Slides in this set
Key terms :
· Capacity a measure of how
much can be held in the
· Duration a measure of how
long a memory lasts before it
is no longer available.
· Encoding the way
information is changed so it
can be stored in memory.…read more
SHORT TERM MEMORY
Duration of the STM is around 18 seconds.
Study : Peterson & Peterson (1959)
· Lab experiment
· 24 participants
· Participants were given a consonant syllable (E.
G WRT) to remember + a 3 digit number.
· They were asked to count backwards from
the number until told to stop
· Then had to recall a nonsense trigram.
· This was repeated at different retention
intervals : 3,6,9,12,15 or 18 seconds.…read more
FINDINGS/WHAT IT SHOWED.
As the delay between hearing the
trigram and reporting it
decreased the ability to recall it
decreased. No participant could
recall the letters after more than
When rehearsal is prevented
items in the short term
memory are lost quickly, lasting
around 8 seconds.…read more
EVALUATION OF PETERSON AND
Lacks ecological validity
because the stimulus material
is artificial ad therefore
findings may not apply to all
aspects of everyday life,
though it does apply to
memorising verbal material.…read more
CAPACITY OF STM
· Miller reviewed previous research and
concluded that the span of STM is 7 +_ 2. E.g.
people can cope reasonably with counting 7
dots flashing onto a screen but not many
more than this.
· Jacobs used the digit span technique to assess
the capacity of STM. He found he average
span for digits was 9.3 items, whereas it was
7.3 for letters. This may be because there are
only 10 possible digits (0-9) whereas there
are 26 letters.
· Chunking Miller also found that people
can recall 5 words as ell as they can recall 5
letters we chunk things together and then
an remember more. Simon conducted a lab
experiments and found the size of the chunk
matters and that people had shorter span for…read more