Memory

Question 1

Capacity

Answer 1

How much data can be held in a memory store
- LTM has a potentially unlimited capacity
- STM has a limited capacity

Question 2

STM and LTM

Answer 2

STM: for events in the present or immediate past

LTM: for memory in the distant past

Question 3

The research behind capacity of STM

Answer 3

• Capacity can be asses using a digit span

Joseph Jacob’s (1887)
- he used digit spans
- found the average span for digits were 9.3 items
- and the average span for letters were 7.3

• he proposes that the reason for higher retention rate for numbers were because there are only 9 possible numbers but 26 possible letters

Question 4

George miller (1956)

Answer 4

Article on the “magic number 7”

• span of immediate memory is about 7 items, give or take
  -noted that people can count 7 dots when flashed on the screen but not any more.
• he also found that people can recall 5 words jsut as well as they can remember 5 letters

Question 5

AO3: capacity of STM may be even more limited

Answer 5

Criticism of the research investigating STM is that Miller’s original findings have not been replicated.

Cowan (2001) reviewed a variety of studies on the capacity of the STM and concluded that STM is likely to be limited to about 4 chunks instead.

Research on the capacity of STM for visual information (rather than verbal stimuli) also concluded that 4 items were the limit (Vogue et al 2001)
- meant that the lower end of Millers conclusions was appropriate (7-2)

SUGGESTS THAT STM MAY NOT BE AS EXTENSIVE AS WAS THOUGHT

Question 6

AO3: size of chunk matters ( capacity)

Answer 6

It seems that the size of chunk affect how many chunks you can remember

Simon 1974
Found taht people had a shorter memory span for larger chunks (such as 8 work phrases) in contrast to smaller chunks, such as 1 syllable words

THIS CONTINUES TO SUPPORT THE VIEW THAT STM HAS A LIMITED CAPACITY AND REFINES OUR UNDERSTANDING

Question 7

AO3: individual differences (capacity)

Answer 7

The capacity of STM is not the same fro everyone

Jacob’s found that recall (digit span) increased steadily w age

8yo: could Rmb an average of 6.6 digits
19yo: could remember 8.6 digits

This are increase might be due to changes in the brain capacity or the development of strategies such as chunking

THIS SUGGESTS THAT THE CAPACITY OF STM IS NOT FIXED AND INDIVIDUAL DIFFERENCES MAY PLAY A ROLE

Question 8

Duration

Answer 8

LMT potentially lasts forever
SMT doesn’t last long: short duration, unless there is intensive repetition

Question 9

Research behind duration STM

Answer 9

Lloyd and Margaret Peterson (1959) studied the duration of STM using 24 students
- each participant was tested over 8 trials
- each trial, a participant was given a consonant syllable and a 3 digit number
- they were asked to recall the consonant syllable after retention intervals 3,6,9,12,15,18 seconds
- during the retention interval they had to count backwards form their 3 digit number

Participants on average were
90% correct over 3 secs
20% over 9
Only 2% after 18
As long as verbal rehearsal was prevented