Coding, Capacity & Duration of Memory

• What is short term memory characterized as?

  The limited capacity memory store
• What is the main coding type for short term memory?

  Mainly acoustic
• What is the capacity range of short term memory?

  Between 5 - 9 objects
• What is the duration of short term memory?

  About 18 seconds
• What is long term memory characterized as?

  The permanent memory store
• What is the main coding type for long term memory?

  Mainly semantic
• What is the capacity of long term memory?

  Unlimited
• What is the duration of long term memory?

  For a lifetime
• What is encoding in memory?

  How information is processed into memory
• What did Baddeley (1966) investigate?

  The coding of short and long term memory
• What types of word lists did Baddeley use?

  Acoustically and semantically similar/dissimilar
• How were participants asked to recall the words in Baddeley’s (1966) study?

  In the order presented
• What was the recall method for short term memory in Baddeley's study?

  Recall immediately
• What was the recall method for long term memory in Baddeley's study?

  Recall after 20 minutes
• What did Baddeley find about acoustically similar words?

  Worst recall when asked immediately
• What was the result for semantically similar words in long term memory?

  Worst recall for long term memory
• How does short term memory encode information?

  Acoustically
• How does long term memory encode information?

  Semantically
• What did Baddeley's (1966) study contribute to memory research?

  • Identified differences between memory stores
  • Led to the multi-store model of memory
  • Suggested short term memory uses acoustic coding
  • Suggested long term memory uses semantic coding
• What is a limitation of Baddeley's (1966) study?

  Used artificial stimuli
• What did Jacobs (1887) measure?

  Digit span to investigate capacity
• What was the mean digit span found by Jacobs?

  9.3 items
• What was the mean letter span found by Jacobs?

  7.3 items
• What did Miller (1956) suggest about short term memory capacity?

  7 ±2 items
• What is chunking in memory?

  Grouping sets of digits or letters
• What are the strengths and weaknesses of Jacobs's (1887) study?

  Strengths:

  • Findings confirmed by better controlled studies
  • Valid test of digit span in short term memory

  
  

  Weaknesses:

  • Lacked adequate controls
  • Potential confounding variables
• What did Cowan (2001) conclude about short term memory capacity?

  Only 4 ±1 chunks
• What did Peterson & Peterson (1959) test?

  Duration of short term memory
• How many students were tested in Peterson & Peterson's study?

  24 students
• What task were participants given in Peterson & Peterson's study?

  Remember a consonant and count back
• What was the average recall after 3 seconds in Peterson & Peterson's study?

  About 80%
• What was the average recall after 18 seconds in Peterson & Peterson's study?

  About 3%
• What did Bahrick et al (1975) study?

  Duration of long term memory
• How many Americans were studied by Bahrick et al?

  392 Americans
• What age range did participants in Bahrick et al's study fall into?

  17 - 74 years
• What types of tests were used in Bahrick et al's study?

  Photo recognition and free recall tests
• What was the accuracy of participants within 15 years of graduation in photo recognition?

  Around 90% accurate
• What was the accuracy of participants after 48 years of graduation in free recall?

  Around 30% accurate
• What does Bahrick et al's study suggest about long term memory?

  May last for a lifetime
• What are the strengths and weaknesses of Bahrick et al's (1975) study?

  Strengths:

  • High ecological validity
  • Investigated meaningful memories

  
  

  Weaknesses:

  • Lower recall with meaningless pictures
  • Limited generalizability to artificial stimuli