False memories Flashcards
What is the Deese-Roediger-McDermott memory illusion?
Task based on word lists:
Strong* tendency to falsely recognise or recall a critical lure as having been presented.
Roediger and McDermott (1995, based on Deese, 1959)
Why do we get false memories? Schacter et al. (2011)
Gist activation = study phase
Errors derive from knowledge base: associations between studied words and the ‘critical lure’, as in ‘free association’ tasks
Idea that memory encompasses semantically related unstudied
content = gist memory
Memory is general as well as specific +
What is the DRM memory illusion?
Memories for lures = vivid + frequent as memory for the studied items!
- Hippocampal damage reduces this type of false memory = normal function
Medial prefrontal damage also reduces it = consistent w/ semantic knowledge schemas’ role in errors
Dorsolateral prefrontal cortex damage + old age increase the illusion – implies memory control is involved
What is gist memory for pictures?
Categorised pictures ~20% false alarms on recognition test
Also called mnemonic discrimination + impaired in ageing +
Alzheimer’s
Study phase
Test phase = what is new + what is old
Lures = study was sleep
Koutstaal & Schacter (1997); Yassa and Stark (2011)
What is a critical lure?
A related word to the memory
What happened in Brewer and Tureen (1981)
Looked at memory for object rated by schema office
Objects rate by schema-expectancy
Schema-exectancy helped recall of objects
More false recognition of high-schema objects in recognition memory test = can be based on semantic gist +shared w/ real events
How are real memories the same as false memories?
Garoff-Eaton, Slotnick & Schacter, 2006
Participants scanned during recognition test
View abstract shapes – distinguish lures from studied
fMRI activity at retrieval indistinguishable for true vs. false
recognition = null finding, so cannot confirm it
ALSO abstract = minimal semantic processing so no semantic gist
How are real memories different as false memories?
Dennis, Bowman & Vandekar (2012)
fMRI memory retrieval study = focus on subjectively vivid true vs. false recollections
Stimuli were everyday objects that could elicit a memory based on semantic gist – e.g. “yes I saw a cat”
Right hippocampus + early visual cortex = more activated during true recollection vs false recollection
Evidence that true recollection = different = perhaps more
detailed, and containing more sensory information?
What does meta-analysis show about the difference/ similarities of real and false memories? (Kurkela and Dennis, 2016)
Several PFC regions commonly activated over studies = more for false memories than real = Interpret as greater memory monitoring demands (trying to analyse is this is real)
- Included: bilateral ventrolateral PFC – semantic gist?
- BUT not all activations differed from true recognition
- AND no consistent differences = hippocampus/ sensory cortex
How does false memories link to reinstatement?
Sometimes true memories engage hippocampus more and
sometimes sensory cortex more, perhaps reflecting
reinstatement of more details of original events
No studies have experimentally manipulated the
information that is recollected to check these interpretations
More studies need to separate properly episodic recollection
from familiarity to see if true/false recollections really differ
what is Bartlett’s (1932) War of the Ghosts?
People recalled unfamiliar stories – shorter and distorted – elements changed as well as omitted
Memory distortion when to-be-remembered info =
does not fit our schemas
Memory tested after 15m + randomly on campus after weeks, months or years
What study looked at students’ event memory?
Wynn & Logie (1998) tested students’ memories for their first
week at university every few weeks
Accurate & stable over ~ 1 year despite initial memory test
* AND: accuracy verified by lecturers/ porters notes at time
* BUT: the initial memory test was not for 2-3 weeks
Memory distortion = less common in ‘naturalistic conditions’
Consistent w/ proposed role of schemas = memories fit a schema well
What are the criticisms of Bartlett’s methods?
Not well controlled
* E.g. deliberate guessing
* NO statistics!
What does Graesser et al. (1980) show?
Shows evidence for distortion at longer study-test delays
Measured distortion of text recall bc of prior knowledge as correlation between:
* Chance of recalling a text item = studied
* Probability of freely generating it when nothing studied
Results:
Not significant after 30 min
After 1 week, r = 0.45 (20% of variance) more effect on the later than earlier.
What does Bergman & Roediger (1999) show?
Replication + extension study of Bartlett’s study main findings for short stories
15m memory test = major distortions in ~1/3 of all recalled info
Experimental = 15 mins, 1 week + 6 vs control = no 15 mins test
What was the results of Bergman & Roediger (1999) show?
Major distortions were an increasing proportion of memories with repeated retrieval. They were maintained + accurate recall dropped over time.
Control group showed less distorted as well as less accurate recall in absolute terms – although don’t report proportion.
Early test is a ‘double-edged sword’, i.e., errors in immediate recall are remembered later
What does distortions in memory suggest?
