Short and long term memory Flashcards
(12 cards)
1
Q
How are LT and ST memory distinguished?
A
by their capacity, duration and coding
2
Q
What is the capacity for the LTM and STM?
A
- LTM: infinite
- STM: Limited
3
Q
What did Miller suggest about the capacity of STM?
A
- Typically people can remember between 5-9 items (Miller’s magic number)
- Span of immediate memory 7 +/- 2
- Same is true for letters and digits
4
Q
What did Jacobs find regarding the capacity of STM for digits and letters?
A
- Average span for digits was 9.3 items
- 7.3 for letters
- suggested easier for digits as there are 9, whereas there is 26 for letters
5
Q
Who carried out the study of duration into the STM?
A
Peterson and Peterson
6
Q
What did Peterson and Peterson do to study duration the STM?
A
- lab experiment
- 24 ppts had to recall trigrams (meaningless 3 consonant syllables)
- to prevent rehearsal ppts were asked to count backwards in 3’s or 4’s from a specific random number until they saw a red light appear
- ppts were asked to recall trigrams after intervals of 3,6,9,12,15 or 18 seconds
- found the longer the interval delay the less trigrams remembered
7
Q
How did Bahrick et al study the duration the LTM?
A
- tested 400 ppl (17-74) on memory of classmates
- photo recognition test (50 photos)
- ppts asked to list names
- ppts tested within 15 years showed 90% accuracy
- 48 years after showed 70% accuracy
- Free recall was 60% after 15 years and dropping to 30% after 48 years
8
Q
What did Baddeley suggest about the coding of the STM and LTM?
A
- STM: acoustically
- LTM: Semantically
9
Q
How did Baddeley come to the conclusions of the coding of the memory stores?
A
- Acoustically similar words are difficult to remember in the STM but not LTM
- Semantically similar words are difficult to remember in the LTM but not STM
10
Q
A03 - Capacity - Individual differences - Challenge
A
- Jacobs found recall (digit span) increased steadily with age
- 8 year olds average 6.6 digits
- 19 year olds average 8.6
- Age increase might be due to changes in the brain capacity and/or due to the development of strategies such as chunking
11
Q
A03 - Duration - Artificial tasks
A
- Tasks ppts are asked to carry out are artificial
- trying to memories consonant syllables not reflect most everyday memory activities, where we remember something meaningful
- However, we do remember meaningless things (phone number, post codes)
- Although task was artificial, it does have relevance to every day life
12
Q
A03 - Coding - Other ways information can be coded
A
- Brandimote et al
- ppts use visual coding in STM, if given visual tasks and prevented from any verbal rehearsal
- other research shown STM sometimes use semantic code (Wikens et al)
- suggests that STM is not exclusively acoustic
