Atkinson And Shiffrin 1968 Case Study

This is a key theory for Unit 1 and you need to know it in detail. This includes all the parts of the model, the research supporting it and strengths and weaknesses. Shiffrin's addition of the Elaborative Rehearsal is not in the Specification, but should be learned by students aiming for the top band. Make sure you can apply the model, explaining how it accounts for ordinary remembering and forgetting.

ATKINSON & SHIFFRIN (1968)
MULTI STORE MODEL EXPLAINS MEMORY AND FORGETTING

This theory was developed by Richard Atkinson & Richard Shiffrin (yes! they were both named Richard!). It is sometimes called the “Three Stage” memory model because it is a linear model of memory that proposes three distinct memory stores that have different characteristics: Sensory Memory, Short Term Memory (STM) and Long Term Memory (LTM). The theory was around for decades before Atkinson & Shiffrin brought all the research together and wrote it up, which is why you will be looking at some studies from the '50s and early '60s as well.

This theory is significant for students in other ways:
  • It shows how scientific research proceeds. Before Atkinson & Shiffrin, memory had been viewed as learned behaviour (ie classical conditioning) but these researchers moved research towards the idea of information processing. This was part of the “Cognitive Revolution” in Psychology in the late ‘60s and ‘70s.
  • It illustrates features of the Cognitive Approach, since it expresses the processes of memory as a diagram or flowchart, which resembles the sort of information processing used by a computer
  • It ties in to your Key Question in Cognitive Psychology, since it helps explain Alzheimer’s
  • It is important for you to understand how Working Memory and Tulving’s research into Declarative Memoryfurther develops this model

THE THREE STAGES OF MEMORY

Memory is viewed as information which comes from our environment through the 5 senses. It is stored (briefly) in Sensory Memory, which lasts less than a second. If information is attended to, it flows into STM, which has a duration of up to 20 seconds. If it is rehearsed, it is encoded in LTM which has an unlimited duration.
Information can be retrievedfrom LTM and brought back into STM. Information can be recalledfrom STM and brought into the conscious mind. The rehearsal loop stores up to 9 items of information and the more often information is “looped” through the STM, the more securely it is rehearsed.
  • Atkinson & Shiffrin focused on two types of encoding: acoustic (sound) and semantic (meaning). They found the STM works mostly by acoustic encoding; LTM uses all types of encoding but favours semantic

RESEARCH INTO THE MULTI STORE MODEL
The findings of studies

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-lettertrigrams 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.
Atkinson & Shiffrin originally proposed that the Rehearsal Loop worked by repeating (looping) information over and over. This is Maintenance Rehearsaland it is similar to rote learning.

Raaijmakers & Shiffrin (2003)later proposed another type of rehearsal – Elaborative Rehearsal. This involves semantic encoding by thinking about the meaning of information. This is similar to creating mind maps and is more effective for encoding information in LTM than Maintenance Rehearsal.

APPLYING THE MULTI STORE MODEL (AO2)
MEMORY in the real world

Eyewitnesses

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 Honackerwho 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.
Clive Wearing & H.M.

Clive Wearingreceived 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.
This short video introduces you to Clive Wearing. The Youtube title is misleading. Clive Wearing has STM; it's encoding memories into LTM that he cannot do
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).

EVALUATING THE MULTI STORE MODEL (AO3)
CODA

Credibility

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.

Objections

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.

Differences

The Multi Store Model can be compared toWorking Memory (Baddeley & Hitch, 1974). Working Memory replaces STM in the model and provides a more detailed explanation of rehearsal and retrieval from LTM. Most psychologists consider Working Memory to be an improvement and a refinement on the (rather simplistic) Multi Store Model.
Reconstructive Memoryis a different approach to memory involving schemas. This theory explain why we mis-remember things (false memories), which the Multi Store Model doesn't explain. However, in Working Memory it is the Central Executive that creates and retrieves schemas to help the slave systems do their jobs. This is another example of Working Memory incorporating and improving on the Multi Store Model.

