Memory and Forgetting Flashcards
What is double dissociation of working and long term memory in brain damage?
- amnesic syndrome (normal working memory but no/little ability to learn new facts/events (anterograde amnesia): e.g. HM had normal 7 digit memory span but couldn’t learn list of 8, normal recency effect but poor recall of earlier items
- short-term syndrome (selective impairments of working memory): e.g. Warrington and Shallice (1969) KF had poor immediate repetition of short word sequences but able to learn them if presented slowly
Declarative versus non-declarative memories?
- anterograde amnesia patients have impaired ability to form new memories for events and facts
- can exhibit normal learning rates in acquisition of perceptual, problem-solving, practical skills
- can have impaired procedural (non-declarative) with unimpaired declarative, can be the result of brain damage
What are the 2 types and definitions of declarative memories?
- episodic (memory for individual autobiographical experiences
- semantic (general and conceptual knowledge)
What is the double dissociation between episodic and semantic memory?
- amnesic patients tend to have anterograde amnesia for both personal episodes and knowledge
- there’s some (KC or Clive Wearing) who can’t recall any personally experienced events but knowledge on maths, history, music, general is well-preserved
- those with semantic dementia show progressive loss of knowledge on the world, can be combined with autobiographical memory
What did research on semantic dementia patients find in regards to episodic memories?
(Adlam et al, 2009)
- days 1 and 2 there were tests of semantic memory (object and sound knowledge)
- day 2 tests of memory on recent episodes
- patients had profound impairment when remembering semantic memories compared to control
How is forgetting measured?
- recall tests: story/events recall, free recall of nameable items list, cued recall, serial recall
- recognition tests: ability to discriminate old from new items
How is forgetting orderly?
- can be described by a simple mathematical function of the retention interval
- is linear, as time passes more is forgotten
What does orderliness of forgetting suggest?
- there’s some inevitable decay process
- the process of loss from storage
How can retrieval failure cause forgetting?
- information may be recalled later with further prompts/cues
- some memories show no loss over time
How does longer retention not necessarily increase forgetting?
- no forgetting of school classmates over 30 years (Bahrick et al, 1975)
- flashbulb memories
- forgetting of former students is more likely from teachers due to seeing more, forgetting increases with interval
How is interference tested against decay theories?
- normally retention interval is confounded with the number of other experiences accumulated during it
- to control the interval they alter experiences (more new learning of similar stuff vs less new learning of similar stuff)
- forgetting due to interference then recall should decrease with more exposure to similar stuff
How is some forgetting clearly attributable to interference?
- participant must learn 10 arbitrary pairings
- learns list 1 then list 2 and given test on one of them
- recall of list 1 was worse when 2 was learned afterwards (retroactive interference)
- recall of 2 was worse when 1 had been learned before (proactive interference)
- retrieval is difficult when other similar material has been learned
What factors influence retrieval?
- processing at encoding/acquisition
- consolidation after encoding
- interference from other memory traces at retrieval
- similarity of encoding and retrieval contexts
What impact does organisation at acquisition have on memory?
- deliberate rote rehearsal increases later recall (rote memory is associated with fact or data, little emotion associated with it)
- primacy effect in free recall but mere rote rehearsal is an ineffective learning strategy
- incidental memory experiments show processing the meaning and actively organising the material are effective learning strategies
What did Mandler (1967) find in organisation at acquisition?
- group 1 and 2 sorted words into 2-7 categories of their devising
- group 1 told to learn words, 2 wasn’t
- no difference in later recall test
- group 3 (placed cards into columns while trying to learn list) remembered less than groups 1 and 2
- organising the material produces effective acquisition, not effort to learn by itself
What did Craik and Tulving (1975) find when looking at depth of processing at acquisition?
- showed series of unrelated words and gave 1 of 3 orienting tasks (upper/lower case, rhyme with…, fit in sentence)
- found they recognised more words when they had to fit word into sentence
- processing the meaning is better than processing surface form
How do mnemonics demonstrate the power of appropriate elaboration at acquisition?
- learning a rhyme for sequence learning, rhyme item relates to the position of something in the sequence
- method of loci: memorising route of familiar building, at each point in the route an idea of something to mention is linked to image
Why do mnemonics help recall?
- learning forms associations, retrieval activates the associations
- bind ideas to pre-established framework that organises them
- imagery encourages formation of rich nexus of associations between hook and concept attached to it
- forces exhaustive retrieval attempts
What occurs in consolidation phase 1?
- after traumatic brain injury or ECT often retrograde memory loss for many minutes
- disruption of process of consolidation of memory trace in hippocampal/media temporal cortex system
- consolidation of novel traces suffers interference from further traces (sleep improves memory for material learned in last few hours, alcohol/barbiturates impair learning but improve it for material learned just before)
What occurs in consolidation phase 2?
- over long timescale, recent LTM traces are more vulnerable to hippocampal damage
- amnesic patients with damage to hippocampus/medial temporal cortex show gradient of retrograde amnesia over years
- re-activation of traces makes them more robust, stored elsewhere in cortex and no longer dependent on hippocampus
What is associative interference at retrieval?
- interference maximal when same stimulus items are used for each list
- competition between 2 associative links from the same retrieval cue
What is the fan effect?
Lewis and Anderson, 1976
- retrieval as example of associative interference
- learn 0-4 new facts about each set of famous people
- later true/false RT measured for test statements
How are the effects of associative interference mitigated?
- the fan effect seems paradoxical
- the facts learnt in the fan effect study were unrelated
- claimed that if facts are thematically related the fan effect is eliminated
- thematic relationship enables learner to form associations between separate facts using pre-existing knowledge schemas (provides multiple retrieval paths)
How does reconstruction impact retrieval?
- we interpret what we see/hear via learned schemas (knowledge of typical patterns/event sequences)
- when remembering we recover fragmentary association from which we reconstruct the event/fact
- fill in the gaps using general knowledge schemas and fragmented episodic sources
What are the effects of context and specificity on retrieval?
- information is more easily retrieved if tested in same context it was acquired in
- Godden and Baddeley (1975) found if they learnt and recalled on land it was better retrieved than it was in water, safe effect for other way around
- sensitivity of retrieval to congruence with the internal context at the time of learning is sometimes called state-dependent learning
- similar effects of induced sad and euphoric moods
- encoding-specificity is causal in the maintenance of depression: negative memories are more accessible in the depressed state, their retrieval reinforces the depression
Why is it easy to create false memories?
- source amnesia is common: retrieval of information coupled with inability to remember it’s sources
- recall is constructive: fragments of actual experience recovered from memory are combined with other information in memory which has lost source
What did the Loftus eye-witness testimony experiments find?
- mis-information implied by interrogation after event is incorporated into reconstruction of event
- if word smashed was used in questioning they estimated higher speed of the car then words such as collided or hit etc