Lecture 20 – Psyco 350, B1
Winter, 2011
N. R. Brown
Psyco 350 Lec #20 – Slide 1
Outline
Memory Illusions
• DRM False Memories
- The Paradigm
- Activation Monitoring Account
- An Alternative
• Recovered Memory Controversy
Psyco 350 Lec #20 – Slide 2
Memory Illusions
Phenomena:
• DRM-False Memories
• Misinformation Effect
• Implanted Memories
Theoretical Importance:
• highlights the complexity of memory for real-world
information.
• multiplicity of relevant memory processes: inference,
reconstruction, source/reality monitoring,
contextualized cued weighting
Psyco 350 Lec #20 – Slide 3
Deese/Roediger-McDermott (DRM)
False Memory Paradigm
•
•
(Nonpresented) Critical Lure (CL)
Converging Associates List
– most common word-association
responses
Psyco 350 Lec #20 – Slide 4
Deese/Roediger-McDermott (DRM)
False Memory Paradigm
•
•
(Nonpresented) Critical Lure (CL)
Converging Associates List
– most common word-association
responses
•
Tasks
– recognition
– recall
Psyco 350 Lec #20 – Slide 5
The Classic DRM Study
Roediger & McDermott, 1995
Method:
•
•
•
•
•
24 list
15 words/list
study time: 1.5 s/word
Post-list recall
Set-final recognition test: list-items, CL, unrelated.
Results:
• Recall: list (60%)  CL (57%)
• Recognition: list (78%)  CL (80%) >> unrelated (12%)
Psyco 350 Lec #20 – Slide 6
DRM -- Research
Background:
• The “Hot Topic” in memory
• Spawned from the Recovered Memory Controversy;
additional evidence for “productive” memory errors –
errors of commission.
Issues:
• What causes the FMs?
• How (and when) are CL correctly rejected?
Psyco 350 Lec #20 – Slide 7
Activation-Monitoring Theory
Roediger & Colleagues
In general: word processing causes activation to
spread related words in a semantic network
______________________________________
At study: activation spreads from list items to CL
At test: S encounters highly “primed” CL
Source Monitoring: Misattributes CL activation to
prior exposure
Psyco 350 Lec #20 – Slide 8
Support for A-M Theory
• False Memories (FMs) increase with degree of list
association.
(Deese, 1959; Roediger, et al. 2001)
• FM increase with number of associates on list.
(Robinson & Roediger, 1997)
Psyco 350 Lec #20 – Slide 9
Number of presented associates
(Robinson & Roediger, 1997, Exp 2)
24 list
15 words/list
study time: 2 s/word
associates presented
first, then fillers
----------------------------FMs  # associates
95
90
% of "Old" Responses
•
•
•
•
85
80
75
70
65
60
55
Present List Items
Nonpresented Critical Lures
50
45
3
6
9
12
# of Associates
on Study List
Psyco 350 Lec #20 – Slide 10
15
Support for A-M Theory
• False Memories (FMs) increase with degree of list
association.
(Deese, 1959; Roediger, et al. 2001)
• FM increase with number of associates on list.
(Robinson & Roediger, 1997)
• Blocked listed produce high rates of FMs than
randomized lists.
(McDermott, 1996)
Psyco 350 Lec #20 – Slide 11
Effect of Blocking on CLs
(McDermott, 1996, Exp 2)
Blocking  FMs
Blocking  Hits
60
55
% Recalled
• 3 DRM lists
• 15 words/list
• study time: 2 s/word
-----------------------------
Presented List Items
Nonpresented Critical Lures
50
45
40
35
30
25
Block
Random
Presenation Type
Psyco 350 Lec #20 – Slide 12
Problems w/ A-M Theory
Empirical Problems:
• A-M Theory incorrectly predicts factors that increase
hit rates will also increase FAs for CLs (see below).
Theoretical Problems:
• Time course at odds w/ semantic priming
• Monitoring assumes FM requires very frequent
errors of commission.
Implication: reality monitoring very unreliable.
Psyco 350 Lec #20 – Slide 13
An Alternative: List-Gist/Recollection Failure Approach
Two Main Assumptions:
1. Gist extracted during study & represented w/out
external detail.
2. Recollection failure (i.e. the absence of
recollective information in the presence of
high familiarity) is sometimes treated as a
memory cue.
