2: COGNITIVE Flashcards
Draw the Working Memory Model (WMM)
- CENTRAL EXECUTIVE
- PHONOLOGICAL LOOP
- VISUO-SPATIAL SKETCHPAD
- EPISODIC BUFFER
(definitions of these in textbook)
Evaluate the Working Memory Model (WMM) (8 marks)
Working Memory credible because it’s supported by the dual task paradigm. For example, Baddeley (2003) tested participants’ recall of similar sounding letters (E, G, P, etc) and found they got lower scores than with dissimilar letters (W, X, K, etc). If the Phonological Loop is overloaded, that would explain this.
However, studies supporting Working Memory lack ecological validity because they are unrealistic. Baddeley’s lists of similar sounding words are not an ordinary activity and don’t tell us how memory works in normal situations.
You could apply Working Memory to helping dementia patients by giving them a quiet environment, so that background noise doesn’t confuse them with dual tasking.
Working Memory is a better model than the Multi Store Model. It replaces STM with something more complicated. It fits in with evidence from brain scans and cases like KF and it was updated in 2000 when Baddeley added the Episodic Buffer.
In conclusion, in terms of the development of Psychology over time, Working Memory is the most successful memory model at the moment. It has been changed and improved over the years but it still fits in with what we know about the brain. However, more research needs to be done on the Episodic Buffer which is rather unclear.
Who created the WMM theory and when?
Baddeley and Hitch in 1974
What evidence supports the WMM theory?
The main evidence comes from dual testing:
-Participants in tests get confused by lists of items that sound similar but not by items with similar meaning. This suggests that the Phonological Loop codes acoustically and gets over-loaded. For example, Baddeley (2003) found that similar-sounding letters (eg V, B, G, T, P, C) are not recalled as well as dissimilar sounding letters (eg W, X, K, R, Y).
-Memory recall of words is ruined if participants are asked to recite irrelevant words aloud at the same time. This also seems to block the Phonological Loop.
-Nelson Cowan (2005) suggests that Working Memory can be more efficient if it “chunks” information together; his experiments show that Working Memory in humans only handles 4 “chunks” at a time.
Some evidence comes from brain scanning:
-The Phonological Loop seems to be located in the left hemisphere, specifically in the temporal lobe
-The VSSP is in the right hemisphere, with simple tasks in the occipital lobe and complicated ones in the parietal lobe.
-The Episodic Buffer seems to be in both hemispheres (bilateral) but particularly in the hippocampus (which links to the Schmolck et al study)
-The Central Executive seems to be linked to the frontal lobes
How does the case study of KF support the WMM?
The KF Case Study supports Working Memory. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF struggled to process verbal information but his visual memory was unaffected. This shows that visual information (VSSP) is processed separately from verbal information (phonological loop).
What are some negatives to the WMM?
New data has emerged which the original (1974) model couldn’t explain – such as the brain-damaged patients who could repeat complex stories. However, the addition of the Episodic Buffer (2000) does improve the model. More research needs to be done on the Episodic Buffer because, unless the other two slave systems, it isn’t completely clear what it does.
The model is based on lab experiments involving dual tasks. These are quite artificial. In real life, even at cocktail parties, you use your other senses (such as paying attention to body language or lip-reading when someone speaks). If the experiments into Working Memory lack ecological validity, then the model won’t explain how memory works in real life situations.
Lieberman (1980) criticises working memory by pointing out out that blind people have spatial memory (they can remember where things are and not bump into them) even though they have never had any visual information. Lieberman argues that the VSSP should have two different components: visual memory and spatial memory.
How can we apply the WMM to real life?
Working Memory tells us how to improve our memory in some situations. If you have to encode something in one particular way (like listening to a radio broadcast) then remove competing information (by muting the TV). However, it suggests you can concentrate on two differently coded sources at once – so you can do revision by copying a mind map while listening to a podcast.
