memory: coding, capacity and the duration of memory

Question 1

what is memory?

Answer 1

the mental processes involved in registering, storing and retrieving information

Question 2

what is short-term memory?

Answer 2

a memory store that can hold a limited amount of information for short periods

Question 3

what is long-term memory?

Answer 3

a memory store that can hold an unlimited amount of information for long periods of time permanently

Question 4

what is coding?

Answer 4

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

Question 5

what are the different types of coding?

Answer 5

• visual coding
• acoustic coding
• semantic coding

Question 6

who did research into the coding of the brain in 1966?

Answer 6

Alan Baddeley in 1966

Question 7

what was the aim of Alan Baddeley’s study (1966)

Answer 7

• to find out if LTM encodes acoustically or semantically by giving participants word lists that are acoustically and semantically similar or dissimilar
• if the participants struggle to recall the word order, it suggests the LTM is confused by similarity which means this is how the LTM tends to encode

Question 8

what were the operationalised IVs in Baddeley’s experiment?

Answer 8

1. Acoustically similar world list or acoustically dissimilar
2. semantically similar word list or semantically dissimilar
3. performance before 15 minutes ‘forgetting’ delay and performance after (performance of interference)

Question 9

what was the operationalised DV in Baddeley’s experiment?

Answer 9

the score on a recall test of 10 words which must be recalled in the correct order

Question 10

what was the procedure of Baddeley’s experiment?

Answer 10

1. the participants are split into four groups according to IV semantically and acoustically similar or dissimilar word lists
2. in the acoustically similar condition, the participants get a list of words that sound similar but the control group get words that are all simple one syllable words that do not sound the same
3. in the semantically similar condition, the participants get a list of words that share similar meaning but the control group gets words that are unconnected
4. the participants in all four conditions then carry out an ‘interference test’ which involves hearing then writing down 8 numbers three times. Then they recall the words from the slideshow in order
5. there are four trials and the participants improve each time they do it because the words stay the same -> only concentrate on getting the order of the words right not remembering the words themselves
6. after the fourth trial, the participants get a 15 min break and perform an unrelated interference task. Then they are asked to recall the list again. This fifth and final trial is unexpected

Question 11

what is a disadvantage of the sampling method Baddeley used?

Answer 11

• used volunteer samples
• open to demand characteristics and could be biased
• by using mostly students it can be ungeneralisable and therefore lacks ecological validity.
• Use of artificial stimuli - meaningful material not used as the word lists had no personal meaning to pps -> hard to generalise findings to different kinds of memory tasks.

Question 12

what is an advantage of the sampling method Baddeley used?

Answer 12

Baddeley used the independent groups design and he uses repeated measures so there’s no participant variables

Question 13

what is an advantage of the experimental controls that Baddeley used?

Answer 13

• he uses the same words each time so it is standardised and repeatable which increases its validity
• there’s also a control group which minimises bias
• there’s a 15 minute interference test each time

Question 14

what were the results of Baddeley’s research into coding?

Answer 14

• acoustically similar words seem to be confusing at first but soon catch up and overtake the control group
• this means the LTM is not confused by acoustic similarities
• semantically similar words do seem to be confusing and the experimental group never catches up with the control group

Question 15

what were the conclusions of Baddeley’s research into coding?

Answer 15

• LTM encodes semantically (dissimilar)
• His earlier experiments suggest STM econdes acoustically (dissimilar)
• LTM gets confused when it has to retrieve words that are semantically similar

Question 16

what does the capacity of memory mean?

Answer 16

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

Question 17

what is the capacity of the LTM and STM?

Answer 17

• the LTM has an unlimited capacity
• the STM has a limited capacity

Question 18

who researched the capacity of STM and when?

Answer 18

Joseph Jacobs in 1887

Question 19

what technique did Jacobs devise?

Answer 19

• the digit span technique
• a participant has to immediately recall a sequence of letters or numbers which increased by one letter or number with each trial.

Question 20

what was the mean score for digits and letters across all participants in Jacobs experiment?

Answer 20

for digits: 9.3
for letters: 7.3

Question 21

what are the advantages of Jacob’s investigation on STM?

Answer 21

• lab experiment so has high levels of control
• standardised procedures so easy to repeat and has high reliability
• the use of different ages can be used to generalise to all members of society (8-19 years)

Question 22

what are the disadvantages of Jacob’s investigation on STM?

Answer 22

• lacks in mundane and ecological validity
• not generalisable to real life
• gender bias as only females were used (443 female students)

Question 23

what did George Miller find in 1956 about the span of memory?

Answer 23

• in 1956, George Miller put forward the idea that most adults can store between 5 and 9 items in their STM
• the STM only has a certain number of ‘slots’ where items can be stored
• Miller called this magic number 7 plus/minus 2

Question 24

what did George Miller find in 1956 about chunking?

Answer 24

• Miller noted that people can recall 5 words and letters
• they do this by chunking through grouping sets of digits/letters into units or chunks

Question 25

what are two limitation of George Miller's findings about chunking?

Answer 25

- Miller did not specify how large each 'chunk' of information could be so we are unable to conclude the exact capacity of STM - Miller may have overestimated the capacity of the STM

Question 26

what is the duration of memory?

Answer 26

the length of time information can be held in the memory

Question 27

who researched the duration of short term memory and when?

Answer 27

Peterson and Peterson in 1959

Question 28

what was the aim of the investigation of Peterson and Peterson?

Answer 28

to investigate the length of STM

Question 29

what was the procedure of Peterson and Peterson's investigation on the duration of memory?

Answer 29

1. 24 undergraduate students took part in 8 trials 2. each student was given a consonant syllable (trigram) to remember and a three digit number 3. students were asked to count backwards from their number to prevent any mental rehearsal

Question 30

what was the IV of Peterson and Peterson's investigation?

Answer 30

on each trial, the pps were told to stop at a different amount of time (3,6,9,12,18 secs) called the retention interval

Question 31

what were the findings of Peterson and Peterson's investigation?

Answer 31

the STM has a short duration unless verbal rehearsal occurs (limited duration of 18-30 secs)

Question 32

what are the limitations of Peterson and Peterson's investigation?

Answer 32

- using psychology students is unreliable as they may have some knowledge of the experiment - lacks mundane realism due to the artificial stimuli so lacks external validity - Spontaneous decay/displacement of information not accounted for

Question 33

who investigated the duration of the LTM and when?

Answer 33

Harry Bahrick et. al in 1975

Question 34

what was the procedure of Bahrick's investigation?

Answer 34

1. used 392 participants aged 17-74 years 2. High school yearbooks were obtained from the pps 3. Recall was tested in two ways: photo-recognition test of 50 photos and a free recall test of all the names of the graduating class

Question 35

what were the findings of Bahrick's investigation on the duration of LTM?

Answer 35

- after 15 years: 90% recognised the photos, 60% recalled classmates - after 48 years: 70% recognised photos, 30% recalled the classmates

Question 36

what conclusions can be made of Bahrick's investigation on the duration of LTM?

Answer 36

the LTM has a lifetime duration of at least 48 years and is semantically encoded

Question 37

what is an advantage and disadvantage of Bahrick's investigation?

Answer 37

- High external validity: meaningful studies were studied so has more real-world application -> when studies on LTM with meaningless photos were conducted, recall rates were lower - (not controlled) Confounding variables: pps may have looked over their yearbook photos and rehearsed their memory over the years