The sins of memory Flashcards
Memory failures
- Forgetting your password or PIN versus
- Telling a joke to the person you heard it from
- Accidentally presenting someone else’s ideas as your own
‘Sins of commission’ as well as sins of ‘omission’ – Schacter (1999)
HUGE legal implications in eyewitness testimony!
Deese-Roediger-McDermott (DRM) memory illusion
- Participants study lists of words (they were all associate with sleep but sleep was not one of the words)
- Strong tendency to falsely recognise critical lure as having been presented.
— critical lure- can recall without a prompt of cue
- Vivid memory - people even recall the critical lures!
Medial PFC- knowledge
Schacter et al. (2011)
1- what in study phase
2- what are studied words associated with?
3- what is gist memory
4- memory is?
5- what does gist mean?
1- Gist activation in study phase
2- Studied words are associated in knowledge base with the ‘critical lure’, so they activate the lure in memory
3- Stored memory includes semantically related unstudied content = gist memory
4- memory is both general and specific
5- something that is rather general in its meaning
Explain the critical lure
Because all the words are associated with the critical lure, if you present people with the list of words, then the critical lure will get activated. In this case it’s cold.
People form a memory for the concept that was activated as well as the words that were actually present.
DRM memory illusion:
1- what type of effect?
2- what do errors depend on in people with amnesia?
3- what also reduces this error?
4- what increases the illusion?
5- familiarity of?
1- Strong effect - lures can be recalled as often as studied items!
2- In amnesia, reduced false memory, so errors depend on normal hippocampal function. People with amnesia (where memory is impaired, are less likely to make this mistake. This suggests the hippocampus (which is damaged in patients with amnesia) is necessary in order for these errors to occur).
3- Medial prefrontal cortex damage also reduces this error – consistent with semantic knowledge schemas’ role in errors
4- Dorsolateral prefrontal cortex damage and old age increase the illusion because intact memory control helps avoid it
5- Familiarity of non-presented words – but also FALSE RECOLLECTION
Gist memory for pictures
1- what will you get in the test phase?
2- for categorised pictures, how many false alarms?
3- also called ____?
1- In the test phase, you’ll get some items you’ve seen before, some new items and some lures (relate to the previous item)
2- For categorised pictures, about 20% false alarms on recognition test
3- Also called mnemonic discrimination (discriminating in memory between similar things) and is impaired in ageing and Alzheimer’s
Gist memory for pictures:
1- what are lures?
2- general semantic categories likeness?
3- what is pneumonic discrimination?
1- Lure- related to previous items
2- General semantic categories likeness- more likely to recognise
3- Pneumonic discrimination- discriminating in memory between similar things
Bartlett’s (1932) War of the Ghosts study
Bartlett- Got people to listen to and later recall unfamiliar material. People missed information (omissions) and they changed a lot of the information). He came up with this concept of memory schemas
Bartlett’s memory schemas “the past operates as an organised mass” (1932, p.197)
Memory distortion when to-be-remembered information does not fit our schemas
People recalled unfamiliar stories shorter and distorted – elements changed as well as omitted
Weight of prior knowledge leads you to making mistakes
Methods were not well controlled, no statistics
What were the downsides to Bartlett’s methods?
- Not well controlled
- E.g. deliberate guessing
- NO statistics! (and we need these)
We need more evidence
Avoided separation of memory from meaning used by Ebbinghaus’ (1885)
Ebbinghaus tried to separate memory from meaning – extreme example of how control in the lab may remove the very thing you are interested in
Explain Brewer and Treyens (1981) study on memory for objects in a graduate office
Items rated how well they fit in the office
Objects rated schema-expectancy
Schema-expectancy helped recall of objects
BUT more false recognition of high-schema objects in recognition memory test
Schema expectancy helped people recall objects but it made them have more false recognition (eg. if you had not seen laptop on desk and then asked if you had seen laptop on desk, you were more likely to say you had)
Name a positive about memory and prior knowledge
Prior knowledge can support episodic memory when people process for meaning and when to-be-remembered information fits memory schemas.
NOTE: for clarity, we use ‘gist’ to include ‘associative’ memory errors. The term ‘associative’ also has a different meaning from lecture 1. Here, it is used to refer to the associations between words in semantic memory, and the DRM task specifically.
Name one way that false memories might differ from true memories
If they are based on a vague sense of familiarity
False memories would contain less specific information
Explain Garoff-Eaton, Slotnick & Schacter, 2006
study which looked at true and false memories.
