Coding, Capacity And Duration Of Memory Flashcards
Baddeley’s study
What year?
1996
Baddeley’s study
Name of study?
Coding in STM and LTM
Baddeley’s study
Procedure?
Asked participants to learn a list of acoustically similar words (e.g. Cat, bat) or a list of dissimilar words (e.g. Cat, dog)
Asked participants to learn a list of semantically similar words (e.g. Large, big) or a list of dissimilar words (e.g. Large, yellow)
Baddeley’s study
Findings and conclusions?
Immediate recall worse with acoustically similar words, STM is acoustic.
Recall after 20 mins worse with semantically dissimilar words, LTM is semantic.
Jacobs’ study
Year?
1887
Jacobs’ study
Name of study?
Capacity of STM
Jacobs’ study
Procedure?
Digit span: researcher reads four digits and increases until the participants cannot recall the order correctly.
Jacobs’ study
Findings?
On average participants could repeat back 9.3 numbers and 7.3 letters in the correct order immediately after they were presented.
Baddeley’s study
Limitation?
- didn’t use meaningful material - can’t generalise findings - people may use semantic coding for more meaningful tasks
- only 20 mins for long term memory
Jacobs’ study
Limitation?
It was conducted a long time ago - early researcher often lacked adequate control of extraneous variables - participants could have been distracted? - results would be because confounding variables were not controlled - however results have been confirmed in other experiments supporting the validity
Miller’s study
Year?
1956
Miller’s study
Name of study?
Capacity of STM
Miller’s study
Procedure?
Noticed that lots of everyday things come in sevens e.g. Seven notes in a scale, seven days in a week etc
Miller’s study
Findings
The span of STM is about seven items (+/- 2) but can be improved by chunking
Miller’s study
Limitation?
It may have overestimated the capacity of the STM - Cowan (2004) reviewed other research and concluded that the STM capacity was more likely to be about 4 chunks - lower end of millers estimation (5) is more likely than seven
Peterson and Peterson’s study
Year?
1959
Peterson and Peterson’s study
Name of study?
Duration of STM
Peterson and Peterson’s study
Procedure?
24 students were given a consonant syllable (e.g. YCG) to remember and a three digit number to count backwards for 3, 6, 9, 12, 15 or 18 seconds.
Peterson and Peterson’s study
Findings?
Students recalled on average about 80% of the syllables correctly with a three second interval. Average after 18 seconds fell to 3%.
The duration of the STM must be about 18-30 seconds
Peterson and Peterson’s study
A limitation?
The stimulus is artificial - not everyday activity- lacks external validity - however sometimes we do need to remember irrelevant things like phone numbers
Bahrick et al.’s study
Year?
1975
Bahrick et al.’s study
Name of study?
Duration of LTM
Bahrick et al.’s study
Procedure?
392 American participants aged between 17 and 74
- Recognition test - 50 photos from participants high school year book
- Free recall test - participants listed names of their graduating class
Bahrick et al.’s study
Findings
Participants tested 48 years after graduating were about 70% accurate in photo recognition. Free recall was less accurate.
Bahrick et al.’s study
Strength?
High external validity - something that would happen in real life - when lab tests were done with more meaningless photos recall rates were lower - BUT confounding variables cannot be controlled such as some participants may have looked at their yearbook more often than others
