memory

• Multi-store model of memory

  • Developed by Atkinson and Shiffrin (1968)
  • Believed it was a unitary system
  • The system is linear
• Multi-store model of memory

  1. Stimulus from environment passes into sensory register

  2. Information encoded based on type (auditory/visual)

  3. Attention paid, information passed to short-term memory (temporary store)

  4. Information can be forgotten, rehearsed or retrieved

  5. If rehearsed, can be moved to long-term memory

  6. Information retrieved from long-term memory by moving temporarily back to short-term memory
• Coding


  The way information is stored in memory stores
• Coding in memory stores

  • Sensory - iconic/echoic
  • Short-term memory - acoustic
  • Long-term memory - semantic
• Baddeley (1966) research on coding

  1. Aim: To test coding of short-term and long-term memory

  2. Procedure: 4 groups given lists of words to recall, with words varying in acoustic or semantic similarity

  3. Findings: Acoustically similar words harder to recall from short-term memory, semantically similar words harder to recall from long-term memory

  4. Conclusion: Short-term memory codes information acoustically, long-term memory codes information semantically
• Capacity


  The amount of information that can be held in a memory store
• Capacity of memory stores

  • Sensory - large
  • Short-term memory - 7 +/- 2
  • Long-term memory - unlimited
• Jacobs (1887) research on short-term memory capacity

  1. Aim: To test capacity of short-term memory using 'digit spans'

  2. Procedure: Researcher read out digit sequences, increasing length, participants recalled in order

  3. Findings: Mean digit span of 9.3 for digits, 7.3 for letters
• Miller (1956)


  Confirmed Jacobs' findings, created the 'magic number' of 7 +/- 2 to describe short-term memory capacity
• Duration


  The length of time information can be held in a memory store
• Duration of memory stores

  • Sensory - milliseconds
  • Short-term memory - up to 30 seconds
  • Long-term memory - infinite
• Peterson and Peterson (1956) research on short-term memory duration

  1. Aim: To examine duration of short-term memory

  2. Procedure: Participants given a trigram, counted backwards, recalled trigram at 3, 6, 9, 12, 15, 18 seconds

  3. Results: 80% could recall after 3 seconds, 3% after 18 seconds

  4. Conclusion: Short-term memory has limited duration
• Bahrick et al (1975) research on long-term memory duration


  1. Aim: To test duration of long-term memory

  2. Procedure: 392 participants aged 17-74, photo recognition and free recall of high school classmates

  3. Results: Within 15 years, 90% could do photo recognition, 60% free recall; within 48 years, 70% photo recognition, 30% free recall
• Multi-store model of memory

  • Supported by case study of HM, who had hippocampus removed and could not form new long-term memories
  • Supported by research showing different qualities of short-term and long-term memory (Baddeley)
  • Supported by serial position effect research (Murdoch)
• Criticisms of multi-store model:
• Tulving's three types of long-term memory

  • Episodic - memories of personal experiences, time-stamped
  • Semantic - memory of facts and knowledge
  • Procedural - memory of skills and actions
• Case study of Clive Wearing supports Tulving's model, showing impaired episodic memory but intact semantic and procedural memory
• Neuroimaging evidence supports Tulving's model, showing different brain regions involved in episodic and semantic memory
• Real-life applications of Tulving's model, e.g. targeted treatment of memory disorders
• Baddeley and Hitch's working memory model


  • Criticises multi-store model for suggesting memory stores are single units
  • Shows short-term memory is organised into central executive, visuo-spatial sketchpad, phonological loop, and episodic buffer
• Central executive


  • Main controller, directs attention and allocates information to other functions
  • Has limited capacity
• Visuo-spatial sketchpad


  • Temporary store for visual and spatial information, capacity of 3-4 objects
• Phonological loop


  • Deals with auditory information, has phonological store and articulatory control system
• Episodic buffer


  • Temporary store that integrates information from other stores, links central executive to long-term memory, capacity of 4 chunks
• Case study of KF supports working memory model, showing impaired short-term memory but intact long-term memory
• Dual task performance research supports working memory model, showing different components can be used simultaneously
• Criticisms of working memory model include lack of clarity about central executive, and need to separate visual and spatial components
• Interference


  Where memory can be interfered with by previous or future learning
• Types of interference


  • Proactive interference - old learning affects recall of new information
  • Retroactive interference - new learning affects recall of old information
• McGeoch and McDonald (1931) study on retroactive interference


  1. Procedure: Participants learned an initial list, then learned new lists with varying similarity

  2. Findings: More similar new lists caused greater retroactive interference and poorer recall of initial list
• Retroactive interference


  • New learning affects the recall of old information
  • Where later learning interferes with earlier learning
  • E.g., not being able to remember your old address because of your new address
• McGeoch and McDonald (1931) study on retroactive interference

  1. Participants learned a list of 10 words until they could remember them with 100% accuracy

  2. They then learned a new list

  3. There were 6 groups who learned different types of new lists
• Types of new lists learned by participants


  • Synonyms (words with the same meanings as the originals)
  • Antonyms (words with the opposite meanings to the originals)
  • Words unrelated to the original ones
  • Constant syllables
  • Three-digit numbers
  • No new list (control condition)
• In conditions where the new lists of words were the synonyms to the original list, recall of the list was worse
• Retrieval failure - encoding specificity principle


  • A cue (if going to be helpful) must be present at encoding and be present at retrieval
  • If this doesn't happen there will be some forgetting
  • Some cues are encoded at the time of learning in a meaningful way
• Retrieval failure


  When information is placed in the memory, associated cues are stored at the same time. If these cues are not available at the time of recall, then the associated memories cannot be accessed
• Types of retrieval failure

  • State dependent forgetting
  • Context dependent forgetting
• State dependent forgetting


  When internal cues that were present at the time of learning are now absent
• Context dependent forgetting


  When external environmental cues that were present at the time of learning are now absent
• Eyewitness testimony (EWT)


  The ability of people to remember the details of an event, such as a crime, which they have observed