coding
the format inn which information is stored in the various memory stores.
Capacity
the amount of information that can be held in a memory store at a given
Duration
the length of tie information can be held in a memory
short term memory
the limited capacity memory store .coding is mainly acoustic , capacity between 5 - 9 items on average , duration is between 18 - 30 seconds .
Long term memory
the permanent memory store . coding is mainly semantic , it has unlimited capacity and can store memories for up to a life time .
Jacobs (1887 )
Aim : research capacity of STM
Procedures : developed a technique to measure digit span how many times an individual can remember , in sequence and repeat back in order .
Findings : found the mean span for digits across participants was 9.3 items . found the mean span for letters across participants was 7.3 .
conclusion : memory can hold 7- 9 items
miller 1956
aim - research capacity of STM
Procedures - observed the things come in sevens : days of the week , notes on a music scale , deadly sins etc . also used the digit span technique but “chunked. “ items into groups e.g words and sets of numbers
Findings : found people could recall 5 words , as well as they can recall 5 letters ( via chunking)
Conclusion - used the term ‘the magical number 7 ‘ to describe the capacity of the STM.
Peterson and Peterson (1956)
aim - research duration of STM
Procedures 24 students took part in 8 trials ad were given a consonant syllable / trigram such as BNT and a three digit number and asked to count backwards to prevent rehearsal . on each trail , they were sopped after either 3 , 6 ,9, 12 , 15 or 18 seconds .
Findings : found that STM lasts about 18 seconds after this very few people correctly recall the consonant syllable.
Conclusion -it suggests that STM may have a very short duration , unless rehearsed .
Bahrick (1975)
aim - research duration of LTM
procedures : tested recall of people participants had gone to school with using photo recognition ( 50 photos from a persons year book ) and free recall ( participants recalled all the names of their graduating year )
findings - found 90 % accuracy for photo recognition for people who had graduated within 15 years and 60% accuracy for free recall . after 48 years , photo recognition recall Was about 70% and 30% for free recall .
conclusion LTM lasts a very long time .
Baddeley
aim - to asses whether coding in STM and LTM. was mainly acoustic ( sound ) or semantic ( meaning)
Procedures - 4 sets of word lists :
- acoustically similar
- acoustically dissimilar
- semantically similar
- semantically dissimilar
participants had to recall the order of the list of words this was done immediately -to assess STM , after 20minutes - to assess LTM
Findings : immediate recall
participants given the list of acoustically similar words had the worst recall , they confessed the similar sounding words
delayed recall
participants given a semantically similar words had the worst recall .
they confused the similar meaning words .
conclusion ; suggests STM is acoustically coded , because people were able to remember the other lists of words fine .
LTM is semantically coded because people were able to remember the other lists of words fine .
multi store model of memory
a representation of how memory works in terms of the three stores called sensory register , short term memory and long term memory .it describes how information is transferred from one store to another . how its remembered and forgotten .
sensory register
the memory stores for each of our 5 senses , vision ( ionic store ) and hearing ( echoic ) . coding in the ionic sensory register is visual and in the echoic sensory register it is acoustic . the capacity of the sensory register ism huge and info lasts a very short time - less the half a second .
sensory register - CODING, CAPACITY , DURATION
CODING - iconic , echoic , haptic , gustatory , olfactory
CAPACITY - high
DURATION - less than half a second
STM - CODING , CAPACITY , DURATION
CODING - acoustic
CAPACITY - 5 -9
DURATION - 18 - 30 seconds
LTM - CODING , CAPACITY , DURATION
CODING - semantic
CAPACITY - unlimited
DURATION - unlimited
Who studied patient KF
Shallice and Warrington
Explain Patient KF study
-conducted by Shallice Warrington
- KF had amnesia caused by a motorcycle accident which damaged his STM
- Specifically damaged his verbal recall
- Found KF STM for digits was very poor when tested he was only able to recall 2 items verbally
- However his recalls much better when he was able to read the digits himself.
How can MSM be used to explain the behaviours shown by KF
-Suggests/ demonstrates that STM is not a single, unitary store and may have further components.
how can patient KF be used to evaluate MSM?
- it suggests that there are different aspects of STM- one for visual info and one for auditory info.
Explain the case of HM and how it can be used to evaluate MSM
- Supports MSM
- Supports the central features of the model-that there are two separate and independent memory stores, STM and LTM
- HM is evidence that it is possible to suffer damage to one of these stores with other remaining relatively unaffected.
-Hm had surgery to help with his epilepsy where he had his hippocampus removed. - HM’s LTM was badly damaged he had no memory for events that happened after his surgery and then he struggled to remember things occurred just hours or even minutes earlier , But his STM was not effected -he could recall info presented immediately but none of this could be transferred to the LTM
- He was unable to form any new LTM after this surgery.
what are the types of LTM
Episodic , Semantic , Procedural
Episodic memory
a LTM for personal events . includes memories of when the event occurred and of the people , objects , places and behaviours involved . memories from this store have to retrieve consciously and with effort .
Semantic memory
LTM store of our knowledge of the world . this includes facts and our knowledge of what words and concepts mean . these memories usually also need to be recalled deliberately .
Procedural memory
a long term memory store for our knowledge of how to do things , this includes our memories of learned skills . we usually recall these memories without making a conscious or deliberate effort .