The model may have application to helping people with dementia. Using the Episodic Buffer seems to help people who cannot encoded memories in LTM or have trouble retrieving LTM. This means using Cognitive Stimulation: playing an old song and asking the patient to tell the story of how they first heard it.
Draw the Multi-store Model (MSM)
- SENSORY REGISTER
- SHORT-TERM MEMORY
-LONG TERM MEMORY
(see textbook)
Who developed the theory of the MSM and when?
Atkinson & Shiffrin (1968)
What is the encoding, duration and capacity of STM, LTM and sensory?
SENSORY: encoding - sense-specific duration - 0.5 seconds capacity - limited to 1 sensation STM: encoding - mainly acoustic duration - 15-30 seconds capacity - up to 9 (7 +- 2) LTM: encoding - mainly semantic duration - unlimited capacity - unlimited
What are the three stages of memory?
Encoding > Storage > Retrieval
What is some evidence for MSM?
A lot of research into the Rehearsal Loop uses the Brown-Peterson Technique. This involves blocking rehearsal by getting participants to do an interference task like counting backwards in threes (eg 54, 51, 48…). Participants might learn meaningless information (like three-letter trigrams such as BHK) then perform the interference task for different durations. Participants forget most trigrams after 9 seconds of interference and almost all of them after 18 seconds. This tells us the duration of STM.
Miller (1957) did an earlier study into “the Magic Number 7, plus or minus 2”. He found that STM has a capacity of 7 items (or “bits”) of information comfortably, but struggles to hold more than 9. Miller found that “bits” of information can be grouped together into “chunks”. STM can hold more information in chunks, but loses accuracy (eg recalling a whole face instead of remembering eye colour).
Glanzer & Cunitz (1966) did another early study into forgetting. Asked to recall a list of words in any order, participants tended to recall more from the beginning/end of the list and fewer from the middle. This is the primacy/recency effect. It happens because primacy words are well-rehearsed and encoded in LTM, recency words are still in the Rehearsal Loop; middle words are displaced by recency words because of the limited capacity of STM. This is known as the Displacement Theory of forgetting.
Apply the MSM to real life.
Eyewitnesses see events like crimes or accidents first hand but they are notoriously unreliable when they report on what they saw. There are many people in prison because they were falsely accused by eyewitnesses. Gary Wells (1996) reports the case of Ed Honacker who served 10 years for rape, after the victim identified him as her attacker. He was released in 1994 when DNA evidence proved his innocence.
This might happen because of inattention. If eyewitnesses are distracted, key details might not reach STM. Other details might not reach LTM if they are not rehearsed – if the victim refuses to think about or talk about the crime because it was so traumatic, they won’t rehearse the information, at least not Elaborate Rehearsal.
During a traumatic event, the eyewitness might not want to “chunk” the information, blotting out the “big picture” and focussing on individual details (eye colour, shape of nose); this makes misidentification more likely.
Describe the cases of Clive Wearing and HM, relate this to the MSM.
Clive Wearing received brain damage to his hippocampus after a viral infection. His case study is reported by Colin Blakemore (1988). Clive Wearing could still use his STM to remember things for about 20 seconds but then he would forget everything – he could not “make new memories”. The Multi Store Model can be applied to his case, because it suggests an inability to rehearse information into LTM.
A similar case was H.M., a young man who had brain surgery in 1953 to cure his severe epilepsy. When the hippocampus was damaged, H.M. was left unable to make new memories. However, he still had a lot of memories from before his surgery, which suggests he still possessed LTM, but could no longer add to it. He died in 2008 and his real name was revealed to be Henry Molaison. H.M. is studied in more detail in the Contemporary Study by Schmolck et al. (2002).
Evaluate the Multi-store Model (MSM). (8marks)
MSM is credible because it is supported by case studies of people like H.M. and Clive Wearing. Because of brain damage, these people have amnesia and cannot make new memories. MSM suggests they fail to rehearse information from STM to LTM.
