Studies Of STM & LTM

Question 1

Capacity in STM

Answer 1

JACOBS
AIM - demonstrate how much info can be stored in stm
PROCEDURE - serial digit span technique - repeat a sequence adding a letter/digit each time
FINDINGS - average span - 9.3 digits and 7.3 letters
CONCLUSION - stm has limited capacity and increases by age or people develop strategies (chunking)

Criticism - individual differences in digit span - some recall 4 or 10
- can be improved if digits spoken louder or in a rhythm

Question 2

Capacity in LTM

Answer 2

Said to be unlimited but can appear limited because we cannot access that money

Question 3

Duration in STM

Answer 3

PETERSON & PETERSON
AIM - how long is it before memory trace disappears if rehearsal is prevented
PROCEDURE - participants told 3 random digits then count backwards in 4s or 8s and then attempt to remember first 3 digits
RESULTS - participants remember more when they had a shorter retention interval (3s = 90% 18s = 2%)
CONCLUSION - STM remains for less than 18s- many info disappears whitin 9seconds (75%)

Criticisms - procedure is unlike real life - relates only one aspect of memory
- students not the same (different age had different memory, some may be above intelligence)

Question 4

Duration in LTM

Answer 4

BAHRICK
AIM - find important memory’s easier to remember, compare visual and verbal LTM
PROCEDURE - 400 participants aged 17-74 , free recall test (name everyone in class), photo recognition, name recognition.
Also a photo matching test and name matching test
RESULTS - 15yrs of graduating remember 90% in faces and names after 48yrs remember 80% for name
CONCLUSION- VLTM up to 57yrs after graduation - loss of memory overtime, recognition better than recall( jogs memory)

Criticisms - not controlled, some may have rehearsed this

Question 5

Encoding STM & LTM

Answer 5

BRADDLEY
AIM - support that STM is encoded acoustically and if LTM is affected by acoustic confusions
PROCEDURE - 2 LISTS: acoustically similar, acoustically dissimilar 2 LISTS: semantically similar, semantically dissimilar
Encoding LTM given 20min interval performing another task
RESULTS - those with list A recall 55% - other lists recall 75% words. Those with list C recall 55% - list D recall 85%
CONCLUSIONS - STM encoded by sound. LTM encoded by meaning

Criticisms - stm may not always use acoustic code and can be visual (pictures)
- more than one type of LTM and this only relates to one