A different theory of memory is Levels of Processing Framework (Craik & Lockhart, 1972). This theory ignores separate stores altogether. It suggests that encoding a memory is about the “depth” of processing. Semantic encoding is much “deeper” than acoustic or visual encoding, making this information easier to remember. We also have much more capacity when we try to store meaningful things: most people can only store up to 9 numbers or trigrams but they can store up to 20 words. Richard Shiffrin used this idea when he introduced Elaborative Rehearsal to the MSM in 2002.

Applications

The Multi Store Model of Memory tells us how to improve our memory in some situations. If you are an eyewitness then you need to pay close attention to encode information in STM. You then need to rehearse it. Repeating the information over and over works, but Elaborative Rehearsal is better because it encodes information semantically. For example, students should make mind maps or use colour coding to focus on meaning.

The model may have application to helping people with dementia or brain damage. If patients struggle to rehearse new information, then writing things down and putting labels on things will help. Colour coding buttons on phones or remotes will also help because it brings in Elaborative Rehearsal.
Start with an evaluation point and back it up with evidence.
Evaluation + evidence = "logical chain of reasoning"
Issues & Debates (like psychology over time) make great conclusions

EXEMPLAR ESSAY
How to write a 8-mark answer

Evaluate the Multi Store Model of memory. (8 marks)
  • A 8-mark “evaluate” question awards 4 marks for AO1 (Describe) and 4 marks for AO3 (Evaluate).

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.
Apply the Multi Store Model of memory.
  • A 4-mark “apply” question awards 4 marks for AO2 (Application) and gives you a piece of stimulus material.
Ashleigh and Callum are buying sweets in the corner shop when they see a car drive past and crash into a lamp post. A lot of people run into the street to help. Later on, a journalist asks them to describe the event! To their surprise, they both give very different accounts of what happened.

Using your knowledge of psychology, explain why their memories are different. (4 marks)

MSM would explain Ashleigh and Callum’s different memories because they might have been paying attention to different things. If you don’t pay attention to something, it is forgotten as soon as it leaves the Sensory Memory.
Even if they paid attention to the same thing, they might not both have rehearsed it. If Ashleigh talked about it or thought about it afterwards, she would be more likely to have the memory in LTM.
With so much going on, their STM might have been overloaded. STM has a capacity of up to 9 items so some details may have been missed.
Displacement Theory means Ashleigh and Callum should remember details from the beginning and end of the accident (primacy/recency), but they might forget different details from the middle.
  • To get 4 marks for AO2, I’m making 4 clear and different applications of Multi Store Model.
  • I’m writing 4 paragraphs, hoping to get a point for each. Because this isn’t a 8-mark or 12-mark essay, I don’t need a conclusion. Just the 4 points will do

Multi Store Model of Memory

Saul McLeod published 2007


The multistore model of memory (also known as the modal model) was proposed by Atkinson and Shiffrin (1968) and is a structural model. They proposed that memory consisted of three stores: a sensory register, short-term memory (STM) and long-term memory (LTM).

Information passes from store to store in a linear way, and has been described as an information processing model (like a computer) with an input, process and output.

Information is detected by the sense organs and enters the sensory memory. If attended to this information enters the short term memory.

Information from the short-term memory is transferred to the long-term memory only if that information is rehearsed (i.e. repeated). If maintenance rehearsal (repition) does not occur, then information is forgotten, and lost from short term memory through the processes of displacement or decay.


The Memory Stores

Each store is a unitary structure and has its own characteristics in terms of encoding, capacity and duration.

Sensory Memory

    • Duration: ¼ to ½ second

    • Capacity: all sensory experience (v. larger capacity)

    • Encoding: sense specific (e.g. different stores for each sense)

Short Term Memory

    • Duration: 0-18 seconds

    • Capacity: 7 +/- 2 items

    • Encoding: mainly auditory

Long Term Memory

    • Duration: Unlimited

    • Capacity: Unlimited

    • Encoding: Mainly Semantic (but can be visual and auditory)


Key Studies

Glanzer and Cunitz showed that when participants are presented with a list of words, they tend to remember the first few and last few words and are more likely to forget those in the middle of the list, i.e. the serial position effect.

This supports the existence of separate LTM and STM stores because they observed a primacy and recency effect.

Words early on in the list were put into long term memory (primacy effect) because the person has time to rehearse the word, and words from the end went into short term memory (recency effect).

