peterson and peterson 1959

• aim

  to investigate duration of short term memory
• a lab experiment was conducted in which 24 participants (psychology students) had to recall trigrams (meaningless three consonant syllables)
• brown peterson techniques

  to prevent rehearsal participants were asked to count backwards in threes or fours from specified number until they saw red light appear
• participants were asked to recall trigrams after intervals of 3, 6,9, 12, 15 or 18 seconds
• findings

  the longer the interval delay, the less trigrams recalled
• findings

  participants were able to recall 80% of trigrams after a 3 second delay. after 18 seconds less than 10% of trigrams recalled correctly
• conclusion

  stm has limited duration when rehearsal is prevented. it is thought that information is lost from short term memory from trace decay
• the results of study show stm is different from ltm in terms of duration, thus supporting the multi store model