Psyco 350 Lec #20 – Slide 14
An Alternative: List-Gist/Recollection Failure Approach
List-Gist Extraction:
• during study: effort-after-meaning  gist extraction
• gist represented in memory, without external detail
• gist reflects generalized meaning
• similarity between gist & CL meaning, a matter of
degree
Psyco 350 Lec #20 – Slide 15
List-Gist Extraction & FMs
Probability that gist will be extracted and/or that gist 
meaning of CL:
• # of related words (list length effect)
• degree of association
• proximity of related words (blocking)
Psyco 350 Lec #20 – Slide 16
An Alternative: List-Gist/Recollection Failure Approach
List-Gist
•
•
•
•
during study: effort-after-meaning  gist extraction
gist represented in memory, without external detail
gist reflects generalized meaning
similarity between gist & CL meaning, a matter of degree
Recollection Failure (Schacter; Brown, Buchanan, Cabeza)
when: (gist  CL meaning) + NO recollection:
– recollection common:
recollection failure  “New”
– recollection uncommon: recollection failure  “Old”
Psyco 350 Lec #20 – Slide 17
Recollection Failure
A Dual-Process– Weighted Cued Account
Familiarity
List Items
High
Critical Lures
Foils
• 1. low familiarity
• 2. recollection
• 3. high familiarity
+
recollection failure
Psyco 350 Lec #20 – Slide 18
Recollection
High
Low
 new
 old
? ?
yes
no
no
Dealing with Recollection Failure
• When recollectionlist is
very common, the
absence of recollection
indicates item is “New”
• When recollectionlist is
very rare, the absence of
recollection has no
bearing in recognition
decision (which will be
driven by familiarity)
Psyco 350 Lec #20 – Slide 19
Factor A:  P(recollectionlist)

 weight for recollection failure

 P(FAcritical items)
Psyco 350 Lec #20 – Slide 20
Recollection Failure & FMs
General prediction:
– Factors that increase recollection, decrease
FMs
Note: A-M position makes the opposite prediction.
Examples:
• study time
Psyco 350 Lec #20 – Slide 21
Effect of Study Time on CLs
(Gallo & Roediger, 2002, Exp 3)
Hits  w/ study time
70
% of "Old" Responses
• 16 DRM lists
• 15 words/list
----------------------------Study time Interaction:
FMs  w/ study time
65
60
55
50
45
Presented List Items
Nonpresented Critical Lures
40
1S
3S
Study Time
Psyco 350 Lec #20 – Slide 22
Recollection Failure & FMs
General prediction:
– Factors that increase recollection, decrease
FMs
Examples:
• study time
• presentation frequency
Psyco 350 Lec #20 – Slide 23
• 20 DRM lists
• 8 words/list
• study time: 4s/word
----------------------------Repetition Interaction:
FMs  w/ repetition
Hits  w/ repetition
% of "Old" Responses
Effect of Repetition on CLs
(Benjamin, 2001, Exp 1)
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
Presented List Items
Nonpresented Critical Lures
1
3
# of List Repetions
Psyco 350 Lec #20 – Slide 24
Recollection Failure & FMs
General prediction:
– Factors that increase recollection, decrease
FMs
Examples:
• study time
• presentation frequency
• presentation format (picture vs words)
Psyco 350 Lec #20 – Slide 25
•
•
•
•
14 DRM lists
12 words/list
study time: 1.5s/word
presentation: auditory w/
– printed word
– picture
----------------------------FMs  w/ picture
% of "Old" Response
Effect of Presentation Format on CLs
(Schacter, Israel, & Racine, Exp 2)
90
85
80
75
70
65
60
55
50
45
40
35
30
25
Presented List Items
Nonpresented Critical Lures
Word
Picuture
Presentation Mode
Psyco 350 Lec #20 – Slide 26
Summary
The Bottom Line:
•
•
Factors  gist = CL meaning,  FMs
Factors  list-item recollection,  FMs
Supports List-Gist Recollection Failure Account
Psyco 350 Lec #20 – Slide 27
Memory Illusions
Practical Importance:
• Clinical
• Forensic
Psyco 350 Lec #20 – Slide 28
The Recovered Memory Controversy
Psyco 350 Lec #20– Slide 29
The Recovered Memory Controversy
1. Background: The False Memory Hypothesis
2. Implanting False Memory
3. Forgetting CSA
4. The “Middle Ground” Position
Psyco 350 Lec #20– Slide 30
The Recovered Memory Controversy
Background:
• Adults report “recovering” forgotten memories of
childhood sexual abuse (CSA).
• Memories often recovered during therapy.
• Profound emotional & legal repercussions
Psyco 350 Lec #20– Slide 31
The Recovered Memory Controversy
Assumptions – The Recovered (“true”)
Memory Position:
• traumatic memories can be
repressed/suppressed
• recovery techniques produce valid memories of
real events.
