Coding, capacity and duration of memory

Question 1

What is coding?

Answer 1

Coding is the process of converting information between different forms;

Question 2

Explain the process of Baddeley’s study

Answer 2

He gave different lists of words to four groups of participants to remember
- Group 1 (acoustically similar) e.g. cat, cab, can
- Group 2 (acoustically dissimilar) e.g. pit, few, cow
- Group 3 (semantically similar) e.g great, big, large
- Group 4 (semantically similar) e.g good, huge, hot

Ps were shown the original words and asked to recall them in correct order;

Question 3

What were the findings of Baddeley’s experiment?

Answer 3

When ps did this task immediately, recalling from STM, they tended to do worse with acoustically similar words
When they recalled the word list after a time interval of 20 mins, recalling from LTM, they did worse with semantically similar words;

Question 4

What do Baddeley’s findings suggest?

Answer 4

Information is coded acoustically in STM and semantically in LTM;

Question 5

What is capacity?

Answer 5

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

Question 6

How did Joseph Jacobs measure capacity of the STM

Answer 6

He measured digit span- he read out four digits and the ps recalled them out loud in the correct order, each time adding on an extra digit to recall, until they could no longer correctly recall the numbers;

Question 7

What was the mean span for digits and letters that were correctly recalled

Answer 7

Digits- 9.3
Letters- 7.3;

Question 8

What did Miller think the span of the STM is

Answer 8

7 ±2
(5-9)
He suggested that we remember letters and digits by chunking;

Question 9

What is Duration?

Answer 9

The length of time information can be held in memory;

Question 10

How did Margaret and Lloyd Peterson measure duration of STM?

Answer 10

• They tested 24 students in 8 trials each
• each trial the student was given a consonant syllable to remember (YCG) and a 3 digit number
• the student counted backwards from this number until told to stop
• on each trial they were told to stop after varying periods of time (3,6,9,12,15, or 18 secs);

Question 11

What were the findings of the Petersons’ study

Answer 11

After 3 secs average recall was about 80%
After 18 secs it was about 3%;

Question 12

What do the Petersons’ findings suggest about the duration of the STM?

Answer 12

STM duration may be about 18 secs unless we repeat the information over and over (verbal rehearsal);

Question 13

How did Henry Bahrick et al research the duration of the LTM?

Answer 13

• they studied 392 American ps aged 17-74
• high school yearbooks we’re obtained from each p
  1. Recall was tested using the photo recognition test consisting of 50 photos
  2. Recall was tested using free recall test- ps recalled all the names of their graduating class;

Question 14

What were the findings of Bahrick et al’s study?

Answer 14

• Ps tested within 15 years of graduation were about 90% accurate in photo recognition
• After 48 years, recall declines to 70% for photo recognition
• free recall was less accurate than recognition: 60% after 15 years and 30% after 48 years
  Therefore LTM may last up to a lifetime for some material;

Question 15

What is the strength of Baddeley’s study

Answer 15

it has identified a clear difference between the STM and LTM;

Question 16

What is a limitation of Baddeley’s study

Answer 16

It used artificial stimuli rather than meaningful material
e.g the word lists had no personal meaning to ps, suggesting that this study has limited application;

Question 17

What is a strength of Jacobs’ study?

Answer 17

It has been replicated (e.g by a Bopp and Verhaeghen) so it has high validity and is a valid test of digit span in the STM;

Question 18

What is a limitation of Miller’s research

Answer 18

He may have overestimated STM capacity- other studies suggest that STM capacity is 4± 1
This suggests that the lower end of his estimate (5) is more accurate;

Question 19

What is a limitation of Peterson and Peterson’s study

Answer 19

The stimulus material was artificial- recalling consonant syllables doesn’t reflect everyday memory
It lacks external validity;

Question 20

What is one strength of Bahrick et al’s study

Answer 20

It has high external validity- the findings reflect a more ‘real’ estimate of the duration of LTM;