Memory

• What was the aim of Baddeley's (1966) study?


  To test coding of STM and LTM
• What procedure did Baddeley use in his study?


  • Gave different lists of words to four groups:

  1. Words sounding similar (acoustically)
  2. Words sounding different (acoustically)
  3. Words with similar meaning (semantically)
  4. Words with different meaning (semantically)

  • Participants recalled visual words in the same order
• What were the findings regarding immediate recall in Baddeley's study?


  Words with similar sounds were much harder to recall than words with dissimilar properties
• What were the findings regarding recall after 20 minutes in Baddeley's study?


  Words with similar meaning were much harder to recall
• What conclusion did Baddeley draw about STM and LTM coding?


  STM codes acoustically, while LTM codes semantically
• What does Baddeley's study suggest about the storage of STM and LTM?


  They use varying stores as they code differently
• What is a strength of Baddeley's study regarding memory stores?


  • Showed a clear difference between STM and LTM
  • Contributed to understanding of memory systems
  • Led to the development of the multi-store model
• What is a limitation of Baddeley's study regarding stimuli used?


  • Used artificial stimuli rather than meaningful
  • Word lists had no personal meaning
  • Findings may not apply to real-world memory tasks
• What was the aim of Jacobs' study?


  To test the capacity of STM
• What procedure did Jacobs use to measure STM capacity?


  • Participants repeated a sequence of digits back immediately
  • Repeated several times with increasing digit lengths
  • Stopped when participants made an error
• What was the mean digit span found in Jacobs' study?


  1. 3 for letters and 9.3 for digits
• What did Jacobs conclude about the capacity of STM?


  STM has a limited capacity between 5-9 items
• What is a strength of Jacobs' study regarding its replicability?


  • Jacobs' study has been replicated
  • Provides support for the findings
  • Early research lacked adequate controls
• What is a limitation of Jacobs' study regarding confounding variables?


  • Early research lacked adequate controls
  • Confounding variables may have affected results
  • Participants might have been distracted during testing
• What was the aim of Peterson & Peterson's study?


  To test the duration of STM
• What procedure did Peterson & Peterson use to test STM duration?


  • Participants presented with a 3-letter consonant syllable (trigram)
  • Asked to count backwards for intervals of 3, 6, 9, and 12 seconds
  • Prevented rehearsal during the task
• What were the findings regarding recall after 3 seconds in Peterson & Peterson's study?


  Average recall was 80%
• What were the findings regarding recall after 18 seconds in Peterson & Peterson's study?


  Average recall was 3%
• What conclusion did Peterson & Peterson draw about the duration of STM?


  STM has a duration of approximately 18-30 seconds when rehearsal is prevented
• What is a limitation of Peterson & Peterson's study regarding the material used?


  • Used meaningless material (trigrams)
  • Lacks external validity
  • Does not reflect typical memory tasks
• What was the aim of Bahrick et al.'s study?


  To test the duration of LTM
• What method did Bahrick et al. use to test LTM duration?


  • Showed high school yearbooks
  • Tested recall through:

  1. Photo recognition test of 50 yearbooks
  2. Free recall of names from graduating class
• What were the findings for photo recognition after 15 years in Bahrick et al.'s study?


  90% accurate
• What were the findings for free recall after 48 years in Bahrick et al.'s study?


  30% accurate
• What conclusion did Bahrick et al. draw about the duration of LTM?


  LTM may last up to a lifetime for recall material
• What is a strength of Bahrick et al.'s study regarding external validity?


  • High external validity
  • Investigated meaningful memories
  • Findings represent a more realistic estimate of LTM duration
• What was the aim of Miller's 1956 study?


  To test the capacity of short-term memory (STM)
• What did Miller find regarding the capacity of STM?


  The capacity of STM is 7 ± 2 items
• How many words can people recall as easily as letters according to Miller's findings?


  People can recall 5 words as easily as 5 letters
• What is referred to as Miller's Magic Number?


  Miller's Magic Number is 7 ± 2
• What is a limitation of Miller's research on STM capacity?


  • May have underestimated STM capacity
  • Research conducted by Nelson Chean reviewed other studies
  • Peak capacity of STM is about 4.5 chunks
  • Suggests lower end of Miller's estimate (5 items) is more appropriate
• What does the peak capacity of STM being about 4.5 chunks imply about Miller's findings?


  It suggests that the lower end of Miller's estimate (5 items) is more appropriate than 7 items
• What is the multi-store model of memory proposed by Atkinson and Shiffrin?


  A model that assumes different types of memory exist
• What does the multi-store model of memory suggest about the system's operation?


  The system works effectively and follows a linear path
• What are the key features of the multi-store model of memory (MSM)?


  • A structural model
  • Distinction between SR, STM, and LTM
  • Damage to one store does not affect others
  • Information passes linearly (SR → STM → LTM)
  • Each store has different characteristics (coding, capacity, duration)
  • Different explanations for forgetting in each store
• What is the capacity of the sensory register (SR)?


  Very large
• What is the duration of the sensory register (SR)?


  Milliseconds
• What type of coding is used in the sensory register (SR)?


  Iconic/Echoic
• What is the duration of short-term memory (STM)?


  Max 30 seconds
• What is the capacity of short-term memory (STM)?


  7 +/- 2 items