1. Coding, capacity and duration of memory
AO1:
- Short term memory (STM): the limited capacity memory store. Mainly acoustic, holds
around 7 ± 2 items, lasts around 18 seconds.
- Long term memory (LTM): permanent memory store. Semantic (meaning), unlimited
capacity and duration.
- Coding: format in which information is stored in various memory stores.
- Baddley gave 4 groups of participants words to remember that were acoustically
similar, acoustically dissimilar, semantically similar and semantically dissimilar.
Findings found that STM did worse on acoustically similar words and LTM did worse
on semantically similar words. Showing that info is coded acoustically with STM and
semantically with LTM.
- Capacity: amount of information held in a memory store.
- Digit span - Jacobs: repeating numbers read by researchers in an increasing number
until they got one wrong. Indicates an individual's digit span; digits held around 9.3
items, letters was 7.3. Miller - chunking into units, generally 7 ± 2 items.
- Duration: length of time information can be held.
- STM: Peterson and Peterson gave students 3 digit numbers and consonant syllables
to remember (e.g. YCG). Counted backwards until told not to to avoid rehearsal.
Were then told to stop after 3 second (retention) intervals until 18. After 3 seconds,
recall was 80%, and became 3% by 18 secs. Average STM duration is 18 seconds
without rehearsal.
- LTM: Bahrick et al studied ppts from 17-74 using high school textbooks. Tasks
included photo-recognition test and free recall test to recall name of graduating class.
Findings found that 15years of graduation photo recognition was 90% accurate. After
48 years it fell to 70%. Free recall was less accurate; 60% after 15 years and 30%
after 48 years. Shows LTM can last up to a lifetime.
AO3:
Coding:
- STRENGTH: P: Baddley’s study separate memory stores. E: the idea that STM uses
acoustic coding and LTM uses semantic encoding. E: important as it led to the MSM.
- LIMITATION: P: study uses artificial stimuli. E: words had no meaning to ppts, study
does not tell us about the type of coding in different situations (irl). Processing
meaningful info may mean semantic coding for STM. E: limited application.
Capacity:
- STRENGTH: P: valid study, replicable. E: old study that may have lacked adequate
controls, ppts digit span may have been estimated wrong due to confounding
variables, but the findings have been replicated and confirmed in more controlled
studies such as Bopp and Verhaeghen. E: Jacobs is a valid test of capacity in STM.
- LIMITATION: P: Miller may have overestimated digit span. E: Cowan reviewed other
research and found that capacity may be 4 ± 1 items. E: shows that 5 items may be
more accurate than 7 items.
Duration:
- STRENGTH: P: Bahrick et al had high validity. E: investigation of meaningful
memories; when studies on LTM used meaningless pictures, recall rate was less
(Shepard). E: more real ‘estimate’ of LTM.
, - LIMITATION: P: P&P used stimulus material that was artificial. E: not irrelevant study
as we have to remember meaningless info such as phone numbers, but memorising
consonant syllables do not reflect daily memory. E: study lacks external validity.
2. Multi-store model of memory
AO1:
- MSM: made up of three stores; STM, LTM stores and sensory register store. Info is
passed in a linear way despite the stores being separate. If one store is damaged,
the others will work well. Also differ in coding, duration and capacity.
- Sensory register: memory stores for 5 senses; vision (iconic), hearing (echoic),
physical touch (haptic). Info only passes further in the system if it is paid attention to.
Capacity is large with millions of receptors but info only lasts for less than half a
second. Unprocessed info from environmental stimuli.
- Short term memory store: next in model, receives info that has been paid attention to,
18 seconds duration, limited capacity (Jacobs and Miller) and info will start to decay if
not rehearsed. Info will also disappear if new info comes through; displacement.
Rehearsed info will pass through to LTM. Info is coded acoustically here.
- Long term memory store: final storage system, permanent memory store for
rehearsed information. Recalled info goes back to the STM through retrieval, as none
of our memories come directly from LTM according to MSM. Codes info semantically.
AO3:
STRENGTHS: P: evidence from case studies. E: patient HM, bike crash that led to
removal of hippocampus. Personality and intellect was the same, LTM was affected.
E: supports the idea of separate stores. CP: unique case study, cannot be
generalised to population.
- P: research support. E: Baddley found that mixing up words that sound similar come
from STM, but mixing words that mean similar come from LTM. other studies. E:
support claims of the MSM that STM and LTM stores are different.
- CP: P: lack of mundane realism. E: studies that support the MSM use contrived
materials with meaningless numbers, letters etc. E: may not be a valid model of
memory in everyday lives compared to more meaningful information.
LIMITATIONS: P: evidence of multiple STM stores. E: Shallice and Warrington had a
patient KF that had amnesia. STM for digits was lower when read to him compared to
reading and recalling them himself. E: MSM may be wrong in claiming there is only
one type of STM store, and may be different types of processing information.
- P: prolonged rehearsal may not be needed for LTM. E: MSM says the more you
rehearse info, the more likely it is to transfer to LTM. Craik and Watkins said the type
of rehearsal is more important than the amount. Linking info to existing knowledge
increases likelihood of transfer, even without prolonged rehearsal. E: MSM does not
fully explain how long term storage occurs.
3. Types of long-term memory
AO1:
- Tulving thought the MSM’s view of LTM was too simplistic, so came up with the:
- Episodic memory: LTM store for personal events. Memories of events occurred with
people, places and behaviours involved. Memories have to be consciously retrieved
with effort. Time stamped.
