Lesson 2: Coding, Capacity, and Duration

Question 1

How does coding work in the Sensory Register?

Answer 1

It is modality specific - each sensory store codes information differently

Question 2

What did Baddeley’s 1966 study of coding involve?

Answer 2

• 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

Question 3

What were Baddeley’s conclusions about STM?

Answer 3

• coded acoustically
• worse performance with list A than B
• no difference in lists C and D
• STM organises information according to how it sounds

Question 4

What were Baddeley’s conclusions about LTM?

Answer 4

• coded semantically
• no difference in lists A and B
• worse performance with list C than D
• LTM organises information according to its meaning

Question 5

Evaluate Baddeley’s 1966 study.

Answer 5

(+) 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

Question 6

What is the capacity of the Sensory Register?

Answer 6

Unlimited

Question 7

What is the capacity of STM?

Answer 7

7 (+/-) 2 items

Question 8

How did Jacobs (1887) determine the capacity of STM?

Answer 8

• Digit Span Test
• participants given several sequences of digits/letters
• asked to repeat in the correct order
• sequences increased by one item each time

Question 9

What were the results from Jacobs’ 1887 study?

Answer 9

• avg items we hold: 9.3 digits and 7.3 letters

Question 10

What did Miller (1956) do/find?

Answer 10

• reviewed psychological studies
• concluded that span of STM is 7 (+/-) 2
• old information gets displaced
• chunking helps us remember more

Question 11

Evaluate Jacobs’ 1887 study.

Answer 11

(+) first to acknowledge that STM capacity gradually improves with age

(-) Lack temporal validity - conducted in 1887

Question 12

What is the capacity of LTM?

Answer 12

Unlimited

Question 13

What is the duration of the SR?

Answer 13

250 milliseconds

Question 14

How did Peterson and Peterson (1959) determine the duration of STM?

Answer 14

• Nonsense Trigram’s (three random consonants)

- participants asked to count back in 3s from 100 to avoid rehearsal maintenance

Question 15

What were the results from Peterson and Peterson’s (1959) study?

Answer 15

- 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

Question 16

Evaluate Peterson and Peterson’s (1959) study.

Answer 16

(+) High level of control of extraneous variables, using standardised procedures

(-) findings could be due to interference - earlier trigrams confused with later ones

Question 17

What is the duration of LTM?

Answer 17

Potentially a lifetime (unknown)

Question 18

How did Bahrick (1979) determine the duration of LTM?

Answer 18

• 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

Question 19

What were the results from Bahrick’s (1979) photo recognition test?

Answer 19

• identification of faces was accurate:
  90% within 15yrs
  70% within 48yrs

Question 20

What were the results from Bahrick’s (1979) free recall test?

Answer 20

• identification of names was accurate:
  60% within 15yrs
  30% within 48yrs

Question 21

What were the conclusions of Bahrick’s (1979) study?

Answer 21

• LTM duration is potentially a lifetime
• we have retrieval failure
• may need retrieval cues to access information

Question 22

Evaluate Bahrick’s (1979) study.

Answer 22

(+) High ecological validity compared to Peterson and Peterson (1959)

(-) low control of extraneous variables - ie people staying in contact after graduating

Question 23

What is the duration of STM?

Answer 23

18 - 30 seconds