multi store model

• Atkinson and Shiffrin (1968) proposed the three part, multi store model of memory

  
• sensory register is first part: iconic and echoic memory
• sensory register: all stimuli from the environment (someone talking) enters into the sensory register. this part of the memory comprises several registers (sensory memory stores) one for each of the 5 senses
• sensory register: coding is dependant on the sense( eg. the store coding for visual information is the iconic memory and the store coding for sound is echoic memory)

  the duration of material in the sensory register is very brief, less than half a second however the capacity for sensory register is very high, for example there are over 100 million cells in one eye, each storing data

  information only passes into the memory system if you pay attention to it
• short term memory: information in the short term memory is coded mainly accousitically and lasts around 18 seconds (unless it is rehersed) this makes STM more of a temporary store

  it is a limited capacity store so it can only hold so much information before other things begin being 'forgotten'. the STM can hold between 5-9 peices of information (7+-2), cowen's research shows its more likely 5 than 9
• maintainance rehersal: occurs in STM when we rehearse information to ourselves again and again, we can keep infformation in STM longer than 18 seconds as long as we rehearse it, if we rehearse long enough then it gets passed into LTM
• long term memory: potentially permanant store for information that has been rehearsed for a prolonged time. LTM are mainy coded sematically and psychologists believe that the duration of LTM could be up to a lifetime (bahrick et al. found many participants in their study could recognize the names and faces of their classmates 50 years after graduation)

  according to the MSM when we want to recall infromation from the LTM it must be bought back to the STM by a process called retrieval
• strength of MSM: real world application:

  support from studies showing that STM and LTM are different. baddely (1966) found that we tend to mix up words that sound similar when we are using our STM but we mix up words that have similar meanings when we are using our LTM, further support comes from case studies on capcaity and duration, these clearly show that LTM and STM are speerate stores, as suggested by the MSM
• limitation of MSM: more than one STM store

  evidence of more than one STM store. shallice & earrington (1970) studied a client they called KF who had amnesia, KF's STM was very poor for digits when they were read out to him but recall was much better wehn he read the digits to himself. further studies on KF found that there could even be another STM store for non verbal sounds (noises)

  this evidence suggests that the MSM is wrong in suggesting that there is only one STM store processing different kinds of information (eg. visual, auditory)
• limitation of MSM: elaborative rehearsal

  prolonged rehearsal is not needed to transfer information to the LTM. according to MSM, most important part about rehearsal is the amount of it you do the more likely it is to transfer to LTM (prolonged rehearsal) craik and watson (1973) found the type of rehearsal is more important than the amount of rehearsal (elaborative rehearsal)

  this occurs when you link new information to existing knowledge or think about what it means, means info can be transfered without prolonged rehearsal

  suggests MSM does not fullu explain how LTM storage is achieved
• CASE OF HM

  HM underwent brain surgery to relieve his epilepsy, procedure not fully understood when performed, removed his hippocampus from both sidees of his brain, we now know this is central for memory function. when his memory was assessed in 1955 he thought it was 1953 and that he was 27 years old (he was actaully 31). he could not form new long term memories (didn't know what he had for breakfast, could read the same magazine over again and not know) however he performed well on a test of immediate memory span, a STM test