Coding, Capacity And Duration Of Memory

Question 1

What is memory?

Answer 1

Memory is a process in which information is retained about the past

Question 2

What is attention?

Answer 2

The cognitive process of selectively concentrating on one aspect of the environment whilst ignoring surrounding stimuli

Question 3

What is duration?

Answer 3

The length of time that information can be stored in memory

Question 4

What is encoding?

Answer 4

The way information is changed so it can be stored in the memory- the information can be stored in various forms: visually, acoustically or semantically

Question 5

What is capacity?

Answer 5

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

Question 6

What is rehearsal?

Answer 6

Process of repeating information to prevent decay or forgetting (maintenance or elaborative)

Question 7

What are the 3 types of memory?

Answer 7

Sensory register, short-term memory, long-term memory

Question 8

What is the role of the sensory register?

Answer 8

Temporarily stores information from our senses- constantly receives information from around us. Unless we pay attention to it, it disappears through spontaneous decay. Sensory register has a large capacity due to all the senses constantly receiving information from around us e.g. cells on the retina of the eye but with a very limited duration of 1/4-1/2 of a second. Information is coded depending on the sense that has been stimulated

Question 9

What are the sub-categories of the sensory register?

Answer 9

1- haptic store: retains physical senses of touch and internal muscle

2- iconic store: where visual stimuli are kept for a very short time period

3- echoic store: where auditory stimuli are kept briefly

Question 10

Define short-term memory

Answer 10

The limited-capacity memory store. Coding is mainly acoustic; capacity is around 7+/-2 items with duration around 18-30 seconds

Question 11

Define long-term memory

Answer 11

The permanent memory store and coding is semantic. It has unlimited capacity and can store memories for a lifetime

Question 12

What are the 4 key studies we need to know?

Answer 12

1- coding in STM and LTM= Baddeley
2- capacity of STM= Jacobs
3- duration of STM= Peterson and Peterson
4- duration of LTM= Bahrick et al

Question 13

What was the aim of Baddeley’s encoding experiment (1966)?

Answer 13

To explore the effects of acoustic and semantic coding in STM and LTM procedures

Question 14

What was the procedure of Baddeley’s encoding experiment (1966)?

Answer 14

• independent groups
• laboratory experiment

Alan Baddeley gave participants various lists to be recalled later. There were 4 groups of participants, each with a different set of words to be learned:

• group A: acoustically similar words e.g. cat, cab, can
• group B: acoustically dissimilar words e.g. pit, few, cow
• group C: semantically similar words e.g. huge, large, big
• group D: semantically dissimilar words e.g. hot, safe, thin

-STM and LTM tested: participants were asked to recall the words in the correct order. Some participants were asked to recall the words immediately (STM) whereas other had to wait 20 minutes

Question 15

What were the findings and conclusions made from Baddeley’s encoding experiment (1966)

Answer 15

• acoustically similar words remembered worst for STM and semantic for LTM (If participants were asked to recall their word list immediately after hearing it, they tended to do worse with acoustically similar words. If the participants were asked to recall after 20 minutes, they did worse with semantically dissimilar words)

= suggests coding differs between STM and LTM- information coded acoustically in STM and semantically in LTM

Question 16

What’s an evaluation point for Baddeley’s encoding experiment (1966)?

Answer 16

❌ one limitation of the study was that it used rather artificial stimuli than meaningful material that occurs in everyday life. The words in the study had no personal meaning to the participants, meaning we should be cautious about generalising the findings to different kinds of memory tasks. For example, when processing more meaningful information, people may use semantic encoding, even for STM tasks

Question 17

What was the aim of Jacobs’ (1887) capacity of STM experiment?

Answer 17

To investigate how many items could be stored in the STM

Question 18

What was the procedure of Jacobs’ (1887) capacity of STM experiment?

