memory

• Short term memory definition (STM)


  memory for immediate events
• Long term memory definition (LTM)


  memory for events that have happened in the past
• Duration definition


  a measure of how long memory lasts before it is no longer available
• Coding definition


  the format in which information is stored in the various memory stores
• Capacity definition


  how much information can be held in a memory store
• STM duration experiment (procedure)


  Peterson & Peterson (1959)

  - 24 undergraduate students

  - 8 trials

  - trigram (consonants) + reciting a 3 digit number backwards

  - recall trigram after retention intervals of 3, 6, 9, 12, 15, 18 seconds
• evaluation of studies (acronym + what it is)


  G: generalisation eg age, gender, culture etc.

  R: reliability-is it repeatable? was it repeated?

  A: application-does it provide evidence? in life?

  V: validity-any external distractions? representative?

  E: ethics- was this consensual? how did researchers address this?

  M: mundane realism- is this applicable to everyday life? artificial task? how was this studied.
• STM capacity experiment (procedure)


  Jacobs (1887)

  -digit span test

  - 4 digits, then 5, then 6, then 7 etc.. (gets longer)
• STM capacity experiment (results)


  - average span for digits: 9.3 items

  - average span for letters: 7.3 items
• STM capacity experiment (results) - psychological research


  Miller (1956)

  - reviewed psychological research into STM

  - STM: 7 (+/- 2) items

  - (5-9 items)
• Chunking definition


  grouping items into units/chunks helps aid recall

  (e.g phone calls)
• Sensory Register (MSM)


  coding - depends on the sense involved

  eyes = iconic memory

  sound = echoic memory

  capacity - high

  duration - less than half a second
• STM (MSM) - coding capacity and duration


  coding - acoustic

  capacity - 5-9 items

  duration - less than 30 seconds
• LTM (MSM) - coding capacity and duration


  coding - semantic

  capacity - unlimited

  duration - lifetime
• Case of KF


  Tim Shallice and Elizabeth Warrington (1970)

  
  

  - amnesic patient suffered brain damage from motorcycle accident

  - LTM remained fairly intact but STM was damaged

  - digit span of 2 items

  - digit span when presented visually it was better (basically normal) but worse when acoustically given

  - shows there are two types of STM; one to process visual material and one to process auditory material

  
  

  Shallice and Warrington (1974)

  - KF STM for non-verbal sounds eg noises was intact therefore this showed there are three types of STM

  - one for verbal and one for non-verbal sounds

  - spatial memory; it appears that in other studies of amnesic patients that these forms of memory may be separate

  - this there are three types of STM; verbal, visual, spatial
• Explanations for forgetting - Interference


  when one memory disrupts the ability to recall another - more likely to happen in memories are similar
• Proactive interference


  past/old memories disrupt recall of newer memories
• Retroactive interference


  new memories disrupt recall of past/older memories
• Anxiety


  an unpleasant emotional state likely caused by stress, resulting in physiological arousal (increased heart rate , blood pressure, breathing and sweatiness)