Zusammenfassung der Ressource
Nature of Memory
- Short-term
memory
- Memory for immediate events. Has a short
duration (measured in seconds/minutes).
Limited capacity about 4 chunks. Coded
semantically.
- Capacity
- Limited
- Can be assessed
using digit span
- In 1887 Joseph Jacobs used this method to assess STM capacity
- Results: Average span for digits: 9.3 items.
Average span for letters: 7.3
- Jacobs suggested that it's easier to recall
numbers rather than letters because
there are only 9 digits whereas there are
26 letters.
- "The magic number 7±2"
- Article written by George Miller in 1956.
- In the article he reviewed psychological research and concluded that the span of
immediate memory is about 7 items - sometimes more, sometimes less.
- Noted that people can note
7 dots flashed onto a screen
but not many more.
- The same is true for musical notes,
letters and words.
- Also found that people can recall 5 words as well as they can
recall letters - we can chunk things together to remember
more
- Measure of how much can be
held in memory, represented
in bits of info, such as
number of digits
- Duration
- Lloyd and Margret Peterson
1959
- Experiment: 24 students,
each tested over 8 trials.
Each given a consonant
syllable and a 3 digit number
(e.g. THX 512). Asked to
recall the consonant syllable
after retention interval of 3,
6, 9,12, 15 or 18 seconds.
During retention interval
they had to count backwards
from their 3 digit number
- Results (on average): 90% correct over 3 seconds, 20% correct
over 9 seconds and only 2% correct after 18 seconds.
- Suggesting that STM has a very short duration - less
than 18 seconds - as long as rehearsal is prevented
- Measure of how long
a memory lasts before
it is no longer
available.hg
- Coding
- The way information is changed so that
it can be stored in memory. Information
enters the brain via the senses. It is then
stored in various forms such as visual
(like pictures), acoustic (sounds),
semantic (meaning of the experience)
- Alan Baddeley
1966a 1966b
- Used word lists (like the examples above) to
test the effects of acoustic and semantic
similarity on STM and LTM
- Found that participants had difficulty remembering
acoustically similar words in STM but not in LTM
- Whereas acoustically similar
words posed little problem for
STM but led to muddled LTM
- Acoustic and
semantic
coding
- Acoustically similar:
cat,mat, rat, fat ,hat
- Semantically similar:
great, big, large, huge
- Long-term
Memory
- Your memory for events that have happened in
the past. Lasting from 2 minutes to 100 years. LTM
has potentially unlimited duration and capacity
and tends to be coded semantically.
- Capacity