Memory redo

• Coding


  How information is stored in the memory
• Capacity


  How much information a memory store can hold
• Duration


  How long a memory store can hold information
• Coding of memory stores


  Short-term memory: Acoustically coded (sounds)

  Long-term memory: Semantically coded (meaning)
• Research into coding 


  Baddeley and Hitch -

  Gave participants lists of words either semantically (dis)similar or acoustically (dis)similar

  Short-term recall was worse for acoustically similar words because of acoustic confusion

  Long-term recall was worse for semantically similar words because of semantic confusion
• Research into duration

  Peterson and Peterson -

  Asked participants to recall nonsense trigrams in increasing intervals after counting backwards to prevent maintenance rehearsal

  Bahrick -

  Asked participants to recall and match names of old schoolmates with yearbook pictures
• Duration of memory stores


  Short-term memory: 18-30 seconds

  Long-term memory: 45+ years (very long time)
• Capacity of memory stores

  Short-term memory: 7+/-2

  Long-term memory: Unlimited
• Research into capacity of memory stores

  Miller -

  Based on ideas that things often come in 7s so we are predisposed to remembering this number of things

  Chunking method can help with more recall

  Jacobs -

  Asked participants to repeat lists of letters or digits to find 'digit span'
• Multi-store model of memory

  Proposed by Atkinson and Shiffrin

  Made up of

  • sensory register
  • short-term memory store
  • long-term memory store
• Sensory register


  Collects information from environment from all 5 senses

  Sperling showed it had very short duration - showed participants grid of letters and digits for 50 milliseconds

  Recall of whole grid was 42%

  Recall of one line was 75%
• How information moves in msm

  Sensory register -> STM: Attention

  STM -> LTM: Maintenance rehearsal -> Prolonged rehearsal

  LTM -> STM: Retrieval
• Strengths of MSM


  Research support - Baddeley showed that their must be different stores for STM and LTM
• Limitations of MSM


  Contradictory evidence - Shallice and Warrington KF study: had poor recall when digits read out to him, but better when read himself

  Craik and Watkins - suggests type of rehearsal is more important than amount of time

  - elaborative rehearsal - when you link information to something you already know

  Oversimplified
• Types of long-term memory(Tulving)


  Episodic

  Semantic

  Procedural
• Episodic memory


  Memory of past events

  • time-stamped
  • explicit (conscious recall)
• Semantic memory


  Knowledge of facts

  • not time-stamped
  • explicit (conscious recall)
• Procedural memory


  Knowledge of how to do things

  • not time-stamped
  • implicit (unconscious recall)
• Strengths of types of long-term memory

  Evidence support

  • Case studies HM and Clive Wearing: Both had intact semantic and procedural memories in tact, but lost episodic memory

  Real-life application - allows psychologists to help people as they lose their memory
• Limitations of types of long-term memory

  Conflicting research - Buckner and Petersen concluded that semantic memory is located in the left prefontal cortex and episodic on the right

  - Tulving found that encoding of episodic memory to be on the left, and retrieval of episodic memory to be on the left

  Clinical studies cannot be generalised and take an idiographic approach
• Working memory model


  Proposed by Baddeley and Hitch

  Made up of

  • Central executive
  • Phonological loop
  • Visuo-spatial sketchpad
  • Episodic buffer
• Phonological loop


  Coded acoustically

  Made up of

  • Phonological store: stores words you hear
  • Articulatory process: allows maintenance rehearsal

  - capacity of which is around 2 seconds
• Visuo-spatial sketchpad


  Subdivided by Logie into

  • Visual cache: stores visual data
  • Inner scribe: records arrangement of objects
• Episodic buffer


  Added by Baddeley in 2000

  Temporary store of information that integrates information from other stores and links to LTM and perception
• Strengths of WMM


  Shallice and Warrington KF study: had poor STM ability for auditory information but could process visual information normally

  Baddeley dual-task studies: Participants did well carrying out visual and verbal tasks at the same time, but struggled when tasks were of the same nature
• Limitations of WMM


  Lack of clarity over role of central executive

  Ignores LTM
• Interference theory


  Proactive interference: old memories disrupt new memories

  Retroactive interference: new memories disrupt old memories
• Interference theory - study

  McGeoch and McDonald had participants learn word lists to 100% recall.

  When participants were asked to recall the list of words after learning a similar set of words, their recall was worse than when participants had to learn a completely unrelated list, recall was highest
• Interference theory strengths


  Evidence support - Baddeley and Hitch: asked rugby players to recall names of those they played against. Those whoplayed more games had worse recall

  Coenen and Luijtelaar asked participants to recall a list of words learned either before or after taking diazepam. Recall was best when words were learnt before taking the drug, because it prevented new information reaching the brain
• Interference theory limitations


  Tulving and Pstoka showed that if asked to recall a list with the aid of cues, recall was higher than asking without. Showing interference only results in temporary loss

  Low mundane realism

  Artificial stimuli
• Retrieval failure forgetting theory

  Tulving's encoding specificity principle - states that a cue must be present at encoding and at recall, if cues are different, some forgetting may occur

  Context-dependent forgetting - recall depends on external cue

  State-dependent forgetting - recall depends on internal cue
• Retrieval failure - studies

  Godden and Baddeley - water and land

  Carter and Cassaday - antihistamines
• Retrieval failure strengths


  Real-life application - cues can help with real life forgetting

  Research support - Eyesenck and Keane suggest retrieval failure is one of the main reasons for forgetting
• Retrieval failure weaknesses

  There aren't as significant differences like water vs land

  Low mundane realism

  Artificial situation
• Misleading information - leading questions

  Loftus and Palmer - showed participants a video of a car crash and asked them to estimate the speed however, change the verbs in the question

  • smashed
  • hit
  • contacted
  • bumped
  • collided

  The speed with the word 'smashed' was the fastest and 'contacted' produced the lowest mean speed
• Leading questions effects


  Response bias - the wording has no effect on the memory, but influences the participants answer

  Substitution explanation - the wording of the question changes the participants memory (those who heard smashed were more likely to report broken glass when there was none)
• Misleading information - post-event discussion

  Gabbert - placed participants in pairs and asked them each to watch different videos of a car crash filmed at different angles

  Participants discussed what they saw before completing a recall test

  71% mistakenly recalled aspects they wouldn't have been able to see
• Post-event discussion effects


  Memory contamination - the memories may be distorted or altered because they combine their own memories with others

  Memory conformity - witnesses often change their memory to go along with each other because they believe the other is right (informational social influence)
• Misleading information strengths


  Real-life application - can help improve the criminal justice system
• Misleading information limitations


  Lab setting means artificial situation

  EWT is more accurate for some events than others which cannot be explained by substitution explanation

  Skagerberg and Wright found that post-event discussion actually changes memory of hair colour and cannot be explained by memory conformity