Short + Long Term Memory Capacity Duration Coding
Capacity – how much can be held in memory
STM 7+/-2 18-30 Acoustically
Coding – How information is changed so it can be stored seconds
LTM Potentially Potentially Semantically
Duration – How long a memory lasts before being forgotten unlimited unlimited
Long term memory – your memory for events that have happened in the past
Short term memory – you memory for immediate events
Evaluation of STM Capacity Evaluation of Coding
P – weakness, capacity of STM may be even more limited P – weakness, STM may not be exclusively acoustic
E – Cowan (2001) concluded STM is limited to about 4 E – STM generally relies on acoustic coding for storing
chunks suggesting information, but experiments have shown visual codes are also
used.
E – research on capacity of STM for visual information
found that 4 items was about the limit E – for example a study found that ppts used visual coding in STM
if they were given pictures and prevented from doing verbal
L – meaning the lower end of Miller’s range is more rehearsal in retention interval before performing visual recall
appropriate (7-2 which is 5) task
P – weakness, capacity of STM is not the same for L –STM should not be assigned one specific coding type
everybody
P – weakness, Baddeley may not have tested LTM
E – Jacobs also found that recall increased steadily with
age E – in the study by Baddeley STM was tested by asking ppts to
recall a word list immediately after hearing it.
E – this increase could be due to gradual increased brain
capacity and/or development of strategies to improve E – LTM was tested by waiting 20 minutes it is questionable as to
digit span whether this is really testing the LTM
L – therefore millers range cannot be generalised to all L – so the results may not be reliable as they may not have been
ages so it’s not valid. testing a realistic LTM memory
Evaluation of STM and LTM Duration
P – weakness, testing of STM was artificial
E – trying to memorise consonant syllables does not reflect most everyday memory activities and is not meaningful
E – however we do sometimes try to remember fairly meaningless things such as groups of numbers (e.g. post
codes)
L – therefore this study has low ecological validity
P – weakness, STM results may be due to displacement
E – in Petersons’ study ppts were counting numbers in their STM and this may displace the syllables to be
remembered.
E – Reitman used auditory tones instead of numbers so that displacement wouldn’t occur + found duration of STM
was longer
L – this suggests that forgetting in Petersons’ study was due to displacement rather than decay, and was not
measuring duration of STM
, Multi Store Model of Memory
Sensory register
Information collected by your ears, eyes, nose, fingers etc.
Duration – less than half a second
Capacity – very large
Coding – sense specific
Attention
Transfers information from sensory stores to the short term memory
Short term memory
Can be used for immediate tasks
Duration – 0-18 seconds
Capacity – 7+/-2
Encoding mainly auditory HM: brain damage caused by operation to
remove hippocampus from both sides of his
Maintenance Rehearsal
brain to reduce his severe epilepsy. His
Repetition keeps information in STM intellect and personality remained but he
Will eventually create a LTM could not form new LTMs.
Long term memory
Duration – unlimited
Capacity – unlimited
Encoding – mainly semantic
Retrieval
Process of getting information from LTM involving information passing back through STM
P – weakness, over simplified. – suggests STM and LTM operate in a single unitary forms.
E – research has shown that the LTM and the STM are more complex
E – eg; in the working model of memory showed short term memory comprises of different components (central executive etc.)
L – so the multi store model of memory provided a good starting point for other psychologists to work on but by itself is too simple
P – strength, supporting evidence – supporting the existence of a separate STM and LTM which is the basis of the MSM
E – controlled lab studies on capacity, duration and coding support the existence on separate store
E – studies using brain scanning techniques have also demonstrated a difference between STM and LTM as well as case studies
L – therefore the idea from the MSM that the stores are separate is proven to be true
P – weakness, LTMs require more than just maintenance rehearsal
E – Craik and Lockhart suggested LTM memoires are created by the processing you do rather than through maintenance rehearsal
E – conducted experiment showing things that are processed more deeply are more memorable (deep vs shallow processing)
L – This shows that this ‘deep’ or elaborative processing is a key process in creating long term memories.
