MSMM
MSMM proposed by Atkinson and Shiffrin
- 3 different types of memory
- linear model
- rehearsal required to prevent decay
Sensory Register
SENSORY REGISTER
stimulus from enviroment passes into SR
attention neeed to pass info into STM (Sperling)
5 Sensory Stores:
- Iconic - coded visually
- Echoic - coded acoustically
- Haptic
-Short duration
-High capacity
Short Term Memory
SHORT TERM MEMORY
infomation coded acoustically (Baddeley)
-limited capacity (7+/-2, Miller, Jacobs)
-duration 18-30secs unless rehearsed (Peterson and Peterson)
maintenance rehearsal retains info to eventually pass into LTM
Long Term Memory
LONG TERM MEMORY
information coded semantically (Baddeley)
-unlimited capacity
-duration lasts a lifetime (Bahrick et al)
info recalled from STM by retrieval
KEY STUDIES
KEY STUDIES
- Sperling - SR
- Jacobs - STM, capacity
- Miller - STM, capacity
- Peterson and Peterson - STM, duration
- Baddeley - STM & LTM, encoding
- Bahrick et al - LTM, duration
SPERLING
SPERLING
- ppts shown grid for less than half a second to see how many letters they could recall
- could only recall 5 letters but were aware there were more
- high capacity but delays quickly
- duration less than half a second
- attention needed to pass into STM
JACOBS
JACOBS
- digit span
- mean span for digits 9 items
- mean span for letters 7 items
MILLER
MILLER
- STM can be extended by chunking
- makes info more meaningful through organising it with existing knowledge in LTM
- suggest STM capacity is 7+/-2 items
PETERSON AND PETERSON
PETERSON AND PETERSON
- gave ppts a trigram and a 3 digit numbere
- ppts counted backwards from 3 digit number to prevent rehearsal
- on each trial there were retention intervals of increasing lengths of time
- found longer interval delay = less trigrams recalled
- 80% after 3 secs, 10% after 18 secs
BADDELEY
BADDELEY
- gave lists of words to 4 ppts groups
- acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar words lists
- STM - recall immediatley after hearing list
- LTM - recall after 10 min prolonged rehearsal
- acoustically similar harder to recall from STM, info codeed acoustically
- semantically similar harder to recall from LTM, info coded semantically
BAHRICK ET AL
BAHRICK ET AL
- tested photo recognition from high school yearbooks
- tested free recall on names in graduating calss
- ppts tested withing 15 years accurate 90% in photo, 60% free recall
- after 48 years, photo 70%, free recall 30%
- shows LTM can last a very long time
EVALUATION (4)
EVALUATION
- Supported by scientific research
- Issues with MSMM taken from real life
- Issues with research that support MSMM
- Case study of CW
EVAL: Seperate stores supported by scientific research
Seperate stores supported by scientific research
- fixed procedures, produce reliable results
- suggests findings are valid
- produce empirical evidencee
- high control - fairs teests
- e.g Peterson and Peterson, Sperling, Baddeley
- strength = scientific credibility
EVAL: Issues with MSMM taken from real life
Issues with MSMM taken from real life
- somtimes info doesnt enter LTM despite repeated attempts at prolonged rehearsal e.g exam revision
- limitation = suggests prolonged rehearsal ineffective
- opposite is true, events enter LTM without prolonged rehearsal e.g obscure gossip not rehearsed but didnt decay
- limitation = prolongede rehearsal not always neeeded
- weakness, lowers external validity
EVAL: Issues with research that supports MSMM
Issues with research that supports MSMM
- e.g P&P used trigrams when testing duration of STM
- artificial stimuli = word lists, digit spans
- doesnt reflect real life, names,events,places
- low external validity
- C/A gives higher control as stimuli is equally meaningless to all ppts = higher validity
EVAL: Case study of Clive Wearing
Case study of Clive Wearing
- damage to hippocampus = cant form new LTMs but existing LTMs intact
- STM only had 7 second duration
- demonstrates STM and LTM are 2 separateee stores and function independently
- model explains real life behaviour = high external validity
