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Power Point presentation used in 2012 at Penn State Behrend\'s Sigma Xi Undergraduate Research Conference.
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How Do We Recognize Faces?
Penn State Behrend
Kristan Russell Erin McCreary|
Our Study
• Eyewitness Identifications• Lateralization Priming• The Study• Results
VariablesEstimator Variable System
Variable Can not be controlled. Can and should
be controlled.
Estimator Variables
History
• Witnessed violence
• Experienced violence
• Has viewed a photo array or line-up
Demographics
• Age• Race• Gender
• Of both the witness and perpetrator
Situation
• Presence of a weapon
• Trauma• Stress
Confidence
• Confidence level the witness has in making an identification
System Variables
Procedure
• Photo array• Line up
• Sequential• Simultaneous
Foils
• Similarity• Quantity
Process
• Administration• Instructions• Instructor
Lateralization
• Global• Local• Priming
possibilities
• More recent
LateralizationGlobal
Associated with the right hemisphereMay enhance recognition accuracy
LocalAssociated with the left hemisphereMay reduce recognition accuracy
global
local
Priming the Brain
GlobalIdentifying the larger letter“A”
LocalIdentifying the smaller letters“S”
Navon Letters
Macrae & Lewis, 2002
Priming the BrainGlobal
Identifying the direction the large square opens toward“right”
LocalIdentifying the direction the small squares open towards“left”
Hierarchical Figures
Hypotheses
I. Global Lateralization tasks will enhance facial recognition accuracy.
II. Local Lateralization tasks will impair facial recognition accuracy.
I. (Macrae & Lewis, 2002)III. Overall confidence will
significantly influence facial recognition accuracy.
Method
• IRB – Research Approved
• Participants:• Penn State Behrend• 18-24 years (M = 19)• 65 total
• 49 female - 16 male• 85% Caucasian
Method• Stimuli:
• Informed Consent• Demographic Survey• Priming Tasks
• Control• Navon Letters Global• Navon Letters Local• Hierarchical Figures Global• Hierarchical Figures Local
The Procedure
Informed Consent
Demographic Survey
The Procedure Shown 10 Photos
The ProcedureRandomly Assigned Task
You will now be shown a large square made up of smaller squares. As the image appears please identify which
direction the LARGE square is open towards.
Answers can be:
Up Down Left Right
The ProcedureRandomly Assigned Task
Up Down Left Right
The ProcedureRandomly Assigned Task
Up Down Left Right
The ProcedureRandomly Assigned Task
Up Down Left Right
The ProcedureRandomly Assigned Task
Up Down Left Right
The Procedure
Was this photo in the original photo array you viewed?
YES NO
The Procedure
How confident are you about your decision?
1 2 3 4 5 6 7
Not at all UnsureExtremely
ConfidentConfident
The Procedure
Was this photo in the original photo array you viewed?
YES NO
The Procedure
How confident are you about your decision?
1 2 3 4 5 6 7
Not at all UnsureExtremely
ConfidentConfident
The Procedure
Debriefed
Given Credit for Participation
Results
Faci
al
Reco
gn
itio
n
Acc
ura
cy (
%)
Task Type and Priming Condition
Navon Letters Hierarchical Figures50
55
60
65
70
75
80
Global
Control
Local
Results
I. No significant effect of gender
II.Global Priming Groups were not significantly more accurate
III.No significant relationship between accuracy and confidence
Navon Letters Hierarchical Figures
50
60
70
80
GlobalControlLocal
Results
I. Main effect of “Priming Group” on Accuracy.I. ANOVA Results
I. F(2,59) = 6.45, p =.003
II. Local Priming Groups for both tasks displayed less accurate compared to the control and global groups. I. Post Hoc T-Test Results:
I. t(59) = 3.20, p = .002 [global vs local]II. t(59) = 3.24, p = .002 [control vs
local]
Navon Letters Hierarchical Figures
50
60
70
80
GlobalControlLocal
Implications• Understand the factors that influence
facial recognition accuracy– Use to our advantage
• Take our knowledge into account when – Confidence– Jurors
• Strong Emphasis False Convictions
Future Research• Target population:
• Broaden
• Incorporating other variables• How they interact
• Female perpetrators/foils• Only white males were used
Acknowledgments
This research was made possible through an Undergraduate Student Research Grant at Penn State Erie, The Behrend College. Special thanks to our research advisor Dr. Dawn Blasko.
References• Hills, P., & Lewis, M. (2009). A spatial frequency account of the
detriment that local processing of navon letters has on face recognition. Journal of Experimental Psychology, 35(5), 1427-1442.
• Lawson, R. (2007). Local and global processing biases fail to influence face, object, and word recognition. Visual Cognition, 15(6), 710-740.
• Macrae, C., & Lewis, H. (2002). Do i know you? processing orientation and face recognition. Psychological Science, 13(2), 194-196.
• Perfect, T., Dennis, I., & Snell, A. (2007). The effects of local and global processing orientation on eyewitness identification performance. Memory, 15(7), 784-798