2. Models of Memory Flashcards
Who created the Multi-store model
Atkinson & Shiffrin (1968)
What is the Multi-store model
The multi-store model proposes that memory consists of 3 stores - a sensory register, a short-term store & a long-term store, & info has to move through these stores to become a memory
Journey of information through the Multi-store model
- Info from our environment (eg. visual or auditory) initially goes into our sensory register. You dont really notice much of this stuff.
- However, if you pay attention to it, or think about it, the info will pass into short-term memory
- Short-term memory has a finite capacity & duration. But if info is processed further (rehearsed) then it can be transferred to long-term memory. In theory, the info can then remain there forever
See pg17 for flow chart of multi-store model
Studies that support the Multi-store model
Several studies have been carried out that show that memory is made up if separate stores:
1. The Primacy Effect
2. The Recency Effect
3. Korsakoff’s Syndrome
4. Milner et al
Studies that support the Multi-store model: The Primacy Effect
- Research shows that participants are able to recall the first few items of a list better than those from the middle.
- The multi-store model explains this bc earlier items will have been rehearsed better & transferred to LTM.
- If rehearsal is prevented by an interference task, the effect disappears.
Studies that support the Multi-store model: The Recency Effect
- Participants also tend to remember the last few items better than those from the middle of the list.
- As STM has a capacity of around 7 items, the words in the middle of the list, if not rehearsed, are displaced from STM by the last few words heard.
- These last words are still in STM at the end of the experiment & can be recalled.
Studies that support the Multi-store model: Korsakoff’s Syndrome
- Ppl with Korsakoff’s Syndrome (amnesia that’s mostly caused by chronic alcoholism) provide support for the model.
- They can recall the last items in a list (unimpaired recency effect), suggesting an unaffected STM.
- However, their LTM is very poor. This supports the model by showing that STM & LTM are separate stores
Studies that support the Multi-store model: Milner et al
- Milner et al (1957) carried out a case study into a patient called HM who had suffered from severe & frequent epilepsy.
- His seizures were based in the hippocampus. Doctors decided to surgically remove part of the brain around this area.
- The operation reduced his epilepsy, but led to him suffering memory loss. He could still form short-term memories, but was unable to form new long-term memories.
- This case study supports the idea that different types of memory are separate systems in the brain
Evaluation of the Multi-store model: PROS
Several studies have been carried out that show that memory is made up if separate stores
Evaluation of the Multi-store model: CONS
Although theres lots of support for the model, theres plenty of criticism too:
1. In the model, info is transferred from the STM to LTM through rehearsal. But in real life, ppl dont always spend time rehearsing, yet they still transfer info into LTM. Rehearsal is not always needed for info to be stored & some items cant be rehearsed, eg. smells
2. The model is oversimplified. It assumes there is only one long-term store & one short-term store. This has been disproved by evidence from brain damaged patients, suggesting several different short-term stores, & other evidence suggesting different long-term stores
Who developed the Working memory model
Baddeley & Hitch (1974)
What is the Working memory model
- Baddeley & Hitch (1974) developed a multi-store model of STM called the ‘working memory model’.
- Their model proposed that STM, rather than being a single store, is an active processor which contains several different stores.
Components of the Working memory model
The central executive is a key component & can be described as attention. It has a limited capacity & controls ‘slave’ systems that also have limited capacity:
1. The phonological loop holds speed-based info - its made up of a phonological store (the inner ear) & an articulatory process (the inner voice, which rehearses info by repeating it).
2. The visuo-spatial sketchpad deals with the temporary storage of visual & spatial info.
3. The episodic buffer (which was added to the model in 2000) briefly stores info from the other subsystems & integrates it together, along with info form LTM, to make complete scenes or ‘episodes’.
See pg18 for diagram of Working memory model
What did Baddeley & Hitch base their Working memory model on
The Working memory model came from experimental evidence. Baddeley & Hitch based their model on results from studies that used “interference tasks’:
1. If participants are asked to perform 2 tasks simultaneously that use the same system, their performance will be affected. (saying ‘the the the’ whilst silently reading smth is difficult)
2. According to the working memory model, both these tasks use the phonological loop. This has limited capacity, so it cant cope with both tasks. Performance on one, or both tasks, will be affected.
3. However, if the 2 tasks involve different systems, performance isnt affected on either task. (saying ‘the the the’ whilst tracking a moving object)
Evaluation of the Working memory model: PROS
- Shallice & Warrington (1974)
- Gathercole & Baddeley (1993)
- The model had less emphasis on rehearsal than the multi-store model of memory. Rather than being the key process, rehearsal is just one possible process in the working memory model. This can therefore help explain why, in real life, some things end up in our LTM even though we haven’t rehearsed them - it suggests that other processes are at work.
Support for the Working memory model (PROS): Shallice & Warrington (1974)
Shallice & Warrington (1974) found support for the working memory model through their case study of KF:
- KF was a brain-damaged patient who had an impaired STM. His problem was w immediate recall of words presented verbally, but not w visual info.
- This suggested he had an impaired articulatory loop but an intact visuo-spatial sketchpad, therefore providing evidence for the working memory model’s views of STM.
- This finding could not have been explained using the multi-store model, which proposed the STM was just one system
Support for the Working memory model (PROS): Gathercole & Baddeley (1993)
Gathercole & Baddeley (1993) reported on a laboratory study which supports the model:
- Participants were split into two groups. All of the participants had to carry out a task where they had to follow a moving spot of light. This would use the visuo-spatial sketchpad.
- At the same time, one group of participants also had to describe the angles on a letter - another task involving the visuo-spatial sketchpad.
- The other group of participants were given a 2nd task that would use the phonological loop - they had to do a verbal task whilst following the light.
- Gathercole & Baddeley found that performance was much better in the participants doing tasks which used separate systems
Evaluation of the Working memory model: CONS
The Working memory model is currently the main model of STM, but some psychologists have criticised it:
1. They think the Baddeley & HItch’s idea of a central executive is simplistic & vague. Their model doesnt rlly explain exactly what the central executive is, apart from being involved in attention. However, it’s difficult to design tasks to test the central executive.
2. The model only explains how info is dealt w in STM. It doesnt explain how info is trasnferred to LTM.
3. Much of the research which has supported the Working memory model has been laboratory studies. This reduces the ecological validity of the evidence, as highly controlled studies might not be representative of what happens in the real world.
The Working memory model: Central executive
- Key component in model
- Functions:
1. Direct attention to tasks.
2. Makes decision about what the working memory pays attention to, & contrastingly, which issues should be ignored. - Has limited capacity - can only do a limited no. of things at the time.
The Working memory model: Phonological loop
1st slave system
- Limited capacity
- Deals with auditory information & preserves word order - inner ear
- Speech based info
What did Baddeley (1986) state about the Phonological loop
Baddeley (1986) further subdivided the system into:
- Phonological store - holds words heard
- Articulatory process - holds words heard/seen & silently repeated (looped) like an inner voice. This is a kind of maintenance rehearsal.
The Working memory model: Visuo-spatial sketch pad
2nd slave system
- Coding: visual & spatial info stored here (inner eye).
Visual = what things look like
Spatial = relationships between things
- Limited capacity
