1. Memory + The Multi-Store Model of Memory Flashcards
What are the two main types of memory?
Short term memory and long term memory
What is short term memory?
Your memory for immediate events.
It temporarily stores information revived from the sensory register.
What is long term memory?
Your memory for events that have happened in the more distant past and are enduring.
What is coding?
Coding refers to the format in which information is stored in the various memory stores. Information enters the brain via the senses (e.g. Eyes and ears) and then is changed to another form so that it can be stored in the memory. Info can be stored acoustically, visually or semantically.
What is capacity?
Capacity refers to the amount of information that can be held in memory.
What is duration?
Duration refers to the length of time that information can be held in memory.
What is the multi-store model of memory?
The MSM is a linear model which represents the flow of information through the memory system. It proposed that memory is made up of three separate memory stored linked together by processes that enable information to transfer from one store to the next. Each store has a different purpose and each differs in terms of coding, capacity and duration.
What three stores is the multi-store model of memory made up of?
- Sensory register
- Short term memory
- Long term memory
What is the sensory register?
The sensory register temporarily stores information from our senses. It is constantly receiving information and is held in a raw ‘unprocessed’ form with separate stores for each of the 5 senses. The two main stores are iconic (visual information is first encoded visually) and echoic (sound based info is first encoded acoustically).
How is information coded in the sensory register?
Information is coded depending on the sense that is picked up - e.g. Visual, auditory or tactile
What is the capacity of the sensory register?
The sensory register has a huge capacity
What is the duration of the sensory register?
The sensory register has a very limited duration of <0.5 - 2 seconds.
What study provides evidence for the capacity of the sensory register?
Sperling
3x4 grid of letters - have to recall one row
Describe Sperling’s study and what it provides evidence for
Sperling conducted a lab experiment in which a 3x4 grid of letters was projected for 50 milliseconds, and participants were asked to recall letters of one row (indicated by a high, medium or low tone). Recall of the indicated row was high (typically 3 out of 4) which suggests that all informs was originally there, indicating the capacity of the SR is quite large.
How does information pass from the sensory register to short term memory?
You have to pay attention to the information in the sensory register for it to pass on to STM. If information is not attended to it disappears quickly through spontaneous decay.
What is the key process in STM and why?
The key process is maintenance rehearsal (verbal repetition of information) as it allows us to keep info in STM long enough to use it. Also, if we rehearse information for long enough it will eventually pass into our LTM.
The more information is rehearsed, the longer it will remain in LTM.
How is information coded in short term memory?
Acoustically
What study provides evidence for how information is coded in STM?
Baddeley
Recall of acoustically similar/ dissimilar + semantically similar/dissimilar words either immediately or after 20 mins.
Describe Baddeley’s study
Lab experiment where participants were given acoustically similar/dissimilar
or semantically similar/dissimilar words to learn. Participants were asked to recall words in the order they were first given either immediately (to test STM) or after a 30
Minute delay (to test LTM).
Immediate recall was worse with acoustically similar words, and delayed recall was worse with semantically similar words. This suggests that information is largely encoded acoustically in STM and semantically in LTM.
Evaluate Baddeley’s study
✅
• Lab study - high degree of control over extraneous variables
• Made sure they were all familiar words, to prevent word familiarity becoming a confounding variable - could therefore establish cause and effect
❌
The words used had no personal meaning to the participants. When processing more meaningful information, people may use semantic coding even for STM tasks. This means the results of this study have limited application so we may not be able to generalise the findings.
What is the capacity of short term memory?
7 +/- 2 items or 5-9 items
What study provides evidence for the capacity of STM?
Miller
Chunking - 7 +/- 2 items
Describe Miller’s study
Miller used experimental findings from several different experiments to support his idea that on average, STM can hold 7 plus or minus 2 chunks or bits of information. He stated this can be increased by chunking.
What is the duration of short term memory?
18 - 30 seconds
What study provides evidence for the duration of short term memory?
Peterson and Peterson
Trigrams + counting backwards in 3’s
Describe Peterson and Peterson’s study
Lab experiment where participants were given trigrams which they had to recall after varying amounts of time from 0-18 seconds. On presentation of each trigram, they were required to verbally count backwards in threes to prevent participants rehearsing the trigrams.
Participants recalled (on average) about 80% of trigrams correctly with a 3 second interval. Average recall after 18 seconds fell to 3%. Suggesting that the duration of STM is approximately 18-30 seconds if rehearsal is prevented.
The results of the study also show how STM is different from LTM in terms of duration and thus can be used to support the functional separation of STM and LTM.
Evaluate Peterson and Peterson’s study
❌
Limitation = artificial stimulus
Trying to memorise trigrams does not reflect real-life memory activities where what we try to remember is meaningful. So it could be argued that this study lacks external validity.
