Coding, Capacity + Duration of Memory

Question 1

Coding - Definition

Answer 1

The format in which information is stored in the various memory stores

Question 2

Research on coding

Answer 2

Baddeley gave list of words to 4 groups of pps : (1) - acoustically similar , (2) different , (3) semantically similar and (4) different and were shown the original words to recall in order

Found: When recalled from STM, worse results in similar sounding words but from LTM, worse in similar meaning words
SUGGESTS info in STM is coded acoustically + info in LTM is semantic

Question 3

Capacity

Answer 3

The amount of info that can be held in a memory store

Question 4

Research on capacity - Digit Span

Answer 4

Jacobs (1887) - reads out 4 digits + pp recalls these out loud in correct order
If correct research adds another digit until pp cant - indicates digit span

Found mean span for digits = 9.3 and for letters = 7.3

Question 5

Research on capacity - span of memory and chunking

Answer 5

Miller thought span of STM is about 7 items +/-2

Also noted ppl can recall 5 words as well as 5 letters due to chunking - grouping sets of digits or letters into units or chunks

Question 6

Duration

Answer 6

The length of time information can be held in memory

Question 7

Research on duration - STM

Answer 7

Peterson + Peterson (1959) gave 24 students nonsense trigrams and a 3 digit number to count backwards to prevent mental rehearsal

Found: After 3 seconds avg. recall was 80% while after 18 recall was 3%
SUGGESTS that STM duration is about 18 secs w/o verbal rehearsal

Question 8

Research on duration - LTM

Answer 8

Bahrick’s study of 392 US pps aged 17-74 w/ photo recognition test from yearbook + a free recall test of their classmates’ names

Found: 90% accuracy in photo test within 15 years and 70% after 48
Free recall 60% after 15 years 30% after 48

SUGGESTS that LTM lasts up to a lifetime

Question 9

Short term memory - STM

Answer 9

Limited capacity store
Coding - acoustic
Capacity - about 5-9 items
Duration - about 18 seconds

Question 10

Long term memory

Answer 10

Permanent memory store
Coding - semantic
Capacity - unlimited
Duration - up to a lifetime

Question 11

AO3: Research of Coding - Separate memory stores (S)

Answer 11

Later research showed exceptions to Baddeley’s finding but idea of STM is mostly acoustic + LTM is semantic

Important step in understanding of the memory system => led to MSM

Question 12

AO3: Research of Coding - Artifical Stimuli (L)

Answer 12

Baddeley used word lists that had no personal meaning to pps so not conduscive to everyday tasks with more meaningful info - could use semantic coding

SUGGESTS findings have limited application

Question 13

AO3: Research of Capacity - Valid study (S)

Answer 13

Has been replicated as original old study lacked proper controls causing underestimation e.g pps distracted - confounding variable

jacob’s findings have been confirmed, however, by more recent better controlled studies
SUGGESTS Jacobs’ study is a valid test of digit span in STM

Question 14

AO3: Research of Capacity - Overestimated STM capacity (L)

Answer 14

Cowan (2001) reviewed other research + concluded capacityis about 4 +/- 1 chunks

SUGGESTS the lower end of Miller’s estimate (5 items) is more appropriate than 7

Question 15

Limitation of Peterson + Peterson’s Study - Artifical stimulus (Research of Duration)

Answer 15

Not completely irrelevant as we do remember fairly meaningless material like phone numbers
BUT recalling consonant syllables doesn’t reflect everyday use of memory with meaningful info

SUGGESTS study has lack of external validity

Question 16

AO3: Research of Duration - High External validity

Answer 16

Researchers investigated meaningful memories of names + faces unlike other studies of LTM using meaningless pictures => recall rates lowet

SUGGESTS Bahrick et al’s findings reflect a real estimate of LTM