C2 - Coding, capacity & duration of memory

Question 1

Coding - Baddeley (acoustic & semantic)

Answer 1

Procedure:
- Acoustically similar/dissimilar words
- Semantically similar/dissimilar words

Findings:
- Immediate recall worse with acoustically similar, STM is acoustic
- Recall after 20 mins worse with semantically similar, LTM is semantic

Question 2

Evaluations of Baddeley’s coding study (SL)

Answer 2

S - Identified 2 memory stores
L - Used artificial stimuli

Question 3

Baddeley’s coding study - S - Identified 2 memory stores

Answer 3

• Later research showed exceptions to findings
• But, STM mostly acoustic & LTM mostly semantic
• Led to development of MSM

Question 4

Baddeley’s coding study - L - Used artifical stimuli

Answer 4

• Words had no personal meaning to pts, tell little about coding for everyday memory tasks
• When processing more meaningful info, people use semantic coding for STM
• Findings have limited application

Question 5

Capacity - Jacobs (testing digit span)

Answer 5

Procedure:
- Researcher reads 4 digits & increases until pt can’t correctly recall order
- Final number = digit span

Findings:
- Pts repeated back 9.3 numbers & 7.3 letters

Question 6

Capacity - Miller (magic number 7+-2)

Answer 6

Procedure:
- Observed everyday practice, noted things come in sevens

Findings:
- Span of STM is 7 items (+-2), increased by chunking

Question 7

Evaluations of Jacob & Miller’s capacity study (SL)

Answer 7

S - Jacob’s study has been replicated
L - Millers’ research overestimates STM capacity

Question 8

Jacob’s capacity study - S - Has been replicated

Answer 8

• Old study & lacked controls
• Despite this, findings confirmed in later controlled studies
• Study is a valid measure of STM digit span

Question 9

Miller’s capacity study - L - Overestimates STM capacity

Answer 9

• Cowan (2001) reviewed other research
• Concluded capacity of STM only 4 (+-) 1 chunks
• Suggests lower end of Miller’s estimate more appropiate than 7 items

Question 10

Duration STM - Peterson & Peterson (consonant syllables)

Answer 10

Procedure:
- 24 students given consonant syllable (e.g. YCG) to recall & 3 digit number to count backwards from. Retention interval varied.

Findings:
- After 3 seconds, recall 80%. After 18 seconds, recall 3%. STM duration without rehearsal up to 18 seconds.

Question 11

Duration LTM - Bahrick et al (yearbook photos)

Answer 11

Procedure: 392 Americans aged 17-74
1. Recognition test - 50 photos from high school yearbooks
2. Free recall test - Pts listed names of their graduating class

Findings:
1. Recognition test - 90% accurate after 15 years, 70% after 48 years
2. Free recall - 60% recall after 15 years, 30% after 48 years

Question 12

Evaluations of Peterson & Peterson’s STM duration study & Bahrick’s et al LTM duration study (LS)

Answer 12

L - Peterson & Peterson’s study has meaningless stimuli
S - Bahricks et al study had high external validity

Question 13

Peterson & Peterson’s STM duration study - L - Meaningless stimuli

Answer 13

• We sometimes try to recall meaningless things so study isn’t completely irrelevant
• But, recall of consonant syllables doesn’t reflect meaningful everyday memory tasks
• Study lacked external validity

Question 14

Bahrick’s et al study - S - High external validity

Answer 14

• Everyday meaningful memories studied
• Lab studies with meaningless pictures produced lower recall rates
• Findings reflect more ‘real’ estimate of LTM duration