Answer 18

• laboratory experiment
• developed the digit span technique: refers to digits/letters being recalled one at a time- the researcher gives, for example, 4 digits and the participant is asked to recall these in the correct order. If they get this correct, 5 digits is read out by the researcher and so on until the participant cannot recall the order correctly, determining the individual’s digit span

Question 19

What were the findings and conclusions of of Jacobs’ (1887) capacity of STM experiment?

Answer 19

• mean span for digits was 9.3 (on average,participants could repeat back 9.3 digits immediately after they were presented)
• however, on average, participants could only remember a sequence of 7.3 letters

Question 20

What’s an evaluation point for Jacobs’ (1887) capacity of STM experiment?

Answer 20

❌ conducted a long time ago- early research in psychology often lacked adequate control of extraneous variables e.g. Some Ps may have been distracted while they were being tested so they didn’t perform to their best ability. This means the results may lack validity due to the low internal validity of the experiment due to the uncontrolled confounding variables. Although, subsequent research has supported Jacobs’ findings e.g. Miller’s the magic number, seven plus or minus two

Question 21

What was the aim of Peterson and Peterson’s (1959) STM experiment?

Answer 21

To investigate the duration of short-term memory

Question 22

What was the procedure of Peterson and Peterson’s (1959) STM experiment?

Answer 22

• laboratory study
• 24 undergraduate students were given a consonant syllable (also called trigrams) to remember and a 3 digit number. The student was then asked to count backwards from the 3 digit number until told to stop. The counting backwards was intended to prevent mental rehearsal of the consonant syllable (which would increase the students’ memory for the consonant syllable)
• on each trial they were told to stop after a different amount of time- 3,6,9,12,15 or 18 seconds= retention interval

Question 23

What were the findings and conclusions made from Peterson and Peterson’s (1959) STM experiment?

Answer 23

• after 3 second interval, recall of the complete trigram was on average 80%
• recall after 18 seconds interval was about 3% on average
  = suggests that STM has a duration of less than 18 seconds if maintenance rehearsal is prevented. Possibly meaning that STM has a very short duration indeed if maintenance rehearsal is prevented

Question 24

What’s an evaluation point for Peterson and Peterson’s (1959) STM experiment?

Answer 24

❌ one limitation is that the stimulus material was artificial- trying to remember consonant syllables does not reflect most real-life memory activities where what we are trying to remember is meaningful. So it may be argued that this study lacks ecological validity. Although, we do sometimes try to remember fairly meaningless information such as addresses, so the study is not totally relevant and provides a good foundation of knowledge regarding the duration of STM

Question 25

What was the aim of Bahrick et al’s LTM duration experiment?

Answer 25

To investigate the duration of LTM and in particular, ‘very long-term memory’ (VLTM)

Question 26

What was the procedure of Bahrick et al’s LTM duration experiment?

Answer 26

• Bahrick and colleagues studied just under 400 participants aged 17-74 (from the American state of Ohio
• yearbooks were obtained from the participants or directly from some schools and recall was tested in a number of ways:
• photo-recognition test consisting of 50 photos
• free-recall test where participants were asked to list all the names they could remember of individuals in their graduating class

Question 27

What were the findings and conclusions made from Bahrick et al’s duration of LTM experiment? (1975)

Answer 27

• After 48 years this declined to about 70%.
• free recall was around 60% accurate after 15 years but declined to 30% after 48 years
• LTM can last a very long time although may need cues to help access them (why free recall was not as good within 15 years)

Question 28

What are the evaluation points for Bahrick et al’s duration of LTM experiment? (1975)

Answer 28

❌ one limitation of this study is that rehearsal may explain the results- e.g. some participants might have looked at their yearbooks regularly and that’s why their recognition/ free recall was so good; so in this case rehearsal is acting as an extraneous variable = study lacks internal validity and some of the results may not be due to LTM

✅ one strength of this study is that it has high external validity as real-life, meaningful memories were studied as opposed to less-meaningful, artificial ones. When lab studies were conducted with meaningless photos to be remembered, recall rates were significantly lower (Shepard, 1967). Although, a drawback of such real-life research is that confounding variables cannot be controlled and so again, means the study lacks internal validity