Memory - coding, capacity and duration

Question 1

What is short term memory?

Answer 1

The limited-capacity memory store
Coding is mainly acoustic (sounds)
Capacity is between 5 and 9 items
Duration is about 18 seconds

Question 2

What is long term memory?

Answer 2

The permanent memory store
Coding is mainly semantic (meaning)
Capacity is unlimited
Can store memories for up to a lifetime

Question 3

What is coding?

Answer 3

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

Question 4

What is capacity?

Answer 4

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

Question 5

What is duration?

Answer 5

The length of time information can be held in the memory

Question 6

Coding - Baddeley, Acoustic and semantic
What was the procedure?

Answer 6

Acoustically similar words (e.g cat cab can) or dissimilar (e.g pit few cow)

Semantically similar words (e.g great large big) or dissimilar (e.g good huge hot)

Question 7

Coding - Baddeley, Acoustic and semantic
What are the findings?

Answer 7

Immediate recall was worse with acoustically similar words, STM is acoustic

Recall after 20 minutes worse with semantically similiar words, LTM is semantic

Question 8

Capacity - Jacobs, Testing digit span
What was the procedure?

Answer 8

Researcher reads four digits and increases until the participant cannot recall the order correctly

Question 9

Capacity - Jacobs, Testing digit span
What are the findings?

Answer 9

On average participants could repeat back 9.3 numbers and 7.3 letters in the correct order immediately after they were presented

Question 10

Capacity - Miller, Magic number 7+_2
What was the procedure?

Answer 10

Miller observed everyday practice, noted that things come in sevens

Question 11

Capacity - Miller, Magic number 7+_2
What are the findings?

Answer 11

The span of STM is about 7 items (plus or minus 2) but is increased by chunking - grouping sets of digits/letters into meaningful units

Question 12

Duration STM - Peterson and Peterson, Consonant syllables
What was the procedure?

Answer 12

24 students were given a consonant syllable to recall and a 3 digit number to count backwards from

The retention interval was varied: 3, 6, 9, 12, 15 or 18 seconds

Question 13

Duration STM - Peterson and Peterson, Consonant syllables
What are the findings?

Answer 13

After 3 seconds - average recall was about 80%.
After 18 seconds it was about 3%
STM duration without rehearsal is up to 18 seconds

Question 14

Duration LTM - Bahrick et al, Yearbook photos
What was the procedure?

Answer 14

Participants were 392 Americans aged between 17 and 74
1) Recognition test - 50 photos from high school yearbooks
2) Free recall test - Participants listed names of their graduating class

Question 15

Duration LTM, Bahrick et al, Yearbook photos
What are the findings?

Answer 15

Recognition test - 90% accurate after 15 yrs, 70% after 48 yrs
Free recall test - 60% recall after 15yrs, 30% after 48 yrs

Question 16

What is a strength and limitation of Baddeley’s study?

Answer 16

Strength - Identified two memory stores
Limitation - Study used artificial stimuli

Question 17

One strength of Baddely’s study is that it identified two memory stores….

Answer 17

Later research showed that there are expections to Baddeley’s findings

But STM is mostly acoustic and LTM is mostly semantic

Lead to the development of the Multi Store Model

Question 18

What is a strength of Jacob’s study?

Answer 18

It has been replicated

Question 19

One strength of Jacob’s study it that it has been replicated….

Answer 19

This is an old study and may have lacked adequate controls (confounding variables e.g participants being distracted)

Despite this, the findings have been confirmed in later controlled studies

Showing study is valid measure of STM digit span

Question 20

What is a limitation of Miller’s research?

Answer 20

It may overestimate STM capacity

Question 21

One limiaiton of Miller’s research is it may overestimate STM capacity……

Answer 21

For example Cowan reviewed other research

Concluded that the capacity of STM was only about 4 (plus or minus 1) chunks

Lower end of Miller’s estimate (5 items) is more appropiate than 7 items

Question 22

What is a limiation of Peterson and Peterson’s study?

Answer 22

Meaningless stimuli

Question 23

A limitation of Peterson and Peterson’s study is meaningless stimuli…..

Answer 23

Sometimes recall meaninglessthings so the study is not completely irrelevant

Recall of consonant syllables does not reflect meaningful everyday memory tasks

Study lacked external validity

Question 24

What is a strength of Bahrick’s study?

Answer 24

High external validity

Question 25

One strength of Bahrick’s study is it had high external validity…

Answer 25

Everyday meaningful memories e.g peoples faces and names, were studied

When lab studies were done with meaningless pictures to be remembered, recall rates were lower

Bahrick’s findingd reflect a more ‘reak’ estimate of the duration of LTM