CAPACITY, DURATION AND CODING

• What is memory?


  The process by which we retrieve and retain information from the past.
• What are the two types of memory?

  Short-term memory and long-term memory.
• What is coding?


  The way information is processed into memories.
• What is storage?


  The ability to retain information. Has limited duration and capacity.
• What is retrieval?


  Assessing information stored in memory.
• What is capacity?


  The amount we can store.
• What is duration?


  The length of time we can store.
• What is coding/encoding?


  The way information is processed by the store.
• Coding in short term = 7+/-2

  Coding in long term = unlimited
• Duration in short term = 18-30 seconds

  Duration in long term = unlimited
• Coding in short term = acoustically

  Coding in long term = semantically
• Research for STM duration:

  Peterson and Peterson (1959)- consonant trigram

  Asked to recall the trigram of 3 letters after counting backwards in threes to prevent rehearsal after 3, 6, 9, 12 seconds etc.

  Highest level of real was after 3 seconds (90%) but this decreased rapidly - 2% after 18 seconds.
• Research for STM capacity:


  Miller (1956) - digit span technique

  reading a series of digit sets that get gradually longer. participant is asked to repeat set immediately in the right order
• Research for LTM duration:

  Bahrick et al (1975) - asked 392 17-74 year olds to name old classmates from high school photos(free recall); given 50 photos and asked if they remember their classmates (recognition)

  Found that 25 years after graduation, free recall was 60% accurate. after 48 years this dropped to 30%

  Recognition was 90% after 25 years, dropping to 70% after 48 years.
• Research for STM coding:


  Baddeley (1966) - present list of words that were acoustically similar and asked for immediate recall.

  Made more errors than if they were presented with acoustically different words

  Confusion based on sound.
• Research for LTM coding:

  Baddeley (1966) - presented words that were semantically similar and asked for recall 20 mins later

  Made more errors than when they were presented with semantically different words

  Confusion over meaning of words