Short- and long-term memory Flashcards
What is capacity?
Measure of how much can be held in memory. How many ‘bits’ of information.
What is duration?
How long a memory last before it is no longer available.
What is coding?
The way in which information is changed so that it can be stored in memory.
What is the capacity of STM?
7±2 letters/digits/chunks.
Who researched capacity of STM?
Miller
What was Miller’s research into capacity of STM?
Found that participants could remember 7 dots flashed onto a screen but not many more. Also reviewed previous research into the area. Published famous “magic number 7 plus or minus 2” paper.
(AO3) Why can we recall words as well as we can recall letters?
‘Chunking’ pieces of information together. Remembering patterns, chunks of numbers etc. Size of chunk does matter. Shows STM is more complex than 7±2.
(AO3) How do individual differences effect STM?
(Apparently) random differences in STM capacity. Also affected by factors such as age - recall increases with age up to a point. Intelligence, attention, development of brain.
What is the capacity of LTM?
Supposedly infinite. Almost impossible to research.
Who investigated the duration of STM?
Peterson and Peterson.
How did Peterson and Peterson investigate duration of STM?
Participants given 3 consonants and 3 digit number (THX 236). Asked to recall consonants after interval of 3-18 seconds. Had to count back from number during interval to prevent maintenance rehearsal.
What did they find about the duration of STM?
90% correct after 3s. 20% after 9s. 2% after 18s.
Suggests STM duration <18s (very short)
Who tested duration of LTM?
Bahrick et al.
How did Bahrick et al. test duration of LTM?
400 participants of various adult ages given photos from high school yearbook. Asked to recall as many names as possible.
What did Bahrick et al. find about duration of LTM?
90% accurate within 15 years of graduation. 70% after 48 years.
