Multistore model of memory

• Coding

  How information is processed
• Capacity


  How much information it can hold
• Duration

  How long information can be stored for.
• Sensory register/store: Coding

  The store receives information from our senses.
• Sensory store: Duration

  Information doesn't last long (only seconds) before passing into STM.
• Sensory store: Capacity

  Lots of information enters this store- we only remember it if we pay attention.
• Iconic

  Visual signals
• Echoic

  Auditory information
• Short term memory: Coding

  STM codes acoustically (by sound). Baddeley found this through getting participants to recall lists of words. He found that ppts performed worse in STM recall tasks where word lists sounded similar. He found that ppts performed worse in LTM recall tasks where word lists has the same meanings. This meant that LTM codes semantically. This supports that SR, STM and LTM are different stores as they code differently.
• Short term memory: Capacity

  The capacity of STM is 5-9 items, however, you can often remember more by 'chunking' items together. Jacobs did a digit span test, with a sample of 433 female students. He found that the average span was 7.3 letter and 9.3 words. This suggests that STM has a smaller capacity than LTM.
• Short term memory: Duration

  STM lasts approximately 18 seconds. Peterson and Peterson had participants remember trigrams and then count backwards in 3s until asked to recall the trigram. Participants struggled to remember after 18s. This supports the idea of different stores as the duration is shorter/worse than LTM.
• Role of rehearsal and maintenance rehearsal


  Rehearsal of information maintains it in STM, information in STM is transferred to LTM if information is rehearsed (elaborative rehearsal). If maintenance rehearsal doesn't occur, information is forgotten.
• Multistore model of memory

  A) Information from environment via the senses

  B) Decay

  C) Sensory register/store

  D) Short-term memory

  E) Attention

  F) Rehearsal

  G) Transfer/ consolidation

  H) Long-term memory

  I) Retrieval

  J) Absence of retrieval cues/ interference

  K) Decay/ displacement

  
• Long-term memory: Coding

  Information is encoded semantically. This is supported by Baddeley who found that in list 3 (semantically similar words) was the least effectively recalled list in his research after a 20 minute wait.
• Long-term memory: Capacity

  LTM's capacity is unlimited.
• Long-term memory: Duration

  LTM's duration is potentially a life time.
• Long-term memory duration- Bahrick et al (1975): Aim


  Aimed to establish the existence of very long-term memory and to see whether there was a difference between recall and recognition.
• Long-term memory duration- Bahrick et al (1975): Procedure

  Investigators tracked down graduates over a 50 year period from a certain high school in America. 392 students were shown photographs from their year book and were split into two groups; recall and recognition. In the recognition group: for each photo, ppts were given a list of names and asked to match names to faces. In the recall group: no list was given, ppts just had to name the people.
• Long-term memory duration- Bahrick et al (1975): Findings


  Recognition:

  • 90% correct 14 years after graduation.
  • 80% accurate after 25 years
  • 75% accurate after 34 years
  • 60% accurate after 47 years.

  Recall:

  • 60% accurate after 7 years.
  • Less than 20% accurate after 47 years.
• Long-term memory duration- Bahrick et al (1975): Conclusion


  Information that is stored in the LTM can be returned to STM by a process of retrieval.