Coding, capacity ad duration of memory

Question 1

What is short-term memory (STM)?

Answer 1

The limited-capacity memory store.

Coding is mainly acoustic (sounds), capacity is between 5 and 9 items on average, duration is between 18 and 30 seconds.

Question 2

What is long-term memory (LTM)?

Answer 2

The permanent memory store.

Coding is mainly semantic (meaning), it has unlimited capacity and can store memories for up to a lifetime.

Question 3

What id coding?

Answer 3

The format in which info is stored in the various memory stores.

The process of converting info from 1 store to another.

Question 4

Research on coding - Who conducted the research?

Answer 4

Baddeley 1966

Question 5

Research on coding - What were the 4 different lists of words given to the groups?

Answer 5

Baddeley gave different lists of words to 4 groups of ppts to remember:

Group 1 (acoustically similar) - words sounded similar.
Group 2 (acoustically dissimilar) - words sounded different.
Group 3 (semantically similar) - words with similar meanings.
Group 4 (semantically dissimilar) - words all had different meanings.

Question 6

What were ppts asked to do with lists in Baddeley’s research?
What did Baddeley find?

Answer 6

Ppts were shown the words and asked to recall them in the correct order.

When they had to recall them immediately after hearing it (STM recall), they did worse with acoustically similar words.

If ppts were asked to recall the word list after 20 mins (LTM recall), they did worse with the semantically similar words. This suggests that info is coded semantically in LTM.

Question 7

How is info coded in the LTM?

Answer 7

Semantically

Question 8

How is info coded in the STM?

Answer 8

Acoustically

Question 9

What is capacity?

Answer 9

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

Question 10

Research on capacity - Digit span - What is it?

Answer 10

How much info STM can hold at any 1 time.

Question 11

Research on capacity - Who created a technique to measure digit span?

Answer 11

Jacobs 1887

Question 12

What did Jacobs method to investigate digit span entail?

Answer 12

The researcher gives for example 4 numbers and then the ppt is asked to recall these in the correct order out loud.

If they’re correct, the researcher will read out 5 digits and so on until the ppt cannot recall the order correctly.

This determines the individual’s digit span.

Question 13

What was the mean span for digits found by Jacobs?

What was the mean span for letters found by Jacobs?

Answer 13

9. 3

7. 3

Question 14

George Miller 1956 made observations of everyday practice. What did he notice?

What does this suggest about about STM?

Answer 14

He noticed that things come in 7

This suggests that the capacity of STM is about 7 items plus or minus 2.

Question 15

What did Miller also note? (chunking)

Answer 15

Miller also noted that people can recall 5 words as well as they can recall 5 letters. This is done by chunking.

Question 16

What is chunking?

Answer 16

Grouping sets of digits or letters into units or chunks.

Question 17

What is duration?

Answer 17

The length of time that info can be held in memory.

Question 18

Research on duration of STM - Who investigated the duration of STM?

Answer 18

Margaret and Lloyd Peterson 1959

Question 19

How did Margaret and Lloyd Peterson investigate the duration of STM?

Answer 19

Peterson and Peterson tested 24 undergraduate students.

Each student took part in 8 trials.

On each trial the student was given a consonant syllable (e.g YCG) to remember and a 3-digit number.

Ppts were asked to count backwards from the 3-digit number until told to stop.

On each trial the ppt was was told to stop after a different period of time, renging from 3 secs to 18 secs.

Question 20

In Peterson and Peterson’s investigation, why were ppts asked to count backwards from their 3-digit number?

Answer 20

Ppts were asked to count backwards from their number to prevent mental rehearsal of the consonant syllable.

Question 21

What were the findings of Peterson and Peterson’s investigation?

Answer 21

They found that the longer the interval between being given the consonant syllable and being asked to recall it, the less accurate the recall.

Question 22

What do the findings from Peterson and Peterson’s investigation into the duration of STM suggest?

Answer 22

STM has a very short duration unless we go over something over and over again (verbal rehearsal).

Question 23

Research on duration of LTM - who investigated the duration of LTM?

Answer 23

Bahrick and his colleagues 1975

Question 24

Research on duration of LTM - What were the ppts like?

How were the yearbooks obtained?

Answer 24

Bahrick studied 392 ppts from Ohio who were aged 17-74.

Highschool yearbooks were obtained from all ppts or their schools.

Question 25

In what 2 ways was recall tested?

Answer 25

1. Photo-recognition test - this consisted of 50 photos, some from the ppts high school yearbook.
2. Free recall test - ppts recalled all the names of their graduating class.

Question 26

What were the findings of Bahricks investigation for phtot recognition?

Answer 26

Ppts who were tested within 15 years of graduation were about 90% accurate in photo recognition.

After 48 years, recall dropped to about 70% for photo recognition.

Question 27

Free recall was less good than photo recognition. What were the findings for free recall?

Answer 27

After 15 years this was about 60% accurate dropping to 30% after 48 years.

Question 28

What do Bahrick’s findings suggest about the duration of LTM?

Answer 28

LTM can last a very long time.

Question 29

Evaluation of the research on coding - Artificial stimuli - why is this a limitation?

Answer 29

Artificial stimuli was sued rather than meaningful stimuli therefore the word lists had no personal meanings to ppts.

As a result of this we should be more cautious about generalising the findings to different kinds of memory task.

Therefore, findings from this study have limited application.

Question 30

Evaluation of the research on capacity - Jacob’s experiment lacking validity - why is this a limitation?

Give an example of something that would have reduced validity:

Answer 30

Conducted a long time ago so may have lacked adequate control.

For example, some ppts may have been distracted while they were being tested so they didn’t perform as well as they might - confounding variables not controlled.

Question 31

Evaluation of the research on capacity - Lacking validity - counter argument.

Answer 31

The results of this Jacob’s study have been confirmed in other research, supporting its validity.

Question 32

Evaluation of the research on capacity - Miller’s research - not so many chunks - why is this a limitation?

Contradicting research

Answer 32

He may have overestimated the capacity of STM.

For example, Cowan 2001 reviewed other research and concluded that the capacity of STM was only about 4 chunks.

Question 33

Evaluation of the research on capacity - Miller’s research - what did Cowan’s (2001) research suggest about STM?

Answer 33

Cowan’s research suggested that the lower end of Miller’s estimate (5 items) is more appropriate than 7 items.

Question 34

Evaluation of the research into duration of STM - Meaningless stimuli in STM study - why is this a limitation

Answer 34

Stimulus material was artificial so does not reflect real-life memory activities. CONTINUE THIS