AO1:
- Short term memory (STM): the limited capacity memory store. Mainly acoustic, holds
around 7 ± 2 items, lasts around 18 seconds.
- Long term memory (LTM): permanent memory store. Semantic (meaning), unlimited
capacity and duration.
- Coding: format in which information is stored in various memory stores.
- Baddley gave 4 groups of participants words to remember that were acoustically
similar, acoustically dissimilar, semantically similar and semantically dissimilar.
Findings found that STM did worse on acoustically similar words and LTM did worse
on semantically similar words. Showing that info is coded acoustically with STM and
semantically with LTM.
- Capacity: amount of information held in a memory store.
- Digit span - Jacobs: repeating numbers read by researchers in an increasing number
until they got one wrong. Indicates an individual's digit span; digits held around 9.3
items, letters was 7.3. Miller - chunking into units, generally 7 ± 2 items.
- Duration: length of time information can be held.
- STM: Peterson and Peterson gave students 3 digit numbers and consonant syllables
to remember (e.g. YCG). Counted backwards until told not to to avoid rehearsal.
Were then told to stop after 3 second (retention) intervals until 18. After 3 seconds,
recall was 80%, and became 3% by 18 secs. Average STM duration is 18 seconds
without rehearsal.
- LTM: Bahrick et al studied ppts from 17-74 using high school textbooks. Tasks
included photo-recognition test and free recall test to recall name of graduating class.
Findings found that 15years of graduation photo recognition was 90% accurate. After
48 years it fell to 70%. Free recall was less accurate; 60% after 15 years and 30%
after 48 years. Shows LTM can last up to a lifetime.
AO3:
Coding:
- STRENGTH: P: Baddley’s study separate memory stores. E: the idea that STM uses
acoustic coding and LTM uses semantic encoding. E: important as it led to the MSM.
- LIMITATION: P: study uses artificial stimuli. E: words had no meaning to ppts, study
does not tell us about the type of coding in different situations (irl). Processing
meaningful info may mean semantic coding for STM. E: limited application.
Capacity:
- STRENGTH: P: valid study, replicable. E: old study that may have lacked adequate
controls, ppts digit span may have been estimated wrong due to confounding
variables, but the findings have been replicated and confirmed in more controlled
studies such as Bopp and Verhaeghen. E: Jacobs is a valid test of capacity in STM.
- LIMITATION: P: Miller may have overestimated digit span. E: Cowan reviewed other
research and found that capacity may be 4 ± 1 items. E: shows that 5 items may be
more accurate than 7 items.
Duration:
- STRENGTH: P: Bahrick et al had high validity. E: investigation of meaningful
memories; when studies on LTM used meaningless pictures, recall rate was less
(Shepard). E: more real ‘estimate’ of LTM.
, - LIMITATION: P: P&P used stimulus material that was artificial. E: not irrelevant study
as we have to remember meaningless info such as phone numbers, but memorising
consonant syllables do not reflect daily memory. E: study lacks external validity.
2. Multi-store model of memory
AO1:
- MSM: made up of three stores; STM, LTM stores and sensory register store. Info is
passed in a linear way despite the stores being separate. If one store is damaged,
the others will work well. Also differ in coding, duration and capacity.
- Sensory register: memory stores for 5 senses; vision (iconic), hearing (echoic),
physical touch (haptic). Info only passes further in the system if it is paid attention to.
Capacity is large with millions of receptors but info only lasts for less than half a
second. Unprocessed info from environmental stimuli.
- Short term memory store: next in model, receives info that has been paid attention to,
18 seconds duration, limited capacity (Jacobs and Miller) and info will start to decay if
not rehearsed. Info will also disappear if new info comes through; displacement.
Rehearsed info will pass through to LTM. Info is coded acoustically here.
- Long term memory store: final storage system, permanent memory store for
rehearsed information. Recalled info goes back to the STM through retrieval, as none
of our memories come directly from LTM according to MSM. Codes info semantically.
AO3:
STRENGTHS: P: evidence from case studies. E: patient HM, bike crash that led to
removal of hippocampus. Personality and intellect was the same, LTM was affected.
E: supports the idea of separate stores. CP: unique case study, cannot be
generalised to population.
- P: research support. E: Baddley found that mixing up words that sound similar come
from STM, but mixing words that mean similar come from LTM. other studies. E:
support claims of the MSM that STM and LTM stores are different.
- CP: P: lack of mundane realism. E: studies that support the MSM use contrived
materials with meaningless numbers, letters etc. E: may not be a valid model of
memory in everyday lives compared to more meaningful information.
LIMITATIONS: P: evidence of multiple STM stores. E: Shallice and Warrington had a
patient KF that had amnesia. STM for digits was lower when read to him compared to
reading and recalling them himself. E: MSM may be wrong in claiming there is only
one type of STM store, and may be different types of processing information.
- P: prolonged rehearsal may not be needed for LTM. E: MSM says the more you
rehearse info, the more likely it is to transfer to LTM. Craik and Watkins said the type
of rehearsal is more important than the amount. Linking info to existing knowledge
increases likelihood of transfer, even without prolonged rehearsal. E: MSM does not
fully explain how long term storage occurs.
3. Types of long-term memory
AO1:
- Tulving thought the MSM’s view of LTM was too simplistic, so came up with the:
- Episodic memory: LTM store for personal events. Memories of events occurred with
people, places and behaviours involved. Memories have to be consciously retrieved
with effort. Time stamped.
