multi-store model of memory Flashcards
outline two assumptions of the multi-store model of memory
1- there are three, independent and distinct stores which are unitary
2- information is passed sequentially through this linear model and to do this, there are different modes of transference.
==> sensory - STM = attention
==> STM - LTM = rehearsal
what is the multi-store model of memory?
It is a cognitive model which gives a visual representation of memory
- STM and LTM are unitary
- flow of information sequentially through the linear model
what are the stores within the MSM?
- sensory memory
- short term memory
- long term memory
how does each store within the MSM differ?
- encoding
- capacity
- duration
define coding, capacity, and duration
coding - refers to the way incoming information is received and transformed into a form that can be stored in memory
capacity - refers to the amount of information that each store can hold
duration - refers to the length of time information can be held in a store before it is forgotten
what does it mean when the stores are described as independent, distinct, and unitary?
unitary - there is only one type of each store
independent - they function alone which means if one store was damaged, it wouldn’t effect the functionality of the others
distinct - each store has their differences in the way in which they encode, their duration, and their capacity
how does the MSM suggest we encode in sensory memory?
through all five senses
==> consists of sensory modality which means it is specific to the sense receiving information. For example, acoustic store for sounds, iconic (visual) for pictures etc.
what does the MSM suggest the duration of sensory memory is?
limited - very short
==> only long enough for stimuli to be recognised and then it is lost or passed through to STM if pay attention
what does the MSM suggest the capacity of sensory memory is?
infinite
==> all information in surrounding and periphery is entering sensory register - sounds, light, scents etc
how does the MSM suggest we encode in short term memory?
acoustically
==> Baddelely (1966) supports this
what does the MSM suggest the duration of short term memory is?
18-30 seconds
==> Peterson and Peterson (1959) supports this
However, it was found that maintenance rehearsal improves this number
what does the MSM suggest the capacity of short term memory?
5-9 items and Miller (1956) coined the phrase 7 +/- 2 items
==> jacobs (1887) supports this
However, if items are chunked together for example, grouping together items so they are processed as single items so capacity is considerably increased
how does the MSM suggest we encode in long term memory?
semantically
==> Baddeley (1966) supports this
what does the MSM suggest the duration of long term memory is?
infinite / lasts a lifetime
==> Bahrick et al. (1975) supports
what does the MSM suggest the capacity of long term memory is?
unlimited
- no research to date has proved otherwise
how does information enter short term memory from sensory memory
paying attention
==> Peterson and Peterson supports this
how does information enter long term memory from short term?
rehearsal
how is information forgotten in sensory memory?
not paying attention
how is information forgotten in short term memory?
decay or displacement
how is information forgotten in long term memory?
failure to retrieve information from short term memory
lack of consolidation from STM
==> HM hippocampus damage supports this
what did Jacob’s research into?
the capacity of short term memory
what technique did Jacob’s devise and why?
the serial digit span technique
- this is so an accurate measure of STM can be obtained
what is the procedure of Jacob’s (1887) study?
- lab experiment using his digit span technique
- participants presented with a sequence of letters or digits followed by serial recall
- the pace of each item presented was controlled using a metronome to half second intervals
- the sequence began at three items and it increased by one item at a time until they failed to recall correctly
- this was then repeated to establish their digit or letter span
- the researcher decided the STM span was the longest sequence they were able to recall accurately on at least half of the trials that were conducted
what were the findings go Jacobs (1887) study?
the average STM span was between 5-9 terms
==> digits recalled better at 9.3 items
==> letters recalled worse at 7.3 item
found that STM span increased with age
==> one sample found 6.6 average for 8 y/o compared to 8.6 average for 19 y/o
what did Jacobs (1887) conclude?
-STM is a limited storage store with a capacity of 5-9 items
- capacity isn’t determined by the nature of the information so to be stored, it doesn’t require semantics
- capacity is determined by the size of items
- STM span increased with age which may be due to increasing brain capacity or improved memory techniques like chunking
Evaluate Jacobs’ (1887) study
Strength: using digit span technique
- scientific methodology so objective measures
- therefore, the findings can be generalised
Strength: high temporal validity
- easily replicable study which does transgress over time
(original study from 1887 and still applicable)
Limitation: lab experiment so controlled environment cause low mundane realism / ecological validity
- letters and digits recall aren’t realistic to every day tasks so poses a question of whether they are generalisable as the results may not be a true representation
what did Peterson and Peterson (1959) research into?
the duration of short term memory
what technique did Peterson and Peterson (1959) devise?
Brown Peterson technique
what was the aim of Peterson and Peterson (1959)
to show that information is only held in STM for about 20 seconds, after that it disappears if no rehearsal
what was the procedure of Peterson and Peterson (1959)?
- lab experiment
- participant’s presented with sets of trigrams which are random constants in sets of threes
- they then recalled them in serial order after an increasing delay of 3 seconds up to 18 seconds
- during this delay, they were presented with an interference task of counting backwards in threes from a three digit number preventing rehearsal
- the trigram had to be recalled with 100% accuracy to be considered correct
what were the findings of Peterson and Peterson (1959)
the longer the interval between trigram and recalling the trigram, the less accurate the recall
- 3 seconds = 80%
- 6 seconds = 50%
- 9 seconds = 30%
- 12 seconds = 25%
- 15 seconds = 15%
- 18 seconds = 10%
what did Peterson and Peterson (1959) conclude?
if rehearsal is prevented as shown by using an interference task, information rapidly vanishes from STM
what did Baddeley (1966) investigate?
how we encode within STM and LTM
what is the procedure of Baddeley (1966)
A lab experiment using four types of word lists testing four different conditions
1. acoustically similar
2. acoustically dissimilar (control)
3. semantically similar
4. semantically dissimilar (control)
the participants had to recall the words within each group in the same order either immediately to test STM or after a delay for LTM
what were the findings of Baddeley (1966)?
