Peterson and Peterson STM Duration rehearsal loop

• Who were the experimenters?

  Lloyd Peterson and Margaret Peterson
• What was the aim of this experiment?

  see how long STM lasts when rehearsal is prevented
• What was the method used?

  prevention of STM rehearsal was a distractor task

  the student has to recall meaningless 3 letter trigrams at different intervals and count backwards in 3s or 4s from as specific number as the distractor task
• what was the distractor task?


  count backwards in 3s or 4s
• Who were the participants in this experiment?


  24 psychology students
• What research method was used?


  laboratory experiment
• What were the findings?


  longer interval = less accurate recall

  at 3 seconds 80% accurate recall

  at 18 seconds only 10% accurate recall
• What were the results?

  if we are unable to rehearsed information it will not be passed into LTM
• What was the evaluation?


  psychology students may use demand characteristics and memory techniques

  low ecological validity, highly controlled lab experiment