STM

• Procedure


  Margaret and Lloyd Peterson tested 24 students in eight trials each. Students were given a consonant syllable to remember, and a 3 digit number. They counted backwards from the number until told to stop to prevent mental rehearsal of the syllable. On each trial they were told to stop after varying periods of time; 3, 6, 9, 12, 15 and 18 seconds.
• Findings


  The findings were similar to the student data in the graph:

  • After 3 seconds, average recall was about 80%
  • After 18 seconds, average recall was about 3%
  • Peterson and Peterson's findings suggest that STM duration may be about 18 seconds without rehearsal