STM:
- acoustically similar words had the worst recall
- no difference in semantically similar and dissimilar word recall
LTM:
- semantically similar words had the worst recall and getting them in the correct order was incredibly difficult as they all meant the same thing
- there was no difference for acoustically similar / dissimilar words
what did Baddeley (1966) conclude?
STM relied on acoustic coding to process information
LTM relied on semantic coding to process information
Evaluate Baddeley (1966) study
strength: lab experiment
- means highly controlled so the extraneous variables are taken care of and do not interfere with study
strength: standardised procedure
- objective measure so reliable findings obtained
limitation: highly controlled environment
- lacks ecological validity as tasks aren’t representative to every day tasks so questions whether results can be generalised
limitation: words used
- the words used have little to no meaning so were harder to recall and in reality the information we have to recall have more meaning and significance which would make recall easier
what could be improved in Baddeley’s (1966) study to improve accuracy or findings?
using a stop watch to ensure that the same amount of time is given to each condition, increasing validity of results
what part of life do people generally find unable to recall and what is it called?
early childhood - cannot recall episodes of their life before the age of typically 2
==> this is known as childhood or infantile amnesia
what did Bahrick (1975) investigate?
the duration of very long term memory - VLTM
- wanted to show that memories could last over several decades in order to support the assumption that the duration of LTM is lifelong
what is the procedure of Bahrick’s (1975) study
- an opportunity sample of 392 American ex-high-school students was formed
- there were four different conditions which were used:
- free recall of the names of as many
- photo recognition test - identify in a set of 50, only some who were classmates
- name recognition
- name and photo matching
the time since the participants left high school was in a range up to 47 years and therefore testing VLTM
- results were compared to yearbooks containing photos and names of all the students
what were the findings of Bahrick et al. (1975) study
face and name recognition:
after 48 years, face recognition was accurate for 80% and name recognition was accurate for 40%
Free recall:
(considerably less accurate)
after 15 years it was 60% accurate and after 48 years it was 30% accurate
SUMMARY:
- free recall of name recognition had the worst recall as there were no cues given
- name and photo match had the best recall as there were the most cues given
what did Bahrick et al (1975) conclude
Suggests that LTM does last a lifetime as such strong recall after 47 years therefore unlikely for it to fade too much further
- rarely forgotten once recognition cues have been given
support the claim that recognition is better than recall
evaluate Bahrick (1975) study
Strength: high ecological validity
-the procedure is related to real life ==> looking at old photographs and recalling names is typically done irl
Limitation: opportunity sample
- some people may have had better recall as they were still in the same area or still in contact with people in the yearbook
- others may have had worse recall as they never really knew the names of people due to them being less social
limitation: VLTM for one particular type of memory
- cannot be concluded that VLTM exists for all types of LTM as only one of the three types has been tested
- can these results be generalised?? no
Limitation: why has recall become worse over time/
- study doesn’t explain why this is, whether this is a side effect of old age or is there some limit to duration which impacts the memories as we get older and continue to make more memories??
what is an opportunity sample?
- what’s a strength and limitation of using this
an opportunity sample includes individuals that are readily available at the time of the study
==> strength - can get the sample quickly
==> limitation - may end up with a non-representative sample
who is patient H.M. investigated by (Milner et al. 1978) and what happened to him?
A man who suffered from epilepsy which led to doctors to remove part of his temporal lobe containing his hippocampus. His seizures significantly reduced but this caused him to become an anterograde amnesiac
what were the outcomes of patient H.M’s surgery? (Milner et al 1978)
HM’s short term memory store remained the same but he couldn’t transfer it to LTM, retrieve it and seemed incapable of remembering any new fact or event
Declarative memory was severely damaged (memory of specific facts and events)
Procedural memory was unaffected (learning new skills)
how does HM case study support MSM?
Proves there is an existence of two separate stores which are independent and distinct
- STM was impaired but had no effect on the functionality of LTM
who is the main case study for the multi-store model of memory?
Clive Wearing (Wilson, 1985)
- also supporting evidence for patient H.M
who is Clive Wearing and what illness does he suffer from?
Clive suffers from anterograde amnesia which means that he cannot create new memories as well as retrograde amnesia meaning he’s lost many of his memories.
==> this was brought about from a herpes virus which attacked his hippocampus and caused this amnesia to develop
What is Clive Wearing’s memory like?
- unable to transfer information from his STM to LTM which explains why it feels as though he is ‘waking up’ constantly throughout the day.
- can store information for about 7-30 seconds before it is displaced
==> eg he always greets his wife with vigour because he genuinely believes he hasn’t seen her in years even if she left but a moment ago - he can however remember how to play piano perfectly but if you asked him if he could play the piano he would answer no as he cannot remember the act of learning to play
==> evidence for types of LTM (procedural memory was not affected but his declarative memory is)
Evaluate Clive Wearing AND patient HM case study (GRAVE) ==> the same points can be made as both a case study
Generalisability: not generalisable at all as it is a case study meaning it only affected him and data was only collected surrounding him. Whilst there may be similar case studies, the chances of the exact same events occurring in the wider population are very unlikely
Reliability: not reliable as the study cannot be repeated
==> cannot give someone brain damage for the sake of an experiment
Application: can be applied as evidence for the MSM model
Validity: incredibly valid as we get rich information from this study, allowing us to explore in depth about Wearing’s situation
Ethics: N/A
