Research into STM duration

• Peterson and Peterson conducted research into durationof STM

  -they presented ppts with a trigram and then were asked to count backwards for diff intervals PREVENTING REHERSAL

  -the retention intervals between recall varied in length from 3-18 secs

  -ppts were 24 uni students
• they found and concluded

  -that as the retention interval increased the % of trigrams correctly recalled decreased

  -that STM duration is 18-30 secs
• A weakness is that the stimuli are meaningless and the task is artificial

  -bc counting backwards while remembering letters is not an everyday task

  -lacks mundane realism and ecological validity
• Another weakness is that one could argue the memory trace has spontaneously disappeared without rehearsal

  -it may have been displaced by counting backwards

  -therefore the study may lack internal validity

  -more recent studies e.g Nairne et al (1999) found items could be recalled after 96 secs