However, there are objections based on cases like Shallice & Warrington (1970). They report that K.F. who lost STM in a crash, could still make new LTM memories. MSM can’t explain this.
Most of the studies into MSM lack ecological validity because the Brown-Peterson Technique is unrealistic. Learning lists of trigrams is not an ordinary activity. This means the model is based on research that lacks ecological validity.
MSM can be compared to Working Memory. It is more simplistic than Working Memory, because it doesn’t split STM up into acoustic and visual systems.
In conclusion, MSM was a very influential memory model but psychology has progressed over time and it has been replaced by more complex ones like Working Memory and Levels of Processing Framework. Shiffrin added Elaborative Rehearsal to MSM to try to bring it up to date, so even he must recognise this.
What research supports the MSM?
There’s a lot of research in support of the Multi Store Model, particularly into the primacy/recency effect and rehearsal. Studies like Glanzer & Cuntiz (1966) show how memories are displaced from STM when they exceed its capacity, which Miller (1957) shows to be 7 ±2 “bits” or “chunks”.
There’s also a lot of support from case studies of unusual individuals like H.M. or Clive Wearing. The Multi Store Model explains their disability as a failure to rehearse information, preventing them from encoding information in LTM.
The theory also has credibility on a commonsense level (what is called face validity): it describes quite well what memory feels like, with some things being remembered for years but other things disappearing from your memory moments after they happen.
What are some negatives to the MSM?
Although H.M. and Clive Wearing seem to back up the Multi Store Model, other evidence contradicts it. Shallice & Warrington (1970) report a victim of a motorbike accident (K.F.) who could still add memories to LTM even though his STM was so damaged he couldn’t repeat back more than 2 digits. MSM cannot explain this but K.F.’s unusual condition does support the Working Memory Model.
The model is based on lab experiments involving tasks like the Brown-Peterson Technique. These are quite artificial, often involving meaningless trigrams. In real life, you use your memory to recall information that is important to you and there are usually consequences if you forget. If the experiments into MSM lack ecological validity, then the model won’t explain how memory works in real life situations.
What is the difference between procedural memory and declarative memory?
Tulving makes a distinction between different types of LTM: procedural memory and declarative memory.
Procedural memory is the memory of how to do things. It includes tying shoelaces, writing, tapping in your banking PIN and using a knife and fork. You may retain procedural memories even after you have forgotten being taught to do these things in the first place.
Declarative memory is the memory of meaningful events. You might remember being taught to play the guitar, even if you’ve forgotten how to do it.
Describe episodic memory.
Episodic memory is the memory of particular events and specific information: events, names and dates. It includes memories of things that have happened to you and information like a person’s address.
Episodic memories seem to be perceptually encoded – they are linked to the 5 senses which is why they can be triggered (“cued”) by a sight or a sound or a smell. Tulving gives examples like remembering he has an appointment with a student the next day or recalling words from a list studied earlier as well as autobiographical memories (remembering details from your own past).
Describe semantic memory.
Semantic memory is the memory of relationships and how things fit together. It includes the memory that you have brothers or sisters, where things are located and what they do.
Semantic memory is needed for language because words have meaning – learning words in the first place involves episodic memory but once they are learned they go into the semantic store. Tulving gives examples like knowing that summers are hot in Kathmandu and knowing that July is the month after June.
Describe the case study of Clive Wearing.
Clive Wearing is a musician who suffered brain damage from a viral infection (herpes simplex encephalitis) in 1985. He suffered almost complete amnesia. He also lost the ability to encode new long term memories. Clive Wearing forgets everything within 30 seconds and is always “coming into consciousness”, feeling he is waking up for the first time.
However, although Clive Wearing has lost his episodic memory, he still has semantic memory. When his wife Deborah enters the room he greets her joyously, believing he hasn’t seen her for years or even that they are meeting for the first time (even if she has only been gone for a minute). Although he has no episodic memories of Deborah, he has semantic knowledge of her: he remembers that he loves her.Similarly, although he cannot remember their names or ages, Clive Wearing knows that he is a father and that he has children.
