eyewitnesses with mild learning disabilities: face recognition and description abilities presenter:...
TRANSCRIPT
Eyewitnesses with mild learning disabilities:
Face recognition and description abilities
Presenter:Julie Gawrylowicz
Supervisory team:Dr Derek Carson, Dr Fiona Gabbert, University of Abertay Dundee,
Professor William Lindsay, University of Abertay Dundee and NHS Tayside andProfessor Peter Hancock, University of Stirling
UNIVERSITY OF ABERTAY
Definition: Learning disability (LD)
Hard to define! Too many definitions depending on… Century Country Domain 4 sub-categories
Criteria utilized during current experiment to define mild learning disability (mLD) (WHO, 1992) Significant impairment of intellectual functioning (IQ 50-70) Significant impairment of adaptive/social functioning Age of onset before adulthood
Relevance
LD might have serious impacts on reliability and accuracy of an eyewitness account, since it influences several cognitive skills
High prevalence rate (Emerson, 2001)
People with LD are more susceptible to victimization (Memon & Bull, 1999)
Limited research
Theoretical background – What do we know so far?
Eyewitness research with people with LD:
Suggestibility and acquiescence Open- vs. closed-ended questions The Cognitive Interview (CI)
Research Questions
Do participants with mLD perform differently than controls? During a facial recognition task During a facial description task
Present Study
Participants 30 with mLD (21-58; mean = 39 yrs;
WASI: FSIQ-4 score: mean = 58.48, SD = 5.28, range = 52 - 70) 30 controls (19-54; mean = 29 yrs)
Two parts Recognition task Description task
Face-recognition task
Design Between-subjects design DV: Accuracy of recognition (old/new judgments)
Procedure Study phase Test phase
2 practice trials
Face-recognition task: Practice trial І
Study phase face on screen for
10s
Test phase
2 faces(1 old; 1 new)
presented in random and sequential order
for each participants gave old/new judgements
each on screen for as long as participant needed to make decision
10s
Study phase Test phase
Face-recognition task: Practice trial ІІ
Study phase
10s
10s
Test phase Study phase
3 Mr Men on screen for 10s
presented in random and sequential order
Test phase 6 faces (3 old; 3 new)
presented in random and sequential order
for each participants gave old/new judgements
each on screen for as long as participant needed to make decision
10s
Face-recognition task: main task
Study phase Test phase
Study phase 5 faces on screen for
10s
presented in random and sequential order
Test phase 10 faces (5 old; 5 new)
presented in random and sequential order
for each participants gave old/new judgements
each on screen for as long as participant needed to make decision
10s
10s
10s
10s
10s
Face-recognition task: Results
main effect for group (p<.05)
Face-description task
Design Mixed design DV: Amount and accuracy of facial information reported.
Procedure Describe from memory: the face disappeared after 10s
Free recall Cued recall
Describe from photo: the face was visible all the time Free recall Cued recall
Question format
Free recall “What did the face look like you have just seen on my computer?
Tell me as much about it as you can.” “Can you tell me something else about the face?”
Cued recall “What did the hair look like of the face you have just seen on my
computer?” “What did the eyebrows look like of the face you have just seen
on my computer?”
Face-description task: Stimuli
Face-description task: Results Ι - Quantity
main effect for group (p<.05)
main effect for recall (p<.05)
interaction between recall and group (p<.05)
main effect for group (p<.05)
main effect for recall (p<.05)
Face-description task: Results ΙΙ - Accuracy
main effect for group (p<.05) main effect for group (p<.05)
Interaction between recall and group (p<.05)
Conclusions
participants with mLD performed poorer on both face recognition and face description tasks than controls
participants with mLD and controls mentioned more facial details during the cued recall than during the free recall
trends indicate that, in contrast to controls, participants with mLD mentioned more appropriate details during the cued recall than during the free recall
Possible future directions
Do visual prompts help people with mLD to give more accurate and detailed facial descriptions? Example of visual prompts:
Thank you for listening!