Memory - Coding, capacity and duration

Question 1

What does duration mean?

Answer 1

The length of time that information can be stored in memory

Question 2

What does capacity mean?

Answer 2

The amount of information that can be stored in memory

Question 3

What does coding mean?

Answer 3

A process by which the sensory information is modified and stored in the brain

Question 4

What are the different types of memory stores?

Answer 4

Sensory register
STM
LTM

Question 5

What is the capacity of sensory store?

Answer 5

Very large

Question 6

What is the capacity of STM?

Answer 6

7 +/- 2 items

Question 7

What is the capacity of LTM?

Answer 7

Potentially unlimited

Question 8

Research into capacity: how is STM often assessed?

Answer 8

Digit span task - numbers spanning 3-8 digits, covering all but the first row and moving on if recalled correctly. Digit span is how many digits are recalled correctly

Question 9

Research into capacity: Jacob’s (1887) research on STM

Answer 9

Ppts. read sequence of letters/numbers and asked to repeat it back immediately. Additional digit added on each subsequent trial to measure STM capacity
Average span for numbers = 9.3
Average span for letters = 7.3

Question 10

Research into capacity: Miller’s (1956) research on STM

Answer 10

Reviewed psychological research to conclude ‘the magic number is 7 +/- 2 items’ regardless of whether they’re letters or numbers

Question 11

Research into capacity: what did Miller suggest about chunking?

Answer 11

Argued capacity for remembering info can be increased if we chunk items together. Linking info and grouping together can increase capacity for STM

Question 12

What is a limitation of the research into capacity? - Miller’s potential overestimation for STM capacity

Answer 12

===> Cowan (2001) reviewed research and concluded STM is closer to 4 chunks of info, which may be amore appropriate ‘magic number’ than 7. Important to consider memory can be influenced by individual differences so challenging to draw universal conclusion. Samples used in populations for respective research could have differed and explained different findings

Question 13

What is a limitation of the research into capacity? - Miller’s absence of specification regarding size of chunk

Answer 13

===> Simon (1974) discovered individuals have a smaller STM capacity when dealing with larger chunk, such as 8-word phrases, compared to single syllable words. Suggests Miller’s explanation alone isn’t sufficient to fully account for STM capacity as it’s too vague. Despite this, research supports perspective that STM does have limited capacity

Question 14

What is a limitation of the research into capacity? - Jacob’s capacity estimate isn’t uniform for everyone

Answer 14

===> Jacob’s (1887) research demonstrated digit span recall consistently increased with age. On average, 8 year olds remembered 6.6 digits whilst 19 year olds remembered 8.6. Suggests STM capacity increases with age or develop better strategies to enhance digit span, not mentioned in their findings. Caution should be taken to generalise findings, individual differences influence the STM capacity

Question 15

What is a limitation of the research into capacity? - Lack of ecological validity

Answer 15

===> Studies by Jacobs (1887) and Miller (1956) conducted in artificial settings and used meaningless words, numbers and objects to test memory. Doesn’t reflect how memory is used in the real world. In everyday life, memory carries more personal significance so lack of mundane realism means results only generalised to real-world scenarios

Question 16

What is the duration of sensory store?

Answer 16

Less than 1 second

Question 17

What is the duration of STM?

Answer 17

18-30 seconds

Question 18

What is the duration of LTM?

Answer 18

Potentially infinite

Question 19

Research into duration: Peterson and Peterson (1959) procedure (STM)

Answer 19

On each of 8 trials, 24 uni student ppts. given a consonant trigram (TRX 512) + 3-digit number, asked to recall consonant syllable after intervals of 3,6,9,12,15 or 18s. To prevent rehearsal ppts. had to count back from 3-digit number

Question 20

Research into duration: findings of Peterson and Peterson (1959) (STM)

Answer 20

After 3 seconds, recall accuracy = 80%
After 9 = 20%
After 18 = less than 10%

Conclusion = duration of STM is less than 18 seconds

Question 21

Research into duration: Bahrick et al (1975) procedure (LTM)

