Lesson 2: Coding, Capacity, and Duration Flashcards
How does coding work in the Sensory Register?
It is modality specific - each sensory store codes information differently
What did Baddeley’s 1966 study of coding involve?
- investiagted both STM and LTM
- participants had 4 lists of words to recall:
A - similar sounds
B - dissimilar sounds
C - similar meaning
D - dissimilar meaning - for LTM, participants waited 20 minutes before recalling lists
What were Baddeley’s conclusions about STM?
- coded acoustically
- worse performance with list A than B
- no difference in lists C and D
- STM organises information according to how it sounds
What were Baddeley’s conclusions about LTM?
- coded semantically
- no difference in lists A and B
- worse performance with list C than D
- LTM organises information according to its meaning
Evaluate Baddeley’s 1966 study.
(+) Laboratory experience - easy to replicate as variables are controlled, reliability can be assessed
(-) Low ecological validity - lists were artificial unlike what information might need to be recalled in real life
What is the capacity of the Sensory Register?
Unlimited
What is the capacity of STM?
7 (+/-) 2 items
How did Jacobs (1887) determine the capacity of STM?
- Digit Span Test
- participants given several sequences of digits/letters
- asked to repeat in the correct order
- sequences increased by one item each time
What were the results from Jacobs’ 1887 study?
- avg items we hold: 9.3 digits and 7.3 letters
What did Miller (1956) do/find?
- reviewed psychological studies
- concluded that span of STM is 7 (+/-) 2
- old information gets displaced
- chunking helps us remember more
Evaluate Jacobs’ 1887 study.
(+) first to acknowledge that STM capacity gradually improves with age
(-) Lack temporal validity - conducted in 1887
What is the capacity of LTM?
Unlimited
What is the duration of the SR?
250 milliseconds
How did Peterson and Peterson (1959) determine the duration of STM?
- Nonsense Trigram’s (three random consonants)
- participants asked to count back in 3s from 100 to avoid rehearsal maintenance
What were the results from Peterson and Peterson’s (1959) study?
- recall was accurate: 90% after 3s 20% after 9s 2% after 18s - information lasts in STM for 18 - 30s before being lost due to decay
Evaluate Peterson and Peterson’s (1959) study.
(+) High level of control of extraneous variables, using standardised procedures
(-) findings could be due to interference - earlier trigrams confused with later ones
What is the duration of LTM?
Potentially a lifetime (unknown)
How did Bahrick (1979) determine the duration of LTM?
- tested 400 people (17-74yrs) on memory of classmates
- photo recognition test; participants shown 50 photos and decided if they were a classmate
- free recall test; asked to list classmate names
What were the results from Bahrick’s (1979) photo recognition test?
- identification of faces was accurate:
90% within 15yrs
70% within 48yrs
What were the results from Bahrick’s (1979) free recall test?
- identification of names was accurate:
60% within 15yrs
30% within 48yrs
What were the conclusions of Bahrick’s (1979) study?
- LTM duration is potentially a lifetime
- we have retrieval failure
- may need retrieval cues to access information
Evaluate Bahrick’s (1979) study.
(+) High ecological validity compared to Peterson and Peterson (1959)
(-) low control of extraneous variables - ie people staying in contact after graduating
What is the duration of STM?
18 - 30 seconds
