Memory Flashcards
Define capacity
How much data can be held in a memory store
Define duration
A measure of how long a memory lasts before it is no longer available
Define coding
The way information is changed so that it can be stored in memory
State the capacity of the STM and how it was assessed
7 +/- 2
Joseph Jacobs’ digit span task
Describe Miller’s magic number
(1956), wrote an article 7 +/- 2 is the average for the general population, though ‘chunking’ helps even more
Evaluate the capacity of the STM in terms of it being even more limited
Cowan (2001) performed a meta-analysis, said that it is limited to about 4 chunks. Suggests that The STM may not be as extensive as first thought.
Four items may be the limit (Vogel et al. 2001) means that the lower end of Miller’s range is more appropriate.
Evaluate the capacity of the STM in terms of chunking
The size of the chunk affects how many chunks you can remember.
Simon (1974) found that people had a shorter memory span for larger chunks, such as 8-word phrases, than smaller chunks such as 1-syllable words
Evaluate the capacity of the STM in terms of individual differences
STM capacity = not the same for everyone
Jacobs = recall (digit span) increased steadily with age
Could be because of a gradual increase in brain capacity, or people develop strategies e.g. chunking
State the capacity of the LTM
Potentially infinite
State the duration of the STM
0 to 18 seconds
Peterson and Peterson twins study (1959)
24 psychology students recalled trigrams (TGH, CLS)
Intervals = 3, 6, 9, 12, 18
State the procedure of the Peterson and Peterson experiment (1959)
24 psychology students recalled trigrams (TGH, CLS)
Intervals = 3, 6, 9, 12, 18
To prevent rehersal ppts counted backwards in ‘s or 4’s from a specifed number
State the findings of the Peterson and Peterson experiment (1959)
3 seconds = 80% correct recall
6 seconds = fell to 50%
18 seconds = <10% correct recall
State the duration of the LTM
Unlimited
Describe the Harry Bahrick et al. study (1975) for the duration of the LTM
Tested 400 people aged 17-74.
Photo recognition test consisting of 50 photos, some from the ppts high school year-book, who could they remember?
After 48 years = 70% accuracy for photos and 30% accuracy for names.
Evaluate the duration of STM due to artificial testing
Trying to memories consonant syllables does not reflect real life.
Lacks mundane realism and external validity as artificial stimuli used.
Also only considered STM duration, not providing information about other types of stimuli such as pictures and melodies
Evaluate the duration of STM due to ‘STM results may be due to displacement’
Hint = Reitman and Nairne et al
Peterson’s study = counting the numbers in their STM, this may displace or ‘overwrite’ the syllables to be remembered.
Reitman (1974) used auditory tones instead of numbers = no displacement, STM duration was much longer
Nairne et al = items could be recalled as long as 96 seconds
State the type of Coding for STM and LTM
STM = Largely encoded acoustically LTM = Largely encoded semantically
Describe Alan Baddeley’s study into the coding of STM and LTM
Used acoustically similar and semantically similar word lists.
Found that ppts ad difficulty remembering acoustically similar words in STM but not in LTM, and vice-versa.
Shows STM = largely acoustic and LTM = largely semantic
Evaluate Baddeley’s study into memory coding in terms of ‘not testing LTM’
STM was tested by asking ppts to recall a word list immediately after hearing it. LTM was tested by waiting 20 minutes. It is questionable as to whether this is really testing LTM
Evaluate research into memory coding in terms of that the STM may not be exclusively acoustic
Research shows that some visual codes are used in the STM:
Brandimote et al. (1992)
Ppts used visual coding in STM if they were given a visual task, and prevented from doing any verbal rehersal in the retention interval.
What did Wickens et al. do?
Showed that STM sometimes uses a semantic code
Evaluate research into memory coding in terms of that the LTM may not be exclusively semantic
Frost (1972) showed that long-term recall was related to visual as well as semantic categories, and Nelson and Rothbart (1972) found evidence of acoustic coding in LTM.
Therefore it seems that coding in STM or LTM is not simply acoustic or semantic, but can vary according to circumstances.