Other compelling evidence to support this distinction between STM and LTM is the case of KF (Shallice & Warrington, 197) who had been in a motorcycle crash where he had sustained brain damage. His LTM seemed to be unaffected but he was only able to recall the last bit of information he had heard in his STM.


Critical Evaluation

Strengths

One strength of the multistore model is that is gives us a good understanding of the structure and process of the STM. This is good because this allows researchers to expand on this model. This means researchers can do experiments to improve on this model and make it more valid and they can prove what the stores actually do. Therefore, the model is influential as it has generated a lot of research into memory.

Many memory studies provide evidence to support the distinction between STM and LTM (in terms of encoding, duration and capacity).  The model can account for primacy & recency effects.

The model is supported by studies of amnesiacs: For example the HM case study.  HM is still alive but has marked problems in long-term memory after brain surgery. He has remembered little of personal (death of mother and father) or public events (Watergate, Vietnam War) that have occurred over the last 45 years. However his short-term memory remains intact.

Weaknesses

The model is oversimplified, in particular when it suggests that both short-term and long-term memory each operate in a single, uniform fashion.  We now know is this not the case.

It has now become apparent that both short-term and long-term memory are more complicated that previously thought.  For example, the Working Model of Memory proposed by Baddeley and Hitch (1974) showed that short term memory is more than just one simple unitary store and comprises different components (e.g. central executive, Visuospatial etc.).

In the case of long-term memory, it is unlikely that different kinds of knowledge, such as remembering how to play a computer game, the rules of subtraction and remembering what we did yesterday are all stored within a single, long-term memory store.  Indeed different types of long-term memory have been identified, namely episodic (memories of events), procedural (knowledge of how to do things) and semantic (general knowledge).

Rehearsal is considered a too simple explanation to account for the transfer of information from STM to LTM. For instance, the model ignores factors such as motivation, effect and strategy (e.g. mnemonics) which underpin learning.

Also, rehearsal is not essential to transfer information into LTM. For example, why are we able to recall information which we did not rehearse (e.g. swimming) yet unable to recall information which we have rehearsed (e.g. reading your notes while revising). Therefore, the role of rehearsal as a means of transferring from STM to LTM is much less important than Atkinson and Shiffrin (1968) claimed in their model.

The models main emphasis was on structure and tends to neglect the process elements of memory (e.g. it only focuses on attention and maintenance rehearsal). For example, elaboration rehearsal leads to recall of information than just maintenance rehearsal. Elaboration rehearsal involves a more meaningful analysis (e.g. images, thinking, associations etc.) of information and leads to better recall. For example, giving words a meaning or linking them with previous knowledge. These limitations are dealt with by the levels of processing model (Craik, & Lockhart, 1972).

Note: although rehearsal was initially described by Atkinson and Shiffrin as maintenance rehearsal (repition of information), Shiffrin later suggested that rehearsal could be elaborative (Raaijmakers, & Shiffrin, 2003).

The multi store model has been criticized for being a passive/one way/linear model.


References

Atkinson, R. C., & Shiffrin, R. M. (1968). Chapter: Human memory: A proposed system and its control processes. In Spence, K. W., & Spence, J. T. The psychology of learning and motivation (Volume 2). New York: Academic Press. pp. 89–195.

Baddeley, A .D., & Hitch, G. (1974). Working memory. In G.H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47–89). New York: Academic Press.

Craik, F. I. M., & Lockhart, R. S. (1972). Levels of processing: A framework for memory research. Journal of Verbal Learning and Verbal behavior, 11, 671-684.

Raaijmakers, J.G.W. & Shiffrin, R.M. (2003). Models versus descriptions: Real differences and langiage differences. Behavioral and Brain Sciences, 26, 753.


How to reference this article:

McLeod, S. A. (2007). Multi store model of memory. Retrieved from www.simplypsychology.org/multi-store.html


Was this article useful? Please help us improve by giving feedback below

Encoding is the way information is changed so that it can be stored in the memory. There are three main ways in which information can be encoded (changed):

    1. visual (picture),

    2. acoustic (sound),

    3. semantic (meaning).

Capacity concerns how much information can be stored.

Duration refers to the period of time information can last in the memory stores.

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