Memory = construct than record
They are biased and constructive
What is the overall process of memories
Levels of processing – ‘deep encoding’
Schema and schema-relevant processing
Elaboration = relating to prior knowledge
Organisation effects in list memory
Likely roles of encoding and retrieval factors
How does memory bias and stereotypes link to false memories?
Applications
Allport & Postman (1947) – version of ‘telephone game’ = racial memory bias against Black character
Kleider et al. (2008) = Stereotype errors increased with delay + even neutral suggestion (cues like who did laundry) found stereotype error
What happened in Tran, Hertel & Joorman (2011) study?
Created + modified bias
Training to interpret neutral prose passages positively or negatively
Encode ambiguous novel scenarios
Recall of details from scenarios = biased to trained direction
How does fake news link to bias?
Murphy, Loftus, Grady, Levine & Greene (2019) = N=3140 online study
Memory for real and fake stories before Ireland’s May 2018 abortion referendum
Shown headlines + images relating to stories relating to ‘yes’ and
‘no’ campaigns
For fake stories 48% either “I remember seeing/hearing this” or “I
don’t remember seeing/hearing this but I remember it
happening” (63% if include false belief!)
People more likely to remember fake news consistent with their
own views (group differences: 58% vs. 38% for ‘no’ poster and
40% vs. 30% for ‘yes’ poster)
What is memory source monitoring?
Johnson et al. (1993), Source Monitoring theory
Location = source of memory
* Imagined or real experience (reality monitoring)
* The “ability to specify contextual information surrounding memory traces”
* Not just recollecting context, but evaluating what is remembered – this requires control
What is misattribution?
When you attribute a detail to a different event = memory schema causes distortion + exacerbated by errors
Clinical psychologists + psychology students read
case study vignettes: one simple, one complex-
coherent, one complex-incoherent (in relation to prior
knowledge)
Experts recalled more detail + more false recall of details = not happened
Particularly in the complex-incoherent condition where schema and reality conflicted
Not same age
What is imagination inflation?
When a person though they had done something = imagined event
- 1 ½ minute story from Elizabeth Loftus
- Everyday errors e.g. answering email vs thinking about it
- Imagining = larger effect vs just reading about it - and
applies to common, feasible events and unfeasible events
(Mazzoni & Memon, 2003; see Schacter et al., 2011)
What is content borrowing and why are they so vivid?
People misidentify lure objects sharing perceptual details w/ imagined ones (Henkel & Franklin, 1998)
+
* Misidentifications = reflect actual physical features of seen objects! (Lyle & Johnson, 2006)
Content borrowing from true memories
Extended to DRM task by Lampinen et al. (2006)
while studying word SUGAR: “It is fattening, but it is
good.” While falsely recognising SWEET: “Sweet—old, and
remember, cause I remember liking sweets but thinking they
are gonna make me fat.”
How do avoid false memory?
post-retrieval monitoring - monitoring for details + vividness can only help avoid false memories if false memories = different from true = mixed evidence
Where is control thought supported in the brain?
executive processes in prefrontal cortex
What is the Roomate story study?
Tversky and Marsh (2000)
Study phase: descriptions of ‘annoying, neutral, or cool’ incidents involving 2 roommates.
Interim task: neutral = recount the incidents, positive - write a letter of recommendation, negative - write a letter to student housing requesting their removal.
Test phase: Free recall of original story.
Misinformation effect = distortion introduced after an original event that leads to memory updating (also called suggestibility)
What were the results of the Roomate story study
Ps = written biased letters recalled biased information, i.e. more of the ‘perspective-relevant’ “annoying” or “cool” incidents for that roommate
Added more misattributions consistent with their bias.
What happened in the Loftus and Palmer (1974) car crash study?
Showed = Strong influence on memory of post-event questioning –
potential for misleading information
Speed of the verb used to describe the crash changed how fast they remembered the car was going
What is the strength and weakness of the testing effect?
Benefits of repeated testing (testing effect) ALSO
stronger if longer delay to eventual test
BUT also ‘Retrieval-enhanced suggestibility’. Misinformation
effect, increased by repeated testing, and reduced by long
initial delay
misinformation/ suggestibility errors = involve misattribution
How is eyewitness testimony related to false memories?
About 75% of wrongful convictions in USA involve eyewitness errors
* DNA evidence for wrongful convictions
* Police questioning is critical and can change memory!
Cognitive interview - Geiselman et al. (1985)
Stage 1: Reinstate the context
* Stage 2: Recall events in reverse order
* Stage 3: Report everything
* Stage 4: Describe events from someone else’s
perspective
Stage 2 = reduce schema use
Stage 3 = maximise memory monitoring + to cue further recall
(along with Stage 4).