Testing
People had a go at telling the difference between true and false memories
People were asked to study abstract shapes in a scanner
(same as categorised pictures task but with abstract shapes)
Participants scanned during retrieval (a recognition test)
View abstract shapes – distinguish lures from studied
Explain Garoff-Eaton, Slotnick & Schacter, 2006
study which looked at true and false memories.
Results
fMRI activity at retrieval indistinguishable for true vs. false recognition
Suggests that even when we don’t check if false memories are vivid, they might not differ from true memories
BUT we cannot just accept a null finding
ALSO, stimuli were abstract images so no semantic gist
Dennis, Bowman & Vandekar (2012)
Study
fMRI scanning again during retrieval
Focus on subjectively vivid true vs. false recollections
Categorised pictures task that could elicit a memory based on semantic gist – e.g. “yes I saw a cat”
Asked whether the memory was vivid or not
Dennis, Bowman & Vandekar (2012)
Results
Here, they found the true and the false memories did differ significantly
Right hippocampus and early visual cortex both more activated during true recollection than false recollection.
Evidence that true recollection can be different: perhaps more detailed, and containing more sensory information
Differed significantly in visual cortex and hippocampus
Expected there to be less detail in false recollection
These results were inline with the authors prediction because they expected there to be less detail in false recollection
Meta-analysis of studies of false memory retrieval:
1- what regions are commonly activated over studies?
2- what is the bilateral ventrolateral PFC involved in?
3- BUT…
4- no consistent differences in…
1- Several PFC regions commonly activated over studies
2- Included: bilateral ventrolateral PFC – involved in semantic processing so they thought this was connected to semantic gist
3- BUT not all activations differed from true recognition
4- no consistent differences in hippocampus or sensory cortex
What did Kurkela and Dennis (2016) find when they looked at false memory retrieval alone?
They found there were several PFC regions activated
Memory bias and stereotypes:
What did Allport & Postman (1947) and Kleider et al. (2008) show?
Allport & Postman (1947) – version of ‘telephone game’ showing racial memory bias against Black character
Kleider et al. (2008) – gender stereotype errors increased with delay
Creating & modifying bias
Tran, Hertel & Joorman (2011)
Explain study and results
- Training to interpret neutral prose passages - positively or negatively
- After training, participants were also asked to recall details from these novel scenarios.
- Encode ambiguous novel scenarios
- Recall of details from scenarios was biased to trained direction
- Biases can be induced, and affect memory
- Biases may also be modified e.g. in depression/ anxiety
- More errors in in positive scenarios that are positive
- More errors in negative scenario that fit with negative
- Bias induced by training
Training was effective in inducing the intended group differences in interpretive bias. Importantly, participants exhibited memory biases that corresponded to their training condition. These results suggest that manipulating interpretive biases can result in corresponding changes in memory. Findings from this study highlight the importance of future research on the relation among cognitive biases and on the possibility of modifying cognitive biases in emotional disorders.
Fake news and bias study
Murphy et al. (2019)
- Memory for real and fake stories just prior to Ireland’s May 2018 abortion referendum
- N=3140 online study
- 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 10-20% 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)
1- what can bias airse from?
2- what refer to prior knowledge effects?
3- what is memory?
1- prior knowledge, including emotional states
2- Schemas and gist both refer to prior knowledge effects
3- Memory is biased and constructive
Reality (source) monitoring
When and where? The ‘source’ of a memory
Johnson et al. (1993), Source Monitoring theory
- Location on a screen, voice of speaker
- When/ where you met someone
- Where you put your keys
- Imagined vs. real experience (reality monitoring)
- The “ability to specify contextual information surrounding memory traces” (so source ~= context)
- Not just recollecting context, but evaluating what is remembered – this requires control
Reality (source) monitoring
- activation-monitoring theory
- fuzzy trace theory
- what can imagination lead to
Activation-monitoring theory (Roediger) – semantic activation of lure connects it with the study episode. Monitoring retrieval helps but may not prevent.
Fuzzy trace theory - memory for semantic gist different from memory for detail, and if strong gives ‘phantom recollection’ (Brainerd & Reyna)
Imagination can lead us to making convincing memory errors
control before vs after retrieval
Control before retrieval (search) includes mental reinstatement
Control after retrieval (monitoring)
‘Content borrowing’
1- what do false recognitions include?
2- thinking aloud in?
3- words?
4- content borrowing from?
1- actual physical features (colour, shape) of similar seen objects
2- Thinking aloud in DRM task (Lampinen et al., 2006)
3- 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.”
4- Content borrowing from true memories
What did lyle & Johnson study?
Studied black and white line drawings in certain screen locations
What is content borrowing?
