The Nature of Memory

The Nature of Memory

1. Duration

   • STM
     • 20 seconds
     • Maintenance rehearsal keeps a memory in the STM
     • Short term memories eventually become long term memories
     • Peterson and Peterson (1959) used university participants. Experimented said nonsense-syllable followed by 3-digit number. Participant counted backwards, each time retention interval was increased. 3s = 90% and 18s = 2%.
   • LTM
     • 2hrs to 100 years
     • Bahrick et al. (1975) asked people to name the people in their high school year book. 48 years on, people were about 70% accurate

2. Capacity

   • STM
     • Less than 7 chunks
     • Miller (1956) reviewed research and concluded the maximum amount of chunks the STM can hold is 7.
   • LTM
     • Potentially unlimited

3. Encoding

   • STM
     • Acoustic and Visual
     • Baddeley (1966) gave participants word list that were acoustically similar or dissimilar and semantically similar or dissimilar. Acoustically similar words were difficult for STM and semantically similar words were difficult for LTM.
   • LTM
     • Semantic
     • Semantic