Capacity – how much can be held in memory
STM 7+/-2 18-30 Acoustically
Coding – How information is changed so it can be stored seconds
LTM Potentially Potentially Semantically
Duration – How long a memory lasts before being forgotten unlimited unlimited
Long term memory – your memory for events that have happened in the past
Short term memory – you memory for immediate events
Evaluation of STM Capacity Evaluation of Coding
P – weakness, capacity of STM may be even more limited P – weakness, STM may not be exclusively acoustic
E – Cowan (2001) concluded STM is limited to about 4 E – STM generally relies on acoustic coding for storing
chunks suggesting information, but experiments have shown visual codes are also
used.
E – research on capacity of STM for visual information
found that 4 items was about the limit E – for example a study found that ppts used visual coding in STM
if they were given pictures and prevented from doing verbal
L – meaning the lower end of Miller’s range is more rehearsal in retention interval before performing visual recall
appropriate (7-2 which is 5) task
P – weakness, capacity of STM is not the same for L –STM should not be assigned one specific coding type
everybody
P – weakness, Baddeley may not have tested LTM
E – Jacobs also found that recall increased steadily with
age E – in the study by Baddeley STM was tested by asking ppts to
recall a word list immediately after hearing it.
E – this increase could be due to gradual increased brain
capacity and/or development of strategies to improve E – LTM was tested by waiting 20 minutes it is questionable as to
digit span whether this is really testing the LTM
L – therefore millers range cannot be generalised to all L – so the results may not be reliable as they may not have been
ages so it’s not valid. testing a realistic LTM memory
Evaluation of STM and LTM Duration
P – weakness, testing of STM was artificial
E – trying to memorise consonant syllables does not reflect most everyday memory activities and is not meaningful
E – however we do sometimes try to remember fairly meaningless things such as groups of numbers (e.g. post
codes)
L – therefore this study has low ecological validity
P – weakness, STM results may be due to displacement
E – in Petersons’ study ppts were counting numbers in their STM and this may displace the syllables to be
remembered.
E – Reitman used auditory tones instead of numbers so that displacement wouldn’t occur + found duration of STM
was longer
L – this suggests that forgetting in Petersons’ study was due to displacement rather than decay, and was not
measuring duration of STM
, Multi Store Model of Memory
Sensory register
Information collected by your ears, eyes, nose, fingers etc.
Duration – less than half a second
Capacity – very large
Coding – sense specific
Attention
Transfers information from sensory stores to the short term memory
Short term memory
Can be used for immediate tasks
Duration – 0-18 seconds
Capacity – 7+/-2
Encoding mainly auditory HM: brain damage caused by operation to
remove hippocampus from both sides of his
Maintenance Rehearsal
brain to reduce his severe epilepsy. His
Repetition keeps information in STM intellect and personality remained but he
Will eventually create a LTM could not form new LTMs.
Long term memory
Duration – unlimited
Capacity – unlimited
Encoding – mainly semantic
Retrieval
Process of getting information from LTM involving information passing back through STM
P – weakness, over simplified. – suggests STM and LTM operate in a single unitary forms.
E – research has shown that the LTM and the STM are more complex
E – eg; in the working model of memory showed short term memory comprises of different components (central executive etc.)
L – so the multi store model of memory provided a good starting point for other psychologists to work on but by itself is too simple
P – strength, supporting evidence – supporting the existence of a separate STM and LTM which is the basis of the MSM
E – controlled lab studies on capacity, duration and coding support the existence on separate store
E – studies using brain scanning techniques have also demonstrated a difference between STM and LTM as well as case studies
L – therefore the idea from the MSM that the stores are separate is proven to be true
P – weakness, LTMs require more than just maintenance rehearsal
E – Craik and Lockhart suggested LTM memoires are created by the processing you do rather than through maintenance rehearsal
E – conducted experiment showing things that are processed more deeply are more memorable (deep vs shallow processing)
L – This shows that this ‘deep’ or elaborative processing is a key process in creating long term memories.