✅
However, we do sometimes try to remember fairly meaningless things like phone numbers - so the study is not totally irrelevant.
Evaluate Miller’s study
✅
Has many practical applications such as the postcode system. This shows how research into the capacity of STM has helped improve efficiency of memory in a real life situation
❌
Limitation is that he may have overestimated the capacity of STM. More recently, Cowan et al reviewed other research and concluded that the capacity of STM was only about 4 items. This suggests that the lower end of Miller’s estimate (5 items) is more appropriate than 7.
How is long term memory coded?
Semantically (by meaning)
What study provides evidence for the coding of long term memory?
Baddeley
Acoustically similar/dissimilar + semantically similar/dissimilar words.
Worse recall of semantically similar words after 20 min delay suggests LTM is coded semantically.
What is the capacity of long term memory?
The potential capacity of long term memory is unlimited.
What is the duration of long term memory?
The duration of long term memory is potentially unlimited
What study provides evidence for the duration of long term memory?
Bahrick et al.
Yearbook - memories of other students.
Describe Bahrick et al.’s study
Field experiment to explore the length of time memories can be retained. They tested the memory of 392 American graduates participants aged between 17 and 74 for their former classmates using their yearbooks. Participants who were tested working 15 years of graduation were about 90% accurate in photo recognition, suggesting that LTM can last a very long time. Participants tested 48 years after graduation were about 70% accurate.
Evaluate Bahrick et al.’s study
✅
High external validity - field experiment where real-life meaningful memories were studied so the behaviour shown was more valid and authentic
❌
Real-life research = lack of control over confounding variables, such as the fact that the participants may have looked at their yearbook photos and rehearsed their memories over the years.
EVALUATION OF THE MSM
Give a strength of the MSM
The MSM is supported by research showing that STM and LTM are separate stores with different functions. Murdock’ serial positions curve provides further support for the existence of two separate stores.
Lab experiment - participants presented with lists of words that vary in length from 10 up to 40, presented at 2 second intervals to be recalled in any order.
More words were recalled from the beginning of the list (the primacy effect) and the end of the list (the recency effect). There was poor recall of words in the middle of the list.
The primary and recency effects are taken as strong evidence for the existence of two separate memory stores with different functions.
EVALUATION OF THE MSM
Describe the primacy and recency effect in Murdock’s serial curve and how they support the MSM
The primacy effect represents recall from LTM as the first words have been rehearsed into LTM.
The recency effect represents recall from STM as the last few words were the last to enter STM and it hadn’t been 18 seconds since they heard it.
The primary and recency effect are taken as strong evidence for the existence of two separate memory stores with different functions.
EVALUATION OF THE MSM
Evaluate how the MSM can be seen as oversimplified in terms of STM
A limitation is that evidence suggests there is more than one type of STM.
Shallice and Warrington studies KF, a patient with amnesia. His STM for verbal information was very poor (couldn’t recall digits which were read aloud to him) but was more or less normal for visual materials (recall was better when he could read the digits himself)
Findings such as this suggests there must be at least one STM to process visual information and one for verbal. This is a weakness of the model as it challenger the concept of a single unitary STM.
EVALUATION OF THE MSM
Evaluate how the MSM can be seen as oversimplified in terms of LTM
A limitation of the MSM is that it oversimplifies LTM.
There is a lot of research evidence that LTM is not a unitary store.
EVALUATION OF THE MSM
Evaluate the MSM’s type of rehearsal
A limitation of the MSM is that it only explains one type of rehearsal; maintenance rehearsal. It’s claim that maintenance rehearsal (verbal repetition of information) is essential for transferring info into LTM has been disputed.
Craik and Watkins claim there are two types of rehearsal - maintenance and elaborative. They claim that maintenance rehearsal simply keeps info in the STM and that elaborative rehearsal is needed for long term storage. Elaborative rehearsal is where info is linked to existing knowledge or you consider its meaning.
This is a very serious limitation of the MSM because it is a research finding that cannot be explained by the model.
EVALUATION OF THE MSM
Evaluate the MSM’s use of artificial materials
A limitation is that the research studies supporting the MSM use artificial materials. The MSM is supported by highly controlled artificial lab experiments where patients are asked to recall letters, digits etc. which may undermine the validity of the model. In real life we form memories related to useful things such as names, facts, places etc.
This suggests the MSM lacks external validity. Research findings may reflect how memory works with meaningless material in lab testing, but does not reflect how memory mainly works in everyday life.
EVALUATION OF THE MSM
Evaluate the MSM’s oversimplification of LTM
A limitation of the MSM is that it oversimplifies LTM. There is a lot of research that suggests LTM is not a unitary store.
We have one LTM for memories about the world (semantic), and a different one for memories of how to ride a bike (episodic).
The MSM is limited because it does not reflect these different types of LTM.
