Remembering and Forgetting Flashcards
What are the different types of information we are able to store long term?
- Episodes: temporally distinct past experiences
- Knowledge: word meanings, facts, categories etc.
- Skills and abilities: effects of past experience demonstrated via performance
What sort of information does our memory for episodes tend to contain?
spatial and temporal contextual information
What does our memory for meanings of things not tend to include?
spatio-temporal context (you don’t remember the context in which you learnt it)
What is Tulving (1980s) LTM model?
- Separates long term memory into different levels of consciousness:
- Episodic: autonoetic (self-aware, e.g. a memory from primary school)
- Semantic: Noetic (aware of info, not origin)
- Procedural: anoetic (unaware, e.g. riding a bike)
- Episodic, semantic and procedural memories are interactive and defined by levels of conscious awareness
Why is the ability to disconnect information from the context in which it was learned a useful property for a memory system?
It saves on storage
What does Tulving’s model distinguish between?
- distinguishes between memory systems and tests
Episodic or ‘direct test (e.g. recognition memory for previously presented items) is intended to measure episodic memory system
BUT some episodic tests can be influenced by non-episodic memory systems:
You can ‘know’ that you have seen an item recently without consciously ‘remembering’ the encoding event (e.g. you find it familiar but don’t recollect it
In episodic memory what is memory for events and experiences tied to?
A specific time and place
What are the typical types of episodic memory tests?
Free recall
Cued recall
Recognition
How is episodic memory dissociated from other memory systems?
Impaired in amnesic syndrome: can’t store new episodic memories, but can learn new procedural skills
what is semantic memory?
General knowledge of objects, word meanings, facts, people without connection to a specific time and place (generic memory)
What are the typical types of semantic tests?
Word definition
Object naming/ definition
Category fluency (animals: how many in 60 seconds)
Matching tests
How does semantic memory dissociate from other memory systems?
Semantic dementia (progressive loss of semantic knowledge)
In Semantic dementia Episodic memory less affected; procedural memory preserved
What is procedural memory and how is it acquired?
- Knowledge of how to do things; skills; ‘blueprint’ for action
- Acquired through multiple trials, learning by doing
What are the typical types of procedural memory tests?
Pursuit rotor (tracking); mirror drawing (tracing); skill learning
How does procedural memory dissociate from other memory systems?
Largely preserved in amnesia and semantic dementia
How does H.M’s mirror drawing task (Milner 1962) show that episodic and procedural memory are different?
- Amnesic patients can learn to perform ‘procedural’ tasks despite complete lack of (episodic) memory for training
- H.M learnt how to mirror draw
- he didn’t remember previously learning it
- but still had the skill
- his errors decreased exponentially each day
What is priming?
Improvement (speed/accuracy) in processing a stimulus (identification/ production/ classification) as a result of a prior encounter with the same or a related stimulus
What are the different types of test for priming?
Perceptual identification (name an object from image obscured by noise)
- You will need to get rid of less of the noise if you have already seen the images
- Amnesics show this effect as well
Word-stem/fragment completion (first word that comes to mind)
- People more likely to complete with words they have seen from the study faze
- Amnesics will also show this effect
Sentence completion (‘conceptual’ priming)
- e.g. ‘the transplant surgeon removed the patient’s….’
- More likely to use a word you have heard recently
How does priming dissociate from other memory systems?
Largely preserved in amnesia
What is evidence for the fact the there are two different systems for priming and episodic memory?
- Amnesic patients generally show intact perceptual priming
Perceptual identification: identify studied items faster/ better than unstudied items
Recognition memory tests: perform better under indirect instructions (‘go with your gut feeling’) - Right occipital lobe resection (patient MS, Gabrieli et al. 1995)
Showed normal declarative memory (recall, cued recall, recognition), impaired perceptual priming
Double dissociation: opposite to amnesic patients
What is Squire’s contemporary model of LRM systems?
- Episodic and semantic memory = declarative (explicit) memory Facts (semantic) Events (episodic) You can retrieve it - Procedural and priming = nondeclarative (implicit) Procedural (skills and habits) Priming Simple classic conditioning Emotional responses Skeletal musculature
What was Penfield’s experiment (1958)about retrieval and what did this lead him to argue?
stimulating the temporal lobes of patients often elicited trivial ‘memories’
He argues that the brain retains a permanent record of all experiences
40 of 520 patients had ‘memories’ evoked, and most of these resembled dreams
What is Ebbinghuas (1885) experiment for his forgetting curve?
- Learned 169 separate lists of nonsense syllables
- Relearned each list after an interval of 21 mins to 31 days
- Time required to relearn list (to 100%) = measure of forgetting
- Information of loss is rapid then levels off: a logarithmic function which holds for many different types of learned material
What were the two early hypotheses about forgetting?
- Decay: memory simply fades with time
- Interference: memory traces disrupted or replaced by subsequent/ prior learning
What was Minami and Dallenbach’s Cockroach study (1946)?
- Cockroaches trained to avoid electric shock
- 24 hours later (allowed to move freely): 70% forgetting
- BUT cockroaches that were immobilised (crawl into dark cone, freeze) for 24 hours after learning: only 25% forgetting
- evidence for interference
What is retroactive interference?
- Later learning disrupts earlier learning
- Memory decreases as the number of intervening trials increases
What is Slamecka (1980) experiment for retroactive interference?
read sentences 8 times followed by rest or 4 or 8 trials of equivalent sentences
- Amount of original sentences forgotten as a function of number of intervening trials (RI)
- Number of intervening trials critical - not just time
What is proactive interference?
