data analysis is ongoing …
Where we are now
Experiment 2:Cued Change Blindness
Thermal infrared (IR) systems are used in search
and rescue, law enforcement, and by the military.
ApplicationApplication
www.geocities.com
www.infraredsystems.com
www.ecologicalbuildingsystems.com
• Augmented search
• First, do no harm.
What is different?
• Similar Procedure
• Addition of ‘cues’ in each image set
• Valid or Invalid Cues
Hypotheses
• Valid - Eyes drawn to target, decreased detection latency
• Invalid - Distract eyes from target, increased detection latency
Invalid Cue
Valid Cue
Acknowledgements
• Dr. Jeff Pelz
• Dr. Andrew Herbert
• Everyone in the Visual Perception Lab
• COS Summer Research