Answer 21

392, 17-74 year olds from USA. Ppts.’ asked to name 50 students from high school yearbook photo. Asked to list names from graduating class to investigate duration of LTM

Question 22

Research into duration: Bahrick et al (1975) findings (LTM)

Answer 22

For photos:
Ppts. tested within 15 years of graduation = 90% accuracy
After 48 years = 70% accuracy

For free-recall:
After 15 = 60%
After 48 = 30%

Conclusion = duration of LTM can last a long time

Question 23

What is a limitation of research into duration? - Methodology of Peterson and Peterson (1959)

Answer 23

===> Might not have been measuring trace decay but instead displacement, lowering construct validity. Ppts. asked to engage in distraction task of counting backwards in 3s and 4s so this complex task could have overridden trigrams and resulted in displacement rather than solely preventing rehearsal. Reitman (1974) conducted study using auditory tones instead of counting back so displacement wouldn’t occur. Findings suggest STM duration is longer

Question 24

What is a limitation of research into duration? Peterson and Peterson (1959) questionable ecological validity

Answer 24

===> Stimulus material of consonant trigram used in task was highly artificial so lacked mundane realism as it didn’t reflect real-life examples of memory. People usually required to remember personal events which have greater personal significance than nonsensical syllables. However, in certain situations, we do remember meaningless information like phone numbers, car regs and postcodes so could be representative

Question 25

What is a strength of research into duration? Bahrick et al (1975) higher ecological validity than P+P

Answer 25

===> As ppts.’ memory was tested on their own high school peers, mundane realism enhances generalisability of results. However, introduces confounding variables as some ppts. may remember their friends or classmates better than those who didn’t see each other often. Argued that Bahrick shows high ecological validity but low internal so should be noted when generalising findings

Question 26

How is information encoded in the sensory store?

Answer 26

Modality specific (encoded in the same way it’s received)

Question 27

How is information encoded in the STM?

Answer 27

Acoustically

Question 28

How is information encoded in the LTM?

Answer 28

Semantically

Question 29

Research into coding: Procedure of Baddeley (1966)

Answer 29

Independent group ppts. shown list of words (acoustically/semantically , similar/dissimilar) and asked to recall in correct order. To test STM, ppts. recalled words immediately after hearing them and to test LTM they recalled words after 20 min interval

Question 30

Research into coding: Findings of Baddeley (1966)

Answer 30

STM = struggled remembering acoustically similar words when tested immediately
LTM = had no difficulty remembering acoustically similar words after 20 mins

STM = had no difficulty remembering semantically similar words immediately
LTM = struggled remembering semantically similar words after 20 mins

Question 31

What’s a strength of research into coding? - Demonstrate existence of separate memory stores

Answer 31

===> Baddeley’s (1966) research is fundamental in evidencing that info is encoded acoustically in the STM and info is encoded semantically in the LTM. This proves they’re separate and distinct memory stores and played a crucial role in the development of the MSM. The finding of separate memory stores has consistently withstood the test of time, making it a reliable find

Question 32

What’s a limitation of research into encoding in the STM? - Presence of contradictory research evidence

Answer 32

===> Brandimonte et al (1992) discovered ppts. used visual coding in the STM when engaged in a visual task and were prevented from verbal rehearsal before having to visually recall info. Nelson and Rothbart (1972) found evidence of acoustic coding in LTM, indicating encoding isn’t solely acoustic in STM or semantic in LTM. Generalisability of Baddeley’s findings to all types of learning isn’t equally applicable

Question 33

What’s a limitation of Baddeley’s research into coding? - Lack of ecological validity

Answer 33

===> Research was conducted in a lab setting so it’s hard to generalise findings to real-world contexts. Baddeley used meaningless words to test ppts. recall which doesn’t reflect how memory is used in real life. It carries more personal meaning in reality. His task lacked mundane realism so mightn’t accurately reflect how memory functions in real life