- Prior learning disrupts subsequent learning
- Interference builds up over trials
- with similar stimuli
What Have Underwood, Keppel and Wickens found about retroactive interference?
- Performance declines over successive study-tests with similar stimuli
- Performance recovers when switch to dissimilar stimuli: release from proactive interference (Wickens, 1970; MacLeod, 1975)
- When category changed after interference builds up, performance jumps
Why does proactive interference lead to forgetting?
Assume a cue has a fixed capacity for activating memories – the more memories associated with that cue, the less well it can activate any of them
Or (flipside): if several possible memories share similar overlap with retrieval environment, successful recall less likely
What did Tulving (1974) say were the two major reasons for forgetting?
- trace-dependent forgetting (= decay, deterioration)
- cue-dependent forgetting (failure of retrieval)
What improves retrieval performance and makes retroactive interference weaker?
Cueing
What was Tulving and Psotka’s (1971) experiment about cued/ free recall and what did they find?
- Several word lists studied and tested one at a time
- At end of experiment, memory for 1st list tested
- Recall declines as the number of lists presented after original learning increases (retroactive interference)
- RI selectively affects free recall (no cue)
- Cued recall/ recognition less affected because context is (partly) reinstated during test
What was Tulving’s (1979( encoding-specificity principle?
- Retrieval success depends on ‘informational overlap’ between encoding (study) and retrieval (test)
- Similar to transfer appropriate processing, but about context rather than processing
- Context can be intrinsic or extrinsic
What is intrinsic context?
Features that are an integral part of target stimulus
what was Barclay et al (1974) experiment on intrinsic context?
- Effect of study-test congruence on memory for target words:
- Study:
The man tuned the piano (vs the man lifted the piano) - Cued recall:
‘something melodious’ (congruent with ‘man tuned piano) -> 4.6 words recalled
‘Something heavy’ (incongruent with ‘man tuned piano’) -> 1.6 words recalled - Recognition cues were better if study and test intrinsic context were similar
What is extrinsic context?
- Other features present at the time of encoding (time, place, cognitive state)
What was Godden and Baddeley’s (1975) Diver study experiment?
- Study: list of words
On land or
Underwater - Test free recall and recognition
On land or underwater - Significant test type x encoding context interaction (Study underwater lead to better recall underwater and vise versa)
- However recognition doesn’t show that interaction: recognition always better for dry land. This is because recognition has strong intrinsic cues
What did Freud (1901) believe in regards to forgetting?
People actively (/unconsciously) repress unpleasant memories
What was Levinger and Clark’s (1961) experiment to support Freud’s forgetting theory?
- word association task with neutral and negative words. - Recall of association tested after 4-month delay:
Ss remember fewer negative word associations than neutral one
Evidence for repression of emotional memories?
What is the contrary evidence to Freud’s forgetting theory?
Parkin et al (1982) repeated word association study with immediate recall & 1-week delay:
Immediate: neutral > emotional; 1 week: emotional associations better remembered
Evidence against selective repression of emotional material?
- Further contrary evidence
Memory of childhood abuse (Williams, 1994): those who suffered more abuse are most likely to remember
What is Mike Anderson’s ‘think/no-think paradigm?
Learning phase: participants learn cue-target pairs of words to criterion
Think/No-think (TNT) phase: cue words are shown one at a time, in either green or red font
Green = think (participants silently retrieve the target word and think about it)
Red = no-think (participants try to prevent the target word from coming to mind
Test phase: cue words presented, participants recall target word, regardless of whether cue was red or green or not shown in the T/NT phase
Found that recall is worse if item was suppressed in the no-think phase
What was Emily Holme’s Tetris studies?
Engaging in a visuospatial task (playing Tetris) after a traumatic event (in the lab: watching a traumatic film) can reduce ‘flashbacks’ (intrusive memories) over 1 week
What is the physiological basis of memory?
glutamate release, protein synthesis, neural growth and rearrangement
What does consolidation of memories do?
- ‘Fixes’ information in long-term memory, strengthens connections between cortical regions over hours, days, months (‘systems’ consolidation)
- Over time, cortical components of memories become less dependent on hippocampus for retrieval (hence HM can retrieve old memories)
Why can’t HM recall events in the lead up to surgery?
New memories are initially labile (sensitive to disruption) before becoming progressively more stable as they are consolidated
Will all memories be consolidated?
No. Consolidation is selective
What is Nadet et al (2000) recent work on reconsolidation?
- Reconsolidation can be ‘blocked’ or altered to e.g. remove emotional association
Extinction
Pharmacological intervention - Possible use as a treatment for PTSD, phobias
Give a summary of forgetting
• Forgetting can occur as a result of
- Decay (maybe? – difficult to prove and explain)
- Interference (pro – or retro-active)
- Retrieval failure (context/ cue-dependent)
- Repression (maybe?) or motivated forgetting
- (Re-)consolidation failure (or non-selection)
• Most ‘accepted’ idea is that some combination of these, mainly cue-dependent forgetting (retrieval failures and consolidation failure account for most forgetting
Give a summary of memory
• Memory can be defined by store
- Sensory stores
- short-term stores
- long-term store
• by process
- Short lasting effects of neural/perceptual/ informational processing
- Medium-duration effects of ‘working’ memory
- Long-term effects of processing at different depths
• Or by content system:
- Declarative: episodic, semantic
- Non-declarative: procedural, priming, etc.
