Memory - Multistore Model of Memory

Who proposed the Multi-store Model of Memory ?

Atkinson & Shiffrin (1968)

what are the key assumptions of the multistore model of memory ?

• the model is a linear model and describes how information flows through the memory system

• Suggests that memory is made up of 3 separate stores linked by processing

• The model describes the sensory register, short-term memory and long term memory

What are the three characteristics each store has ?

coding, capacity, duration

What is coding ?

the form in which the information is stored

What is capacity ?

how much information can be stored

What is duration ?

how long information can be stored for

How does the multi-store model work ?

1) information is gathered by the sensory organs enters the sensory register

2) Only the small amount of information that is paid attention to passes to short-term memory for further processing, the rest of the information is quickly lost

3) Information that is actively processed enough through rehearsal transfers to long term memory.

What is the sensory register ?

receives information from our senses from the environment

If information in the sensory register is paid attention to …

it is transferred to the short term memory store.

Information in the sensory register will decay if …

it is not paid attention to

What is the coding in the sensory register

modality specific

What does modality specific mean ?

information is stored in the form that it arrives and each of the five senses has its own sensory store

visual information will enter the …

iconic store

sound information enters the …

echoic store

What research supports coding in the sensory register ?

Crowder (1993)

What did crowder (1993) do ?

Found that the sensory register only holds info in the iconic store for a few milliseconds

but 2-3 seconds in the echoic store

This supports that the information is being coded in different stores.

What is the capacity of the sensory register ?

quite/very large

What research supports capacity of the sensory register ?

Sperling (1960)

What did sperling 1970 do ?

flashed a 3×4 grid of letters onto a screen for one-twentieth of a second and asked the participants to recall the letters in one row

Recall of the letters in the indicated row was high suggesting the info was already there - meaning the capacity is quite large.

What is the duration of the sensory register ?

about 0.5 - 3 seconds

What research supports the duration of the sensory register ?

Walsh & Thompson (1978)

What did Walsh & Thopson 1978 find ?

found the iconic sensory store has an average duration of 0.5 seconds which decreases as the person gets older

Suggests duration of sensory register is limited and dependent on age.

What is the STM ?

Short term memory

What does the STM do ?

temporarily stores information received from the SR (sensory register)

When rehearsal of the info in the STM occurs this is when the info will be moved to the …

LTM (long-term memory)

What is the coding in the STM ?

encoded Acoustically (according to how it sounds)

Why is info encoded acoustically in the STM ?

because when information is moved from the SR to the STM it has to be rehearsed which is generally done by verbalising the info either saying it out loud or repeating it to ourselves mentally.

What research supports acoustic coding in the STM ?

Baddeley (1966)

What did Baddeley (1996) do ?

he gave 4 groups of participants each a different list of words

1) acoustically similar

2) acoustically dissimilar

3) semantically similar

4) semantically dissimilar

Participants shown the words and asked to recall in the correct order immediately after hearing it (STM)

What did Baddeley find ?

Participants tended to do worse with acoustically similar words due to acoustic confusion

What is the capacity of the STM store ?

has a limited capacity score - between 5 and 9 items can be held but this can be increased by chunking.

What is chuncking ?

putting items together into meaningful groups.

For example the letters b c i v b t - then these could be chunked into bbc and itv - makes things easier to remember.

What is the research to support capacity of the STM ?

Miller (1956)

What did Miller 1956 do ?

used the immediate digit span test

participants were read a series of numbers and reported them back to the researcher

The amount of digits increased with each correct recall until they could no longer recall the digits correctly.

What did Miller find ?

the average digit span was 7+-2 (5 to 9)

What is the duration of the STM?

max of about 30 seconds

What is the research to support the duration of STM ?

Peterson & Peterson (1959)

What did Peterson & Peterson 1959 do ?

tested 24 undergraduates, each student took part in 8 trials

each student was given a trigram to remember and was also given a 3- digit number

The student was then asked to count backwards in threes from the 3 digit number until told to stop

This counting backwards prevents any rehearsal of the trigram

What did Peterson & Peterson find ?

around 90% of trigrams were recalled correctly after 3 seconds

but only 5 % after 18 second

What is long term memory ?

LTM involves storing information over lengthy periods of time, for even a whole lifetime

What is the coding of the LTM store ?

predominantly semantic so info is coded by meaning

What is the research to support the coding of the LTM store?

Baddeley (1966) the same study for the STM but with semantically similar words rather than acoustically similar

Baddeley found that after 20 mins memory for the words with similar meaning was poor suggesting that the LTM store must be coded semantically.

What is the capacity of the LTM store ?

potentially unlimited or a limit has never been found.

research to support the capacity of the LTM store -

Linton (1975)

what did Linton do ?

she conducted a study on her own LTM, over many years she kept a daily diary of events on cards giving each day a key word

What did Linton find ?

When she tried to recall what happened each day she could do so with 70% accuracy even up to 7 years later.

this shows a huge capacity of the long term memory.

What is the duration of LTM store ?

can last a lifetime. Many old people have detailed childhood memories even if the STM is not reliable.

If the information in the long term memory is not used it can …

decay over time.

What is the research to support duration of the LTM store ?

Bahrick (1975)

What did Bahrick do ?

tested 392 American uni grads, the grads were shown photographs from their high school yearbook and for each photograogh they were given a group of names and asked to select the name that matched

What did Bahrick find ?

90% of the participants were able to correctly match the names to a face 14 years after graduating and 60 % of the participants could correctly match the face and name 47 years after graduating

This shows some people were able to hold onto certain information like names for a lifetime.

Evaluation of the MSM (Multi-store model of memory)

What was the name of the case study that was left with extensive brain damage after contracting a viral infect

Clive Wearing

What is the case study of Clive Wearing about ?

Clive was still able to walk, talk and play music on the piano but lost the ability to form new long term memories.

Clive had a normal functioning …

STM

Why was it an issue that clive only hasd a normal function STM and not a normal functioning LTM ?

This was an issue because the short term memory can only hold info for up tot 30 seconds so therefore without being able to move info to the LTM anything that would happen to him he would forget.

What is the other case study related to the MSM?

KF - suffered brain damage resulting in difficulties dealing with verbal info in the STM but normal ability to deal with visual info

Supporting the idea that info is stored in different stores.