Clive Wearing also has intact procedural memory. He can still play piano and conduct a choir – although he cannot remember his musical education and as soon as the music stops he forgets he was performing and suffers a shaking fit.
Sir Colin Blakemore (1988) carried out a case study on Clive Wearing. Blakemore discovered that damage to Clive Wearing’s brain had been to the hippocampus, which seems to be the part of the brain where the Short Term Memory (STM) rehearses information to encode it into LTM.
Apply research into the LTM to dementia.
The most common symptom of dementia is difficulty to make new memories. STM (which rehearses information) is the first type of memory to go. Episodic memory is the next to go, as sufferers begin to forget autobiographical events. Usually, recent episodes are lost first, but sufferers still remember episodes from their young adulthood and youth. Semantic memory is lost later, when sufferers struggle with language and no longer recognise family members. As the disease advances, parts of memory which were previously intact also become impaired. Eventually all reasoning and language abilities are disrupted.
Patients tend to display a loss of knowledge of semantic categories. Initially, they lose the ability to distinguish fine categories, such as species of animals or types of objects, but, over time, this lack of discrimination becomes more general. At first, a patient with advanced dementia may see a spaniel and say, “That is a dog.” Later, they may just say, “That is an animal”.
What research supports LTM theory?
There’s a lot of research in support of Tulving’s distinctions. Some of this is case studies of amnesia patients like Clive Wearing who have lost episodic memory but still have semantic memory. The deterioration of dementia patients also suggests that episodic and semantic memory are separate because episodic memory is lost first and semantic memory last.
The Classic Cognitive Study by Baddeley (1966b) also supports the existence of semantic memory. Baddeley found that participants struggled with word lists linked by a common theme, which suggests the semantic similarity confused LTM. Unrelated word lists were not confusing. This suggests at least part of LTM works semantically.
The Contemporary Study by Schmolck et al. (2002) also supports the idea of long term memory being located in a specific part of the brain – the temporal cortex.
Tulving carried out a case study of Kent Cochrane (K.C.) who suffered brain damage in a motor accident in 1981. Like Clive Wearing. K.C.’s hippocampus was destroyed in the injury and he lost all episodic memory. However, K.C. could still remember things he had learned in books, like dates or definitions (such as the difference between a stalagmite and a stalactite) - in other words, his semantic memory was still intact. This is evidence for a difference between episodic and semantic memory.
An example of this is the case study of K.F. who suffered brain damage in a motorbike accident. Like Clive Wearing and K.C., K.F. suffered damage to the temporal lobe which made it almost impossible for him to rehearse new memories. However, Shallice & Warrington (1970) report that K.F. could still remember episodes. This is a problem for the multi store model (on which Tulving’s ideas are based) but it does suggest that episodic memory is a special type of LTM.
What are some negatives about the LTM theory?
It seems as if semantic and episodic memory both rely on each other and might not be all that separate. For example, if you learn that you husband or wife is unfaithful (episodic memory) you will probably trust them less (semantic memory) – which suggests that the two are linked.
Damage to the temporal cortex of the brain seems to cause problems with both types of memory, as does dementia. This suggests declarative and non-declarative memory are located in the same place and may turn out to be the same thing working in different ways.
Squire & Zola (1998) put this to the test. They examined children with amnesia (who never got a chance to acquire a semantic store in the first place) and adults with amnesia (who had semantic and episodic memories from before suffering brain damage). The participants’ episodic and semantic memories seem to be equally impaired which supports the idea that the two memory functions are linked or even the same thing.
What about K.C.? Squire & Zola propose that K.C.’s problems were due to damage to his frontal lobe - in other words, not a problem with his memories as such, more a problem with his ability to understand and make sense of his own memories.
This leads ton the final criticism of Tulving’s ideas - that it’s really hard to define episodic and semantic memory in a measurable way. This means that Tulving’s concepts are not operationalisable..