• recovering forgotten CSA memories has
therapeutic value.
Psyco 350 Lec #20– Slide 32
Question Assumptions
• Do/can people repress/suppress memories of
CSA?
• Can recovery techniques produce false
memories?
• Does memory recovering CSA memories have
therapeutic value?
Psyco 350 Lec #20– Slide 33
Theoretical Response
Psyco 350 Lec #20– Slide 34
Lindsay & Read (1994)
Memory is fallible & subject to distortion.
Relevant Phenomena:
• Misinformation Effect – blend facts &
suggestion
• Source Amnesia – forget source of information
• Imperfect Reality Monitoring – mistaking
imagined events for real ones
• Reconstruction – past events reconstructed
from fragmentary details and schematic knowledge.
Psyco 350 Lec #20– Slide 35
Clinical Practice (circa, 1990)
When CSA suspected, recovery techniques
employed (over sessions)
Techniques:
• guided imagery
• hypnosis
• dream interpretation
• survivors’ groups
• uncritical acceptance of claims
Psyco 350 Lec #20– Slide 36
False Memories of CSA
“Memory recovery techniques may lead some
clients to create illusory memories.”
-- Lindsay & Read
Imagined and/or suggested events can take on
a realistic vividness and detail w/ extensive
memory work.
Psyco 350 Lec #20– Slide 37
The False-Memory Hypothesis
Psyco 350 Lec #20– Slide 38
False Memories of CSA
Step 1 – create CSA story
Step 2 – elaborate on CSA story
(suggestion, imagery, interpretation, hypnosis,
social facilitation)
Step 3 – forget or mistake origin of CSA story
(source amnesia, failed reality monitoring).
Implication:
• It should be possible to create FM in the lab.
Psyco 350 Lec #20– Slide 39
Implanting False Memories
Psyco 350 Lec #20– Slide 40
Implanting FMs /w Narrative Hyman et al. (1995)
Issue: Can FMs be implanted using clinical
techniques?
Method:
• Preparation: Solicit event descriptions from
parents
• Materials:
– 3 “real” event descriptions
– 1 “false” event description (spill punch bowl at
wedding)
Psyco 350 Lec #20– Slide 41
Hyman et al. (1995): Procedure
• Phase 1:
– Recall as much as possible about each event
& continue to reflect outside of lab.
• 2-day delay
• Phase 2 – repeat procedure
• Phase 3 – repeat procedure
Psyco 350 Lec #20– Slide 42
Hyman et al. (1995): Results
• true memories increase
across phases
• false memories increase
across phases
– Phase 2 FM = 25%
• Accessing background
knowledge predicts FM
– FMS for 11 or 30 Ss
who accessed BK
– FM for 2 of 20 Ss who
did not access
Psyco 350 Lec #20– Slide 43
Hyman et al (1995): Sample FM
Background
Knowledge
Psyco 350 Lec #20– Slide 44
Hyman et al (1995): Sample FM
Psyco 350 Lec #20– Slide 45
Hyman et al. (1995): Results
• Accessing background knowledge predicts FM
– FMs for 11 or 30 Ss who accessed BK
– FMs for 2 of 21 Ss who did not access BK
Interpretation:
suggestion + BK + source confusion FM
Psyco 350 Lec #20– Slide 46
Creating FMs w/ Photos:
Wade, Garry, Read, Lindsay (2002)
Method:
• 3 “real” childhood
photos
• 1 doctored childhood
photo
Task:
• recall as much as
possible
• three phases  1 week
apart
Psyco 350 Lec #20– Slide 47
Creating FMs w/ Photos:
Wade, Garry, Read, Lindsay (2002)
Results for False Photos:
• 1st Interview: 30% FMs
• 3nd interview: 50% FM
Conclusion:
Photos compiling for
support of generating
false event and accept
false memory.
Psyco 350 Lec #20– Slide 48
Implanted False Memories
Psyco 350 Lec #20– Slide 49
Three Stages Required to Implant FMs
Hyman & Loftus (1998)
1.
•
•
2.
Plausibility Assessment/acceptance
source (family, experts)
content (likelihood, consequentiality)
Memory Construction (creation of a plausible
imagined event)
• Actively relate proposed event to self-knowledge
• Imagery, journaling, dream interpretation
3. Source Monitoring Error.
• Situational/social demands
• Delay
• Repetition
Psyco 350 Lec #20– Slide 50
Implanting FMs
FM research:
• demonstrates FMs can be implanted
• refines techniques for creating FMs
Ethical Question:
• Is it time for a moratorium on this type of
work?
Psyco 350 Lec #20– Slide 51