Memory

• Who tested digit span?

  Jacobs
• Digit span procedure 


  Researcher reads digit span eg 4 numbers, and participants recall them
• Digit span


  9.3 items
• Span for letters


  7.3
• Who investigated STM capacity?

  Miller
• STM Capacity


  7 +/- 2 items Can be increased by chunking units of info
• Who investigated STM duration?

  Peterston and Peterson
• How did Peterson and Peterson test STM duration? 


  Using trigrams (3 letters)

  Told trigrams, rehearsal was prevented and after memory retention intervals of 3, 6, 9, 12, 15 or 18 seconds, ppts were asked to repeat them
• STM duration 


  18-30 seconds
• Peterson and Peterson found that after 18 seconds only 3% of participants could recall the trigram
• Who investigated LTM duration?

  Bahrick
• How was LTM duration tested?

  Bahrick asked participants to recall names of people from their high school in a free recall test (no prompts), then with a photo-recognition test where only some photos were of old classmates, then with a name recognition test by selecting classmates out of a list of names

  After 48 years free recall had 30% accuracy - LTM may be lifetime (+ppts better at photo recognition so photos/reminders can trigger memories)
• LTM duration

  Up to a lifetime
• Who investigated memory coding?

  Baddeley (ofc)
• How is STM coded?

  Acoustically
• How is LTM coded?

  Semantically
• Baddeley LTM Coding Procedure

  Participants in 4 groups

  Shown 10 words on slideshow

  1. Acoustically similar (experimental)
  2. Acoustically dissimilar (control)
  3. Semantically similar (experimental)
  4. Semantically dissimilar (control)

  Participants carried out interference test to distract them then asked to recall words
• Baddeley Coding Experiment Results

  Acoustic conditions: Control and experimental groups had similar results

  Semantic conditions: Control group outperformed experimental group suggesting LTM becomes confused with similar word meanings

  Therefore LTM is semantically coded
• Baddeley Coding Evaluation


  Lab study

  Lacks generalisability due to individual differences and population bias (Cambridge Uni students used)

  Uses artificial tools so lacks ecological validity
• Capacity Experiment Evaluation


  Chunking has ecological validity (phone numbers)

  Lab studies

  Artificial tools
• Duration Research Evaluation


  Lab study

  Bahrick had ecological validity

  P&P used artificial tools
• Multi-Store Model


  Developed by Atkinson and Shiffrin

  
• Sensory Register Duration 


  250ms
• Sensory Register Coding 


  Sensory modality
• How do memories move from STM to LTM?

  Prolonged rehearsal
• How do memories move from LTM to STM?

  Retrieval
• What is the fancy MSM word for forgetting?

  Memory decay
• What is the fancy MSM word for remembering? (not retrieval)

  Output response
• How do memories stay in the STM?

  Maintenance rehearsal
• Sensory Register Stores


  Iconic (visual)

  Echoic (auditory)

  + Others
• Who investigated serial position?

  Murdock
• How did Murdock investigate serial position?


  Ppts asked to learn list of words and free recall them

  He found probability of remembering word depended on its position in list

  More likely to remember start (primacy effect) or end (recency effect) of list

  This is because first words are rehearsed long enough to enter LTM, and last words are still in STM
• Primacy effect


  Remembering first words in list due to rehearsal and entering LTM
• Recency effect


  Remembering last words in list due to STM
• Serial Position Definition


  Word's position in list
• HM


  Section of his brain was removed including parts of hippocampus

  He lost the ability to form new memories but had good STM

  No amount of prolonged rehearsal transferred new things to LTM

  Suggests STM and LTM in different stores
• KF


  Patient with brain damage studied by Shallice and Warrington

  Had good LTM bur damaged STM

  Visual digit span performance better than auditory

  Suggests two types of STM - visual and auditory stores seperate
• MSM Evaluation 


  Serial Position Effect supporting evidence

  HM supporting evidence

  KF contrasting evidence -suggests multiple types of STM

  Artificial tools used in testing
• Who created the working memory model?

  Baddeley and Hitch
• Parts of Working Memory Model

  Central Executive

  Visuo-spatial sketchpad

  Episodic Buffer

  Phonological loop

  Long term memory