Short term and long term memory Flashcards
what is STM
- limited capacity of 4 bits/ chunks
- referred to as the working memory model
- measured in seconds and minutes
- encoding acoustically
- memory for immediate events
- usually disappears if it is not rehearsed
- systems which provide retention of limited amounts of material for a limited time
what is LTM
- memory for events in the past
- ranges from 2 minutes to 100 years
- potentially unlimited capacity and duration
- encodes semantically
- refers to the retention of material for an unlimited duration
what is capacity?
a measure of how much can be held in memory, represented in bits of information such as digits.
what is duration?
How long a memory lasts before it is no longer available
what is coding?
How information is changed so that it can be stored and turned into memory
this can either be semantically, acoustically or visually
go into detail about capacity
George Miller in 1956 wrote an article called the magic number 7 plus or minus two
he believed that humans could only remember more or less than the title of his article
He said that if we were flashed seven dots we could only remember seven and not anymore
Joseph Jacobs in 1887 conducted an experiment called the digit span and found that mean digit span was 9.3 and the mean letter span was 7.3
He said that the reason this was so was due to the fact that there are 9 digits and 26 letters in the alphabet
go into detail about duration
Llyod Peterson and Magaret Peterson in 1959 conducted an experiment of 24 participants with 8 trials
they were given a consonant syllable/three digit number and were asked to repeat it after an retention interval of 3,6,9,12,15 and 18
They were then asked to repeat the 3 digit number backwards
(THX 512)
the results showed that 90% were correct after 3 seconds
20% were correct after 9 seconds
and 2% were correct after 18 seconds
Bahrick et al in 1975 conducted a study with 400 participants with an age range of 17-74
he tested them on their long term memory in relation to their high school yearbook with photo recognition and free recall
He found that after 15 years 90% could remember their names (photo recognition) and 70% could remember after 48 years
for the free recall, 60% could remember after 15 years and
30% could remember after 48 years
go into detail about coding
Baddely et al in 1966a and 1996 b had a word list of acoustically similar words and semantically similar words
he found that people struggled in relation to their short term memory with acoustically similar words and did not struggle in their long term memory and found that people struggled with semantically similar words in their short term memory and not their long term
