DURATION

• what is duration?

  how long the memory lasts before it is no longer accessible
• What is the duration of STM?

  Less than 30 seconds. usually 18
• What is the duration of LTM?

  Potentially unlimited
• Who investigates the duration of STM?

  Peterson and Peterson
• Who investigates the duration of LTM?

  Bahrick et al
• How did Peterson and Peterson investigate duration?

  Consonant Syllables ( Trigrams)

  24 students were given a trigram to recall and a number to count backwards from. The time counting varied from 3 to 18 seconds
• What were the findings of Peterson and Petersons trigrams?

  after 3 seconds average recall was 80%

  after 18 seconds it was 3%

  STM duration without rehearsal is up to 18 seconds
• How did Bahrick investigate LTM?

  Yearbook photos

  392 Americans ages between 17 and 74

  Recognition test - 50 photos from their high school yearbooks

  Free Recall Test - participants listed names of their class
• What were the findings of Bahricks experiment?

  recognition test - 90% were accurate after 15 years, 70% after 48

  Free recall test - 60% recall after 15 years, 30% after 48 years
• What were the findings of Bahricks experiment?

  recognition test - 90% were accurate after 15 years, 70% after 48

  Free recall test - 60% recall after 15 years, 30% after 48 years