multistore model

• Sensory memory


  When information comes in from the senses it needs to be stored for a very small amount of time until the body's processing systems can decide what to do with it
• The brain has to process all the information from the senses even though the bulk of it (around 99%) will be discarded as it is simply not needed
• Sensory memory (SM)


  The processing of sensory information is carried out in
• Sensory memory


  • The duration of SM is around 1/2 a second, up to several seconds at the very most
  • The capacity of SM is between 12 to 16 items
  • The SM encodes using all 5 modalities (senses)
• Types of sensory memory


  • Iconic memory
  • Echoic memory
  • Haptic memory
  • Olfactory memory
  • Gustatory memory
• Iconic memory


  Retaining information that comes from sight or light stimulus
• Iconic memory


  • You remember how the theatre or cinema looked as the light went down
• Echoic memory


  Retaining information that comes from sound or auditory stimulus
• Echoic memory


  • You can recall a song you just heard in your head
• Haptic memory


  Retaining information that comes from touch
• Haptic memory


  • You can recall how it feels when rain hits your skin
• Olfactory memory


  Retaining information that comes from smell
• Olfactory memory


  • The smell of fresh bread may make you feel happy as it reminds you of something pleasant
• Gustatory memory


  Retaining information that comes from taste
• Gustatory memory


  • The taste of something may remind you of your childhood, like fish fingers and chips
• Short-term memory (STM)


  Has the ability to hold a small amount of information for a relatively short period of time
• Short-term memory


  • The amount (capacity) and duration of STM is greater than sensory memory but smaller than long-term memory
  • It is seen more as a holding device before memory is forgotten/lost or moved to long-term memory
• Capacity of STM


  Experiments conducted by Miller (1956) indicate the capacity of STM is 7 items or chunks plus or minus 2 (5-9 items)
• Miller's experiment


  • He asked participants to recall information, adding an extra bit as he moved on: A bit like the game 'I went to the shops'
  • Starting participants with two or three words to recall, he gradually built it up until they made an error
  • It was found that most participants struggled with between 5-9 words
• Miller's findings


  This is known as 'Miller's Magic 7'
• Jacobs (1887) experiment


  • He completed a similar experiment using digits with 443 female students
  • His results were similar to Miller's, with 7.3 being the average recall
• Jacobs' study supports Miller and suggests his study is valid
• Miller's study is also reliable as it is easy to copy and it is especially reliable as the results are more often than not the same
• As it is a lab study extraneous variables would have been controlled
• However, it could be argued it lacks ecological validity as the task bears little resemblance to real life
• Duration of short-term memory

  The duration of short-term memory is around 18-30s
• Peterson and Peterson (1959) study


  • They gave participants non-sensical three-letter trigrams to learn
  • The participants had to recall the trigram in the correct order after a delay of either 3s, 6s, 9s, 12s, 15s or 18s
  • During this delay they were asked to complete a distraction task: usually counting backward from 300 in 3s
  • A graph of the correctly recalled trigrams over time was plotted and was shown to be a decay curve
  • This demonstrates that over time the memory seems to decay
  • The graph was extrapolated to show that after the 30s recall in STM would be zero
• Peterson and Peterson stated that the duration of STM was 18-30s
• Peterson and Peterson conducted a well-controlled study and many extraneous variables would have been removed or controlled for
• But it could be that previous trigrams, maybe similar to the one being recalled, interfered with the memory and that is why the participant made the mistake, challenging the validity of the study
• Encoding in short-term memory

  Short-term memory encodes acoustically or using sound
• Baddeley (1966) study


  • He gave participants four lists of words to learn: acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar
  • He found the acoustically similar words had the worst recall
  • There was no difference in STM for the semantically similar and dissimilar words
  • From this, he concluded that STM relied on acoustic encoding to process information
• This is a lab experiment so is highly controlled, with extraneous variables taken care of
• However, it also means that it lacks ecological validity as the tasks do not relate to real life
• The words had little to no meaning for participants and so they were harder to recall
• Types of long-term memory (LTM)

  • Episodic
  • Procedural
  • Semantic
• Episodic memory


  The part of LTM that relates to experiences a person has had or events from their life
• Episodic memory


  • A 16th birthday party
  • The first time someone sees the sea
  • Someone's first psychology lesson
• Procedural memory


  The part of LTM involved in knowing how to do certain actions or skills
• Procedural memory


  • Knowing how to ride a bicycle
  • Knowing how to swim
  • Knowing how to make a cup of tea