multi-store model of memory

• 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 sensory information 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

  • Duration is around 1/2 a second, up to several seconds at the very most
  • Capacity is between 12 to 16 items
  • Encodes using all 5 modalities (senses)
• 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
• Short-term memory (STM)

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

  • Amount (capacity) and duration 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
• Short-term memory capacity

  Experiments indicate the capacity is 7 items or chunks plus or minus 2 (5-9 items)
• Miller's experiment on short-term memory capacity

  1. Participants recalled information, adding an extra bit as he moved on

  2. Most participants struggled with between 5-9 words
• 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
• Miller's study lacks ecological validity as the task bears little resemblance to real life
• Short-term memory duration

  Duration is around 18-30s
• Peterson and Peterson's study on short-term memory duration

  1. Participants had to recall trigrams after a delay of 3s, 6s, 9s, 12s, 15s or 18s

  2. During the delay they had to complete a distraction task to prevent rehearsing

  3. A graph of correctly recalled trigrams over time showed a decay curve, extrapolated to 30s
• Peterson and Peterson's study challenges the validity of the decay curve, as it could be due to interference from previous trigrams rather than true decay
• Encoding in short-term memory

  How the information is processed from the senses into the memory itself
• Encoding in short-term memory

  Short-term memory encodes acoustically or using sound
• Baddeley's study on encoding in short-term memory

  1. Participants recalled lists of words that were either acoustically similar, acoustically dissimilar, semantically similar, or semantically dissimilar

  2. Acoustically similar words had the worst recall, supporting acoustic encoding in short-term memory
• Baddeley's study lacks ecological validity as the words had little to no meaning for participants, making recall harder
• Types of Long Term Memory

  • 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
• Semantic memory

  The part of LTM that involves knowing and recalling facts, concepts and meanings
• Semantic memory

  • Knowing that Paris is the capital of France
  • Knowing that the number 3 is between the numbers 2 and 4
  • Knowing that the word 'bank' has two meanings: A place where money is stored, or the edge of a river
• Long Term Memory (LTM)

  The part of the memory that holds information indefinitely, having a longer duration and larger capacity than Short Term Memory (STM)
• As far as is known, long-term memory has an unlimited capacity
• There has never been a known case of someone not being able to learn something new or retain a memory because their LTM is full
• Duration of long-term memory

  The duration of LTM is as long as a person's lifetime
• Most people cannot recall episodes from their life before the age of two, known as Childhood or Infantile amnesia
• Evidence for the duration of long-term memory

  • Bahrick (1975) found that graduates could accurately match names to faces from their high school yearbook 47 years later 60% of the time
• Bahrick's study has good ecological validity as looking at old photographs and trying to recall names is a task most people do in real life
• The study never really explains why recall becomes worse over time, is it a side effect of old age or that there is some limit to duration which impacts the memory as we get old and continue to make more memories
• Encoding in long-term memory

  How the information is processed from the senses into the memory itself
• Long-term memory encodes semantically or by meaning, as shown by a study by Baddeley (1966)
• Baddeley's study on encoding in long-term memory

  1. Gave participants four lists of words to learn

  2. Recalled the words after 20 minutes

  3. Found semantically similar words had the worst recall
• Baddeley concluded that LTM relied on semantic encoding to process information