coding capacity and duration Flashcards
What is encoding
The format of the information
stm for encoding?
acoustic encoding (baddeley - acoustic intereference in stm)
ltm for encoding
semantic encoding (baddeley - semantic interference in ltm)
What is the sensory register for encoding?
Multiple stores ; main are echoic (auditory) and iconic (visual)
what is capacity
amount of information that can be held
what is the sensory register for capacity
large capacity
what is the stm for capacity
7 + 2 items of information
jacobs - digit span technique
miller - chunking 7 items
whats the ltm for capacity
potentially unlimited
what is the ltm for duration
up to a lifetime
what is duration
the length of time information is held
what is the sensory registry for duration
milliseconds (1/2 second)
whats the stm for duration
up to 18 seconds without rehearsal (Peterson and Peterson )
what is ltm
- continual storage of information which is largely outside of our awareness, but can be recalled when needed
- info stored semantically, meaning it can hold potentially unlimited amount of information for up to a lifetim
what is a sensory register
- composed of multiple sections,
- capable of holding large amounts of information ,
- only able to retain for a very short time
- for information to pass further into memory system, attention is required
research on capacity - stm
jacobs (1887)
- used serial digit span - ppts are given a string of letters.numbers to learn and repeat back
- found that the capacity of stm is limited
- average recall - digits
9.3 letters = 7.3 - so we can only roughly remember 7 items in stm
miller (1956) chunking may help with this e.g 5932180 = 593/2180
miller found that the average digit span/capacity of items in stm is 7 (plus/minus 2)
what is the stm
- the info we are currently aware of/ thinking about
- info from stm found in from paying attention to sensory information
- info stored acoustically (sounds) for 18 to 20 seconds without rehearsal
- has a limited capacity so can only hold only 7+2 items (miller 1956)
research on during for stm
Peterson and Peterson 1959
P presented with trigrams (string of 3 consonants e.g xqf) and asked to recall the after 3, 6 ,9 12 15 or 18 seconds, counted in 3’s to prevent rehearsal
found that 80% of accuracy rate for trigram recall after 3 seconds, 10% accuracy y after 18 seconds
suggests that stm duration is limited to roughly 18 seconds when rehearsal is prevented
evaluation for capacity - stm
study out of date
lack of control
replicated
evaluation for duration on stm
highly controlled, reliable (can be replicated)
low external validity (not applicable to real life)
research on duration for ltm
barrack et al 1975
- 392 graduates aged 17-74
- recall tested using high school year book by photo recognition and free recall
results. - with photos - 90% accuracy after 15 years, 50-60% accuracy after 48 years , free recall even less (60% and 30%)
supports idea that ltm has a lifetime duration and is semantically encoded
evaluation for duration on ltm
limited duration or affected by other factors e.g age
high external validity (application to real life)
research on coding
baddeley - 1966
-acousticallly similar words e.g cat cab can
-acoustically dissimilar words e.g pit few cow
-sematically similar words e.g great large big
-semantically dissimilar words e.g good huge hot
stm - acoustically similar words were harder to recall than words with dissimilar sounds
ltm - recall was worse for semantically similar words than semantically dismillar words
conclusion - stm codes acoustically, ltm codes semantically
evaluation for research on coding
artificial stimuli, no personal meaning
lack of gerenalisability
high control of extraneous variables - reilability
