Memory - Coding, Capacity and Duration Flashcards
What is coding?
The format in which information is stored in various memory stores.
What is capacity?
The amount of information that can be held in each memory store.
What is duration?
The length of time information can be held in memory.
Who researched coding in the STM vs LTM?
Baddeley
How did Baddeley research coding in the STM vs LTM?
He gave different lists of words to 4 groups of participants to remember the order:
Group 1 - acoustically similar e.g cat, cab, can
Group 2 - acoustically dissimilar e.g. pit, few, cow
Group 3 - semantically similar e.g. great, large, big
Group 4 - semantically dissimilar e.g. good, huge, hot
What were Baddeley’s findings and conclusion in his research on coding in the STM vs LTM?
When participants recalled the word list order immediately (using the STM), they did worse with the acoustically similar words.
When participants recalled the word list order after 20 minutes (using the LTM), they did worse with the semantically similar words.
These findings suggest that information in the STM is coded acoustically and that information in the LTM is coded semantically.
Who researched capacity in the STM?
Miller (1956)
How did Miller research capacity in the STM and what were his findings and conclusions?
He made observations of everyday practice and found that many things come in 7s…seven notes on the musical scale, seven days of the week, seven deadly sins etc!
Miller thought that the capacity of the STM is about 7 items, plus or minus 2
Miller also found that we recall 5 words as easily as 5 letters by chunking information - grouping sets of digits or letters into units or chunks.
Who researched duration in the STM?
Peterson and Peterson (1959)
How did Peterson and Peterson research duration in the STM?
They tested 24 students in 8 trials each.
On each trial the student was given a trigram to remember and a 3 digit number to count backwards from until told to stop to prevent any mental rehearsal of the trigram.
On each trial they were told to stop counting at various intervals of time: 3, 6, 9, 12, 15 or 18 seconds (the retention interval)
What were Petersons and Petersons findings and conclusions in their research on duration in the STM?
After 3 seconds, average recall was 80%.
After 18 seconds, average recall was 3%.
These findings suggested that STM duration may be about 18 seconds, unless we repeat information over and over.
Who researched the duration of the LTM?
Bahrick (1975)
How did Bahrick research the duration of the LTM?
He studied 392 American participants between 17-74 and obtained their high school yearbooks.
Recall was tested in various ways:
1. Photo-recognition test, consisting of 50 photos, some from their yearbooks and some not, participants recalled which people they graduated with
2. Free recall test, participants recalled all the names of their graduating class
What was Bahrick’s findings and conclusions in his research on the duration of the LTM?
Participants tested within 15 years of graduation were about 90% accurate in photo recognition.
After 48 years, recall declined to about 70% in photo recognition.
Free recall was less accurate than photo recognition - about 60% after 15 years, dropping to 30% after 48 years.
These results show that the LTM may last a lifetime for some material such as face recognition.
Give a strength and limitation of Baddeley’s study on coding.
Strength - Led to the development of the multi-store model as it identified a difference between two memory stores
Limitation - The words used tell us little about coding for everyday memory tasks. When processing more meaningful info, people use semantic coding even for STM. This means the study has limited application due to its use of artificial stimuli.
