Short Term Memory

Question 1

Who researched the capacity of the STM?

Answer 1

Jacobs (1887)

Question 2

Describe Jacobs’ study

Answer 2

• Jacobs created a simple study where he gave participants a list of numbers.
• He would start by giving the
  participants 4 digits to remember, if they got it right he would then give them 5, then 6 etc. until they could not remember them in the right order.
• He then worked out the mean number his participants could
  remember…

Question 3

What was the capacity for the STM according to Jacobs?

Answer 3

Between 5 and 9 items (or 7+-2)

Question 4

Evaluate Jacobs’ study

Answer 4

Pros:
- Useful to everyday life and future research

Cons:
- Early studies lacked control
- Low internal validity
- Lacks mundane realism
- Low external validity

Question 5

Who found out how could we improve STM?

Answer 5

Miller (1956)

Question 6

How can we improve capacity of the STM?

Answer 6

By ‘chunking’ information together

Question 7

Who investigated the duration of the LTM?

Answer 7

Peterson and Peterson

Question 8

Describe Peterson and Peterson’s study

Answer 8

• 24 students given a consonsant syllable (random trigram such as ZDG) to remember.
• Once the pp’s had heard the number they were asked to count down from a random 3 digit number. This counting backwards prevented rehearsal of the trigram.
• On each trial the time the pp’s spent counting backwards increased from 3 seconds, 6, 9, 12, 15, 18 seconds.
• Participants then asked to recall the original trigram correctly.

Question 9

What were the findings?

Answer 9

• Recall after 3 seconds was 80% accurate
• Recall after 18 seconds was 3% accurate.

Question 10

Who studied how the STM codes?

Answer 10

Badderley (1966)

Question 11

Describe Badderley’s study

Answer 11

Gave different lists of words to four groups of participants to remember.
- A list of words that were either ACOUSTICALLY similar (sound the same, e.g. hat, cat, mat etc. )
- A list of words that were ACOUSTICALLLY dissimilar (dog, tap, try).
- A list of words that were either SEMANTICALLY similar (mean the same thing e.g. tall, high big).
- A list of words that were SEMANTICALLY dissimilar (late safe foul).

Question 12

How does the STM code?

Answer 12

When testing for STM (asking PP’s to recall the lists in order immediately), they struggled with the acoustically similar list. The similarity causes confusion as the words interfere with each other – This is because STM codes ACOUSTICALLY.