1. coding, capacity, duration Flashcards
define CODING
the format in which information is stored in the various memory stores.
RESEARCH ON CODING
Baddeley gave different lists of words to 4 groups of participants to remember:
Group 1: acoustically similar words e.g. cat, can, cab
Group 2: acoustically dissimilar words e.g. bad, pit, cow
Group 3: semantically similar words e.g. great, big, large
Group 4: semantically dissimilar words e.g. good, hot, huge
BADDELEY - PROCEDURE
Participants were shown the words and asked to recall them in the correct order. When they did this task immediately (recall from STM), they tended to do worse with
acoustically similar words
RESEARCH ON CODING
When they recalled the word list after a time interval of 20 minutes (recalling from LTM), they did worse with
These findings suggest
semantically similar words.
that information is coded acoustically in STM and semantically in LTM.
RESEARCH ON CODING
AO3: strength of coding research
identified 2 separate stores, led to MSM
Baddeley’s study identified a clear difference between two memory stores.
Later research showed there is some exceptions to Baddeley’s findings, but the idea that STM uses mostly acoustic coding and LTM uses mostly semantic coding has stood the test of time.
This is a strength because this was an important step in our understanding of the memory system, which led to the multi store model.
RESEARCH ON CODING
AO3: limitation of coding research
artificial stimuli
Baddeley’s study used artificial material rather than meaningful stimuli.
The word lists had no personal meaning to the participants, so Baddeley’s findings may not tell us much about coding in different kinds of memory tasks, especially in everyday life. When processing more meaningful information, people may use semantic coding for STM tasks.
This suggests that these findings from this study have limited real life application.
define CAPACITY
the amount of information that can be held in a memory store.
CAPACITY STUDIES - STM ONLY
Jacobs measured participants digit span by
reading out digits and asked them to recall out loud. If they recalled correctly, one more digit would be out until failure. This determines the individual’s digit span.
CAPACITY STUDIES - STM ONLY
Jacobs found:
mean span for digits and letters
that the mean span for digits was 9.3 and letters was 7.3.
CAPACITY STUDIES - STM ONLY
Miller noticed that things come in 7s, e.g. 7 days of the week, 7 deadly sins.
Miller thought that the capacity of STM is
about 7 items plus or minus 2.
CAPACITY STUDIES - STM ONLY
Miller also noted that people can easily recall 5 words as well as letters - this is done by
(define chunking)
chunking, grouping sets of letters or digits into units or chunks.
CAPACITY STUDIES - STM ONLY
AO3: strength of coding research
Jacobs - replication
Jacobs’ study has been replicated.
This is a very old study and early research in psychology often lacked adequate control, e.g. some participants digit spans might have been underestimated due to confounding variables such as noise that provided distraction. Despite this, Jacobs’ findings have been confirmed by other controlled studies since.
This means that Jacobs’ study is a valid test of digit span in STM.
CAPACITY STUDIES - STM ONLY
AO3: limitation of coding research
Miller - less chunks? (Cowan)
Miller may have overestimated the capacity of STM.
Cowan reviewed other research and concluded that. The capacity of STM is 4 plus or minus 1 chunk.
This suggests that the lower end of Miller’s estimate (five items) is more appropriate than seven items.
DURATION STUDIES - STM
Peterson & Peterson
Procedure
tested 24 students in 8 trials each. Students were given a consonant trigram (e.g. YGZ) to remember and a 3-digit number to count backwards from to prevent any mental rehearsal of the trigram.
They were told to stop at varying periods of time e.g. 3,6,9,12,15,18 seconds.
DURATION STUDIES - STM
Peterson & Peterson
findings & conclusion
⭐️ 3 seconds: 80% correct / 6 seconds: 50% correct / 18 seconds: less than 3% correct.
⭐️ Duration of STM = 18 seconds unless information is repeated over and over.
DURATION STUDIES - STM
AO3: limitation of DURATION research
artificial stimulus
Peterson and Peterson’s study used artificial stimulus material.
The study is not completely irrelevant as we do remember meaningless things like phone numbers. Even so, recalling consonant syllables does not reflect most everyday memory activities where what we try to remember is meaningful.
This means their study lacked external validity.
DURATION STUDIES - LTM
Bahrick et al.
Procedure
studied 392 American participants aged 17-74. high school yearbooks were obtained, and they were tested on their memory of the names of their friends through:
photo recognition
free recall
DURATION STUDIES - LTM
Bahrick et al.
findings and conclusion
PHOTO RECOGNITION:
15 YEARS - 90% ACCURATE
48 YEARS - 70% ACCURATE
FREE RECALL: 15 YEARS - 60% ACCURATE
48 YEARS - 30% ACCURATE
⭐️ LTM LASTS UP TO A LIFETIME.
DURATION STUDIES - LTM
AO3: strength of DURATION research
meaningful memories
Bahrick’s study has high external validity.
This is because the researchers investigated meaningful memories. When studies of LTM were conducted with meaningless pictures to be remembered, recall rated were lower.
This suggests that Bahrick’s findings reflect a more real estimate of the duration of LTM.
