Coding, Capacity and Duration of Memory

Question 1

Coding

Answer 1

Format in which information is stored in the various memory stores

Question 2

Capacity

Answer 2

Amount of information that can be held in a memory store

Question 3

Duration

Answer 3

Length of time information is held in memory

Question 4

Short-term memory (STM)

Answer 4

• Coding = Acoustically
• Capacity = 5-9 items on average
• Duration = 18-30 seconds

Question 5

Long-term memory (LTM)

Answer 5

• Coding = Semantically (meaning)
• Capacity = Unlimited
• Duration = Forever

Question 6

Alan Baddeley coding experiment - (1966)

Answer 6

• Gave different lists of words to four groups of participants to remember - (Acoustically similar, acoustically dissimilar, semantically similar, semanticaly dissimilar)
• Participants were shown the original words and asked to recall them in the correct order.
  When they had to immediately recall (STM recall), they tended to do worse with acoustically similar words.
• If participants were asked to recall after 20 minutes (LTM recall), they did worse with semantically similar words. This suggests information is coded semantically in LTM.

Question 7

Joseph Jacobs capacity experiment - (1887)

Answer 7

• Developed a technique to measure digit span.
• Researcher gives participant ,e.g., 4 digits to recall in correct order.
• If this was done correctly, the researcher will give the pp 5 digits, then 6, so on until they couldn’t recall anymore in the correct order. This determines the individual’s digit span.
• Jacobs found the mean span was 9.3 items across all pps. The mean span for letters was 7.3 items.

Question 8

George Miller duration experiment - (1956)

Answer 8

• Made observations of everyday practice. E.g. he noted things that came in sevens.
• E.g. 7 musical notes, 7 days of the week, and so on.
• This suggests span/capacity of the STM was around 7±2 items.
• Miller also noted people can remember 5 digits as well as they can remember 5 letters. They do this by chunking.

Question 9

Peterson and Peterson duration in STM experiment

Answer 9

• Pps were given a nonsense trigram. E.g. XHF.
• Immediately after seeing the trigram, they were given a three digit number, e.g. 346, and asked to count backwards in threes (e.g. 343,340,337…). This was done to prevent rehearsal.
• After a set delay (3,6,9,12,15 or 18 seconds), pps were asked to recall the trigram.
• Researchers found at 3 seconds, recall was around 80%. At 6 seconds, recall was around 50% and at around 18 seconds, recall was almost 0%.