Long & Short Term Memory Flashcards
What is the capacity for short term memory?
5-9 items
What is the duration for short term memory?
18-30 seconds
Whose study proves the duration of Short Term Memory?
Peterson & Peterson (1959)
What is the duration of Long Term Memory?
A lifetime
What is the capacity of Long Term Memory?
Unlimited/very large
Who tested the duration of Long Term Memory?
Bahrick et al (1975)
What did Peterson & Peterson do?
Asked 24 undergraduate students to remember consonant trigrams
Had to count back in 3s to prevent rehearsal
IMMEDIATELY said the words back
90% got it after 3 seconds
10% got it after 18 seconds
What is the evaluation of Peterson & Peterson’s experiment (1959)?
Good control of variables (lab experiment - IV manipulation & no EV)
Low ecological validity (don’t remember consonant trigrams in everyday life)
Duration of Short Term Memory may not be tested properly (earlier trigrams may cause confusion)
What did Bahrick et al do (1975) and find?
400 Americans tested on classmates memory
70% accuracy for linking names to faces - even after 48 years
30% accuracy with free recall
What is the evaluation for Bahrick et al (1975)?
Good ecological validity (remembering names is a meaningful task we do in everyday life)
Bad control of variables (some names may have been rehearsed if kept in touch)
Results can’t be applied to all information (only had to remember names of classmates)
Who tested the capacity of Short Term Memory?
Jacob (1887) - developed serial digit span technique
Miller (1956) - reviewed experiments into capacity
What did Jacobs (1887) do and find?
Read out 4 digits and asked participants to repeat back immediately
More digits added until participants couldn’t remember
9 digits and 7 letters recalled
Increases during childhood
What is the evaluation for Jacobs study (1887)?
It is repeatable - same results have been found in later studies
Low ecological validity - (don’t have to remember numbers & letters everyday)
Capacity of Short Term Memory may not have been tested properly - (previous sequences may cause confusion - confounding variable)
How is Short Term Memory coded?
Acoustically (sound)
What are the 3 types of coding?
Acoustic
Semantic
Visual
How is Long Term Memory coded?
Semantically
Who tested the coding of Short Term Memory & Long Term Memory?
Baddeley (1966)
What did Baddeley (1966) do and find?
Sequence of 5 words with 4 conditions (similar…)
When tested immediately participants struggled to remember the acoustically similar words
When tested after 20 minutes, participants least accurate with semantically similar words
What is the evaluation of Baddeley’s study (1966)?
Identifies clear differences in the coding of 2 memory stores - one is coded different to the other
Low ecological validity (meaningless list which has no value to participants)
