Multi-store Model (MSM)

Multi-store Model (MSM)

1. Short-term memory (STM)

   • Beardsley (1997)
     • Prefrontal cortex active when participants using STM
   • Capacity
     • Miller (1956)
       • 7+/-2
     • Cowan (2001)
       • Reviewed various studies
       • Limited to 4 chunks
   • Duration
     • Lloyd & Margaret Peterson (1969)
       • Maximum of 20 seconds
     • Nairne et al. (1999)
       • Up to 96 seconds
     • Marsh et al. (1997)
       • Only 2 seconds
   • Encoding
     • Baddeley (1966a & 1966b)
       • STM appears to rely on acoustic encoding
     • Brandimote et al. (1992)
       • Can use visual encoding

2. Sensory Memory (SM)

   • Several Stores
     • Eyes
     • Ears
     • Nose
     • Tongue
   • Duration: very limited
     • Sperling (1960)
       • Grid of 12 digits and letters
         • 50 milliseconds (blink of an eye)
         • Asked to write down all 12 items
           • 5 items recalled (42%)
         • Asked to recall one row
           • 3 items recalled (75%)
   • Capacity: very limited

3. Long-term memory (LTM)

   • Squire et al. (1992)
     • Hippocampus active when participants are using LTM
   • Capacity
     • Theoretically unlimited
   • Duration
     • Shepard (1967)
       • 4 months 50% recall
     • Bahrick et al. (1975)
       • Material remember more meaningful
     • Theoretically infinite
   • Encoding
     • Baddeley (1966a & 1966b)
       • LTM encoded semantically
     • Wickens et al. (1976)
       • LTM not exclusively encoded semantically
     • Frost (1972)
       • Long term recall related to visual as well as semantic
     • Nelson and Rothbart (1972)
       • Evidence of acoustic encoding

4. Evaluation

   • Strengths
     • Lead to more research into memory
     • Strong evidence to support
     • First suggestion for how memory works
   • LImitations
     • Over simplfied
     • Structure suggests that STM and LTM are not unitary stores
       • Case study of KF (Shallice and Warrington 1970)
         • Suffered brain damage which lead to difficulties with processing verbal information in STM but a normal ability to process visual information
           • Suggests STM is not a single store
       • Schachter et al (2000)
         • Suggested four long term stores
           • Episodic memory
             • Memory of what you did yesterday etc.
           • Perceptual representation system (PRS)
             • Memory related to perceptual priming of specific stimuli which have been see before
           • Procedural memory
             • Memory for riding a bicycle or how to read etc.
           • Semantic memory
             • memory for knowledge of the world, including words
     • Rehearsal vs. processing
       • Craik and Lockhart (1972)
         • Proposed different kind of model to explain memory
           • Enduring memories created by processing rather than rehearsal
     • How separate are STM and LTM?
       • Logie (1999)
         • STM relies on LTM, therefore it can not come first
       • Ruchkin et al (2003)
         • Used words and pseudo words to test brain activity - more brain activity for actual words suggesting other parts of the brain were used
           • STM is just apart of LTM that is activated when needed.
       • Glenberg et al (1997)
         • Maintenance rehearsal not as effective as elaborate rehearsal in creating memories