A01 Coding, Capacity And Duration Of Memory

• Research on Coding

  Once information gets into memory , it is sorted into different formats depending on the memory store. Coding is a process of converting information from one form to another
• Baddeley


  Gave different list of words to 4 groups to remember: G1= Acoustically similar words- words that sound similar G2= Acoustically different words- words that sound different G3= Semantically similar words- words that have similar meaning, G4= Semantically different words- words that have dissimilar words,
• Task of Baddeley's experiment

  Ppts were asked to recall the original cards in the correct order
• Findings of Baddeley's experiment

  In short term memory recall, ppts did worse with acoustically similar words and in long term memory, ppts did worse with semantically similar words suggesting info is coded semantically in LTM.
• Research on capacity - Digit span

  Jacobs developed a technique to measure digit span: researcher gives ppt 4 digits and ppt told to recall the numbers in correct order out loud. If they succeed, give ppt a 5 digit number and test them- keep doing this until failure
• Jacob's findings

  The mean span for digits across all ppts was 9.3 items and mean span for letters was 7.3
• Span of memory and chunking

  Miller made observations of everyday practice and found that things come in 7s: 7 days in a week for example. Suggests that span of STM is 7 items +/- 2. Also, Miller suggested people can recall 5 words through chunking.
• Chunking


  Grouping sets of letters/digits
• Research on duration of STM

  Peterson and Peterson tested 24 undergraduate students who each took part in 8 trials. Each trial the student was given a consonant syllable/trigram (e.g. YGC) to remember. They were also shown a 3 digit number.
• Counting backwards

  Ppts told to count backwards as this prevented memory rehearsal which would have increased the memory of ppts and reduce validity of experiment
• Ppts stopping

  Each trial, ppts were told to stop at different times - 3,6,9,12,15 and 18.

  - Retention intervals
• Findings from Peterson and Peterson experiment

  STM- very short duration and found that STM goes up to 18 seconds. If the STM is constantly repeated however, the duration of memory increases
• Duration of LTM

  Bahrick et al used 392 ppts from Ohio aged 17-74 and measured the memory of the ppts from their graduation year books.
• Bahrick et al's procedure

  Obtained yearbooks from either ppts or school directly and did various testing:1)Photo-recognition of 50 pictures with some being from ppts high school2)Free recall test where ppts recalled all of the names in their class
• Findings of Bahrick's experiment

  Ppts tested within 15 years of graduation were 90% accurate while ppts tested within 48 years were 70%. For free recall, ppts within 15 years of graduating were 60% accurate and ppts within 48 years were 30% accurate- shows LTM can last a long time