memory

• sensory store has an unlimited capacity, 2ms duration and codes in any format
• STM has a 7+/-2 capacity, 18-30s duration and codes acoustically
• LTM has an unlimited capacity and duration, codes semantically
• information enters the sensory store from the environment, passes to the STM by paying attention, remains in the STM by maintenance rehearsal and transfers to the LTM by elaborative rehearsal
• Jacobs digit span test

  average recall of 7.3 letters and 9.3 words

  supports capacity of 7+/-2
• Peterson and peterson,

  24 psychology students recall nonsense trigrams every 3s

  after 3s 80% could recall, after 18s less than 10% recall

  duration of 18-30s
• sensory has

  iconic store to code visual information

  echoic store to code auditory information
• Baddeley gave 4 word lists

  people who recall immeadiately struggle with acoustically similar words, people who recall after twenty minutes struggle with semantically similar

  STM codes acoustically and LTM codes semantically

  causes confusion
• sperling

  presented participant with 3 rows of 12 letters

  asked to look for 1/20th of a second and recall

  could recall 4-5 of 9 letters as they were mentally registered but forgotten when asked to recall

  information stored briefly in sensory and lost when not attended to
• Bahrick et Al

  392 american graduates, asked to match yearbook pictures to names

  90% can match 14 years later

  60% can match 47 years after
• evaluate bahrick et al

  low population validity as all the participants were american graduates

  high ecological validity

  does not take into account extraneous variables like prior contact with classmates/looking at yearbook
• serial position

  cognitive bias

  participants remember words presented at beginning and end of list (primary and recency effect)
• episodic memory is timestamped

  personal events from your life

  declarative and explicit memory

  conscious effort to recall

  easiest to forget

  level of emotion felt at the time influences strength of memory
• semantic memory

  general knowledge of the world

  memories not time stamped

  declarative/explicit so requires conscious effort to recall

  how deeply processed influences strength
• procedural memory

  how to/actions

  non declarative/implicit so does not require conscious effort to recall

  very resistant to forgetting

  how many times practised influences strength
• HM had his hippocampus removed

  STM was intact but LTM could not form new memories

  drew a star by reflection 3x for 10 days

  he improved but could not recall

  suggests procedural and episodic are separate stores of LTM
• Clive wearing

  procedural memory intact as he could play piano

  episodic memory damaged as he could not remember questions whilst answering them or people

  memory of 7-30s
• central executive

  manages attention

  filters sensory information and passes to slave systems

  4 items capacity
• Phonological loop

  articulatory process (inner voice), holds information via vocal repetition

  phonological store (inner ear), holds words recently heard

  2s capacity

  keeps information in order of arrival
• episodic buffer

  temporary storage that integrates information

  4 chunks capacity
• visuospatial sketchpad

  visual cache, passive store of form and colour

  inner scribe, holds relationships between objects in 3D space
• Hunt

  participants do dual task

  moving lever (psychomotor) and visual pattern test (visual intelligence)

  when performed together, performance deteriorated

  shows central executive has limited capacity
• prabhakaran et al

  fMRI scan found greater right frontal brain activation for combined visual and spatial information but greater posterior activation for non-combined information

  biological evidence for episodic buffer
• Berz

  participants listened to instrumental music whilst completing another task

  performance was not impaired

  WMM does not account for acoustic memory
• central executive is regarded as vague, little research available
• Shallace and Warrington

  KF had motorcycle accident that caused brain damage

  auditory memory loss limited to verbal material (letter/digit), not meaningful sounds like phone rings

  still recall verbal stimuli

  shows brain damage restricted to phonological loop
• interference theory

  memories distorted/changed as a result of conflicting memories
• proactive interference

  old information interferes with new

  occurs when information in similar
• retroactive interference

  new information interferes with old

  occurs when information is similar
• Keppel and Underwood

  presented nonsense trigrams and prevented rehearsal as participants counted back in 3s until recall

  participants remember trigrams presented first, irrespective of interval length

  Shows proactive interference as earlier letters transfer to LTM and interferes with new learning
• Schmidt et Al

  211, 11-79 year old participants chose randomly from questionnaire

  shown map around their school with street names replaced by numbers

  those who moved home more, remembered less

  retroactive interference
• Baddeley and Hitch

  sample of rugby players who played all season and players who missed some games due to injury

  asked to recall names of teams played earlier in season

  those who played more remembered less

  retroactive interference
• retrieval failure happens because we cannot access a memory due to lack of cues
• encoding specifity principle

  proposed by tulving

  cues must be present at encoding and retrieval for effective recall
• External cues are the context (environment)

  internal cues are your state (mood, emotions)
• Godden and Baddeley

  learning and recalling a list of words on land or water

  recall was 40% lower when conditions were not matched

  context dependent cues
• Carter and Cassaday

  participants given antihistamines with mild sedative, become drowsy which is different internal physiological state from being awake

  learn and recall word list better when conditions are matched

  state dependent cues
• Tulving and Psota

  participants given 6 word lists of 24 words and asked to recall

  repeat but give names of categories in lists

  recall improved by 70% because of cues
• eyewitness testimony

  account a bystander or victim gives in the courtroom of criminal incident
• Reconstructive memory

  change unfamiliar details in memories to familiarised concepts due to schemas

  recall subject to personal interpretation