multi-store model of memory

• who made the multi-store model of memory?

  Atkinson and Shiffrin (1968)
• the multi-store model of memory consists of three basic stores: the sensory store, the short-term store, and the long-term store
• attended information from the sensory register is then transferred to the short-term store
• Sperling (1960)- capacity and duration of SR


  Showed participants a 4 by 3 grid of letters for 50 milliseconds and asked them to recall them. They recalled an average of 4.32 letters from the grid. This shows that sensory memory only lasts a few hundred milliseconds.
• The capacity of STM is limited to about seven items plus or minus two but can be extended through chunking - Miller 1956
• Peterson and Peterson (1959)- duration of STM


  Investigated the duration of the STM through an interference task to prevent rehearsal. They used trigrams and asked the participants to recall them after increasing time intervals (between 3 and 18 sec). They concluded that the STM has a duration of 15 seconds.
• The duration of STM is around 15 seconds
• Miller (1956)- capacity of STM


  Magical number seven plus or minus two is the capacity of the STM
• retrieval from the short term store is based on a rapid scan of the stored information
• phonological similarity effect - letters and words that sound similar are more difficult to recall than dissimilar sounding words from the STM. This suggests that the short term store encodes acoustically because similar sounding things get confused.
• Butler and Roediger (2007)- psy in society


  Participants viewed three lectures over three consecutive days. Some were given a recall test after the lectures and others werent. When they were tested a month later for their memory of the lectures, thoes who had done the recall test recalled more showing that the tests had reinforced the knowledge in the LTM. This shows how psychology can be useful in society.
• Brown and McNeil (1966)- LTM retrieval


  Tip-of-the-tongue phenomena. Recalling some correct features of a memory which is recalling a partial memory trace. Atkinson and Shiffrin think that LTM is not stored as one memory trace but multiple copies.
• Bahrick et al (1975)- LTM duration


  Investigated very long term memory. He did memory tests on the names and faces from high school year books. 90% correct identification after 15 years of leaving school. 70-80% correct identification after 48 years of leaving school. This shows that although LTM deteriorates over time LTM for names and faces is fairly resilient.
• Brady et al (2008) - LTM capacity


  Showed Participants 2500 objects over 5.5H. They then presented them with pairs of objects. When an original object and a different random object were presented correct identification was 92%. When an original object and a similar random object were presented correct identification was 88%. This shows that thousands of images can be stored in the LTM.
• Clive Wearing 


  Suffered from encephalitis. He had an impaired LTM but his STM was intact. He was unable to transfere information from STM to LTM. He had no memory of past events but could remember how to play piano. This case study shows evidence for separate STM and LTM stores but also for the LTM not being one single store.
• Patient HM

  Had brain surgery for epilepsy and his hippocampus was damaged. He then has an impaired LTM but his STM was intact. This shows evidence for separate ST and LT memory stores.
• Patient KF

  Had a motorbike accident and could recall facts but couldn't recall personal events. This suggests that LTM isn't one singular store but we have different stores for skills events and facts etc.
• Serial position effect


  Recall of information at the beginning and end of a list is higher than the middle
• Glanzer and Cunitz (1966)


  Investigated whether the position of a word in a list affected recall. Found that words at the beginning and end were more likely to be recalled than ones in the middle. This was because the words at the start had a chance to be rehearsed. Whilst the start words are being processed the middle words are filling slots in the STM. The end words then displaced the older memory trace for the middle words.
• STM - encoding


  Acoustic
• STM - duration

  15-30 sec
• STM - forgetting


  Decay through displacement
• STM - retrieval


  Sequential scan
• LTM - encoding 


  Semantic and temporal
• LTM - Duration


  Potentially lifetime
• LTM - Capacity

  Potentially limitless
• LTM - forgetting

  Decay over time
• SR - encoding


  one register for each sensory modality
• SR - storage

  50 milliseconds
• SR - capacity


  3-4 items
• STM - capacity

  5-9 items
• SR - forgetting


  immediate decay
• Baddeley (1966) 


  Found that semantically similar words are more difficult to recall from LTM than acoustically similar words. This indicates that the ST and LT stores are separate.