Having the same response to a word that wasn’t the original word e.g. thinking about fattening for sweet when really the word was sugar
(Content borrowing sounds a bit like plagiarising someone else’s essay doesn’t it…. And in fact it isn’t that far off the mark)
Cryptomnesia
Unconscious plagiarism as a reality monitoring error
e.g. did you tell your idea to someone or did they tell it to you?
Imagination inflation
Everyday errors e.g. answering email versus thinking about it
Imagining has a larger effect than just reading about something - and this applies to both common, feasible events and unfeasible events
We have vivid imaginations! Imagining has a larger effect
Thinking you’ve replied when you haven’t
In the field: complex errors-
1- how can distortion by a memory schema be exacerbated? + example
2- what did experts do?
3- when did this occur?
4- number of mechanisms?
1- Distortion due to a memory schema can often be exacerbated by misattribution i.e. control failure. E.g. clinical psychologists vs. students read case study vignettes, coherent vs. incoherent with prior knowledge
2- Experts recalled more detail AND falsely recalled more details that had NOT been present!
3-Particularly where schema and reality conflicted
(NB groups differed in age… potentially serious confound!)
4- More than one mechanism even in lab-based DRM and other gist memory tasks
In the field: the Cognitive Interview
Stages
Stage 1: Reinstate the context
Stage 2: Recall events in reverse order (tries to reduce schema use)
Stage 3: Report everything (maximise memory monitoring and to cue further recall)
Stage 4: Describe events from someone else’s perspective
In the field: Misinformation effect
1- influence of?
2- how can influenced memory be accounted for?
1- Strong influence of post-event questioning on memory – potential for misleading information
2- Can be accounted for well by Multiple Memory Trace Theory which also addresses temporal gradient in amnesia
Loftus & Palmer (1974) car crash study
Information introduced in questions about an event is incorporated as part of memory for original event
The way question was asked in car crash study (bumped or smashed) influence the answer
Questions asked post-event gets entangled with the actual event
In the field: Eyewitness Testimony
1- how many wrongful convictions in USA involve eyewitness errors
2- what evidence for wrongful convictions
3- what is critical and can change memory
1- About 75%
2- DNA evidence
3- Police questioning
Bartlett’s (1932) War of the Ghosts:
What were the 2 groups
Experimental group: recall at 15 min, 1 week and 6 months
Control group: no 15 min recall test
Bartlett’s (1932) War of the Ghosts
Results
Major distortions were an increasing proportion of memories with repeated retrieval
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
In the experimental group people remembered more but it was a higher proportion of decorative memories, the repeated retrieval.
So the major distortions need to be maintained more than the accurate information. And this is thought to be because the information was schema in Congress, but also because it was tested on multiple occasions.
The early testing therefore has mixed benefits
A single early test may be worse than none
Major distortions maintained
AND accurate recall drops over time
Major distortions and accurate recall both drop over time
Graesser et al. (1980) - how can recalled text become distorted by prior knowledge?
- Chance of recalling a text item that was studied
- Probability of freely generating it when nothing studied
- Not correlated after 30 min
- After 1 week, r = 0.45 (20% of variance)
BUT: is this representative of ‘real-life’ memory?
Students’ event memory:
what did Wynn & Logie (1998) find
Tested students’ memories for their first week at university every few weeks
- Accurate & stable over a 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 may be less common in ‘naturalistic conditions’
- schema-induced memory distortions may be less common in naturalistic conditions than in the lab.
- But students’ own memories – familiar style and familiar material – didn’t change much over a year
- Initial test was in November so 2-3 weeks not immediate
Unconscious plagiarism
- Discussing your own and other people’s ideas may make them harder to tell them apart
- People made up novel uses for objects (ideas) and experimenter contributed additional uses (Stark & Perfect 2006)
- Elaboration on all the ideas boosted later recall
- BUT participants more likely to recall all ideas as their own!
- i.e., memory updating with memory ‘blending’
NOTE this goes beyond content borrowing because there is an interim memory test after initial encoding
Discussions as may happen in group work
Note only 1 experiment in 32 undergraduates - this could do with replicating…
What kind of information does a recollection (episodic memory) typically contain that is different from a semantic memory?
Context/ contextual information
Information about a specific event / learning episode
What is a mechanism by which an external cue such as a photo can trigger recollection of a previously experienced event?
Context reinstatement
It matches the content of the memory
Match with the memory trace
Pattern completion
What theory explains how processing during memory encoding is related to processing during memory retrieval?
Transfer-appropriate processing
Encoding specificity
