Picture and Word False Memory in Autism Spectrum Disorder: A Developmental Perspective

Megan Borlase & Ewald Neumann

University of Canterbury

AUTISM SPECTRUM DISORDER (ASD)

LANGUAGE

BEHAVIOUR

SOCIAL

AUTISM

Intellectual

Memory

Perception

Executive functions

Central Coherence

Attention

Organization

Empathy

Theory of Mind

Co-ordination

Inhibitory Control

FALSE MEMORY“An apparent recollection of something that

one did not actually experience”E.g., Recovered Memories Can be believed with as much conviction

as a true memoryLaboratory tests:

StoriesShort films Association tasks (e.g. Deese, Roediger &

McDermott (DRM) paradigm)

DRM PARADIGM Developed by Deese (1959), Roediger and

McDermott (1995) Uses lists of words associated to an

unpresented ‘critical lure’ E.g., “sleep” = bed, rest, tired, dream,

slumber, snooze, snore… Found 55% of critical lures falsely recalled Can be used with pictures as well Reliably replicated in False Memory

studies

DRM STUDIES Age differences

False memory increases with age ASD studies

A lot of conflicting studies ASD adults have similar critical lure

recognition and higher studied item recognition than controls

ASD adults have lower critical lure and studied item recognition than controls

Confidence Ratings – ASD vs. controls ASD participants are more confident in their

true and false recognition than controls

EXPERIMENT ONE:-

INDIVIDUALS

HYPOTHESES1) False memories will increase

with age

2) ASD and control participants will have similar false recognition

PARTICIPANTS26 children, adolescents and

adults with ASD compared to 34 age matched controls

Recruited from Nelson, Christchurch, Wellington and Dunedin

WORD STIMULICRITICAL LURES

STUDIED WORDS

NOVEL WORDS(Recognition Task only)

E.g.,

Hammer

E.g.,

Nail, Builder, Saw, Wrench, Screwdriver, Axe, Tape measure, Screw

E.g.,

Throne, Queen

Crown, Castle

PICTURE STIMULICRITICAL LURES

STUDIED WORDS

NOVEL WORDS(recognition task only)

E.g., E.g., E.g.,

RECOGNITION TASK Contained 60 items

30 Studied Items (5 from each list)24 Novel ItemsThe 6 Critical Lures

Followed directly after each presentation Contained 4-point confidence rating:-

No/I don’t think so/I think so/Yes Read out by the researcher

“Did you hear/see…. (hammer)?” Participant paced

Age differences in false critical lure recognition for words and pictures averaged over ASD and control

participants (p<0.05)

0

10

20

30

40

50

60

70

80

90

Critical Lures Studied Items

% F

alse

cri

tical

lure

s re

cog

nis

ed

Children

Adolescents

Adults

Breakdown of age differences in false word critical lure recognition for ASD and controls (n.s.)

0

10

20

30

40

50

60

70

ASD Control

% F

alse

wor

d cr

itica

l lur

es

reco

gnis

ed

Children

Adolescents

Adults

ASD

0

10

20

30

40

50

60

70

80

Children Adolescents Adults

% o

f res

pons

es

Control

0

10

20

30

40

50

60

70

80

Children Adolescents Adults

% o

f res

pons

es

No

Don't think so

Think so

Yes

Differences in confidence ratings of word false critical lure recognition between ASD and control children, adolescents and adults (n.s.)

EXPERIMENT TWO:-

COLLABORATION

COLLABORATION Groups of three children or adolescents working

together to make decisions Clark et al. (2000) compared majority rule to

discussion based decision making in collaborative trios Trios had lower critical lure and higher studied

item recognition than individuals Discussion based decision making resulted in

higher studied item and lower critical lure recognition than majority rule

Age differences in collaboration False memory, in collaborative groups, increases with

age

HYPOTHESISCollaboration will be more

beneficial to ASD participants than controls

Benefits of collaboration will increase with age

METHOD 15 children and adolescents with ASD

compared to 15 age matched controls in collaborative trios

Used the same stimuli and recognition tasks as Experiment 1 except collaborative trios carried out the recognition tasks first individually and then as a collaborative group

Overall nominal vs. collaborative trio results for CL false recognition and

correct recognition of studied words

0

20

40

60

80

100

Critical Lures Studied Items

% a

ffirm

ativ

e re

spon

ses

Nominal

Collaborative

Age differences for false critical lure recognition in ASD and control

collaborative trios (p<0.05)

0

10

20

30

40

50

60

ASD Control

% f

als

e r

eco

gn

itio

n

Children

Adolescents

Children

-15

-10

-5

0

5

10

15

20

25

Critical Lure Studied Item

Impr

ovem

ent f

rom

wor

king

col

labo

rativ

ely

Improvement in the correct rejection of CLs and recognition of studied words as a result of working collaboratively for ASD and control groups

Adolescents

0

5

10

15

20

25

Critical Lure Studied Item

Impr

ovem

ent f

rom

wor

king

col

labo

rativ

ely

ASD

Control

p<0.05 p<0.05

n.s.

n.s.

SUMMARY ASD participants had similar SI and higher false

CL recognition than controls possibly due to impaired inhibitory control.

SI recognition increased with age as did CL recognition in both individuals and collaborative trios.

Adults had lower CL recognition than younger groups possibly due to the use of categorical lists.

ASD participants generally had higher confidence in their false memories than controls

Collaboration was detrimental to ASD children but beneficial to all other groups most likely resulting from the decision making techniques applied

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Increased discrimination of “false memories” in autism spectrum disorder. PNAS, 97(15), 8734 – 8737.

Bowler, D.M., Gardiner, J.M., Grice, S. & Saavalainen, P. (2000). Memory illusion: false recall and recognition in adults with asperger’s syndrome. Journal of Abnormal Psychology, 19(4), 663 – 672.

Carlin, M.T., Toglia, M.P., Wakeford, Y., Jakway, A., Sullivan, K. & Hasel, L. (2008). Verdical and false pictorial memory in individuals with and without mental retardation. American Journal on Mental Retardation,113(3), 201 – 213.

Christ, S.E., Holt, D.D., White, D.A. & Green, L. (2007). Inhibitory control in children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 37, 1155 – 1165.

Clark, S.E., Hori, A., Putnam, A. & Martin, T.P. (2000). Group collaboration in recognition memory. Journal of Experimental Psychology, 26(6), 1578 – 1588.

Deese, J. (1959). On the prediction of occurrence of particular verbal intrusions in immediate recall. Journal of Experimental Psychology, 58(1), 17 – 22.Roediger & McDermott

Howe, M.L., Wimmer, M.C. & Blease, K. (2009). The role of associative strength in children’s false memory illusions. Memory, 17(1), 8 – 16.

Loftus, E. (2003). Our changeable memories: legal and practical implications. Nature Review Neuroscience, 4, 231 – 234.

Loftus, E.F. (1997). Creating false memories. Scientific American, 71 – 75. Warne, J. (2010, April). The Asperger’s Epidemic. North & South, p. 38.