features of Coding , Capacity and Duration Flashcards
what does coding mean
coding is the the way that information is changed to be stored in the memory
what is capacity
capacity is how much information can a store hold at one time
what is duration
duration is the length of time that information can be held in the memory
what is the capacity , duration and coding of the sensory register
capacity - very large
duration - limited
coding is unprocessed
information on the sensory register
the sensory register is the memory store of your 5 sense ( taste , smell , see , hear and touch )
it only holds information for a few seconds
our senses are engaged when exposed to a stimulus eg strong smell
it is the sensory register that allow us to remember a sensory stimulus once expose has ended
key parts :
iconic store - visual information ( what you see )
echoic store - auditory information ( what you hear )
extra :
haptic - feel
gustatory - taste
olfactory - smell
visual memory holds images we see for less than a second before it fades away . auditory memory holds images sound for a few seconds our
coding in the sensory register
information is stored in an unprocessed form . their are different sensory stores for different sensory outputs. iconic - visual , echoic - hear , haptic - feel , gustatory - taste , olfactory - smell . if you pay attention to information it goes to the STM if you don’t then it fades away this is called trace decay
describe the study for the sensory register on duration and capacity ( Sperling - 1960 )
ppt were shown a 3x4 grid of letter for 50 milliseconds and asked to recall as many letters as the could ppt were then asked to recall single row letters when the heard a particular sound
when asked to recall as many letters as they could ppt recalled approx 4 letters when asked to recall the singles row ppt recalled approx 3 items but the items decayed rapidly
- capacity is limited ( minimum 4 items ) and duration is about 250 - 500 milliseconds - though that the image of each item fade during the 50ms and the time it takes to report back
evaluation :
( + ) high control
( - ) low ecological validity
high control as it was a lab experiment- high control over extraneous variables
for example all ppt had the same experience - they were all should the small letter for the same amount of time and where given the same standardised instructions in a control environment - strength result not affected by confounding variables and high internal validity
therefore we can be confident of the findings that capita is large and duration is limited
( - ) low ecological validity
ppt were shown random words in a laboratory and asked to recall this may not be like how information is presented in real life situations
limitation as you not able to generalise how the sensory memory work in real life - low external validity therefore
what is the capacity , duration and coding in the STM
capacity - 7 + / - 2 items
duration - 18-30 seconds
coding - acoustic ( processed through sound )
study - miller ( Capacity in STM ) ( 1956 )
miller using the digit span technique got ppt to listen to a list of numbers and then immediately recall in the correct order
concluded that the span of STM was 7 + / - 2 items and people could remember more when they chinked thing together
evaluation -
( + ) high control
( - ) doesn’t take into account individual differences - age
( - ) individual differences like age
jacob’s found that digit span increased steadily as age increases as 9 year olds could remember 6.6 digits whilst 19 year old could remover 8.6 digits . he also concluded that people found it easier to recall numbers that letters . average span of letters was 7.3 whilst for numbers it was 9.3
limitation as the assumption that all individuals stm can recall between 5 - 9 pieces in of information is over simplistic and may not generalise to how everybody’s STM works - not a fully valid theory
study - peterson and peterson ( Duration in STM ) ( 1959 )
ppt ( 24 undergraduate students ) were presented with constant trigrams and renee was prevented by asking participants to count backwards in 3s from a specific number . after the 3, 6 , 9 , 18 , 30 interval ppt were asked to stop counting and repeated the trigrams
after 3s 80% recall , 18s 10% , 30s no trigrams were recalled
duration 30s or less in maintenance rehearsal is blocked and information fades from stm due to trace decay
evaluation
( + ) high control
( - ) low ecological validity
high control as it is a lab experiment and therefore establishes cause and affect
as it has high control over extraneous variables as ppt were given the same trigrams and same amount of time to recall trigrams we can be confident that the iv ( the number of seconds preventing ppt from rehearsal ) affected the dv ( if the trigrams were recalled accurately )
strength because we can be sure that the result are unlikely to be affected by confounding variables and the findings of duration being 18 -30s has high internal validity
low ecological validity as ppt were presented trigrams and recalling it is an artificial and simplistic task that does test the true complexity of the memory
limitation as results cannot be generalised to real life situation and therefore may not be a valid support for findings
what is the capacity , duration and coding in the LTM
Capacity - unlimited
duration - lifelong
coding - semantic
what is the study for duration in the LTM ( Bahrick et al - 1975 )
investigators interviewed graduates from a high school in America over a 50 year period . 392 graduates were present pictures from their year book and then split into 2 groups
photo group : were given a list of names and asked to select which names matched the people in the pictures
recall group :
asked to name the people in the photos without a list of names
photo group :
15 years - 90% accurately matched names to the person in the photo
48 years - 70% accurately matched names to the person in the photo
recall group :
15 years - 60% could accurately name people with in the photo
48 years - 30% could accurately name people with in the photo
evaluation :
( + ) high ecological validity
( - ) low control
high ecological validity because unlike many memory experiment this experiment used meaningful stimulus material ( high school year book ) and tested people for memories from their own lives
strength as it proves real life evidence to suggest that the duration of the LTM lifelong - high internal validity
low control over extraneous variables
it is possible that ppt identification of their classmates might have been affected by external factors eg if the had recently meet up after high school or not
limitation as bahricks conclusion may not have high internal validity
capacity of the LTM
capacity of Ltm in unlimited - no memory loss and memories only fade due to interference or decay
limitation as it is not possible to establish the capacity of the ltm as it is unlimited and cannot be quantified
limitation as this claim doesn’t have any empirical evidence to support it
coding in STM & LTM - baddeley ( 1966 )
ppt ( british housewives ) were split into 4 groups and shown 10 words that were either semantically similar or dissimilar or acoustically similar or dissimilar
in the STM study ppt were shown the words and immediately after were asked to recall them
in the LTM study ppt were shown the words and then given an interval of 20 minutes to complete another task and the recall the words
in the Ltm study recall of semantically similar words were worse than dissimilar words
in the Stm study recall of acoustically similar words were worse than dissimilar words
coding in the Ltm is semantic as the ltm would get distracted by semantically similar words and model them up
coding in the Stm is acoustic as the stm would get confused by similar sounds and worse for acoustically similar words
evaluation :
(+ ) high control - lab experiment
(-) low ecological validity
baddelys study is a lab experiment and therefore establishes cause and affect. as it is a lab experiment that mean that their is high control over extraneous variable and the research can be confident that their iv ( whether the words were semantic / acoustically different or similar ) affected the dv ( the amount of words recalled ) . strength because it mean that the results are unlike to be affected by confound variables and has high internal validity . therefore we can be confident that codeing in the stm is mainly acoustic and ltm is mainly semantic
limitation low ecological validity
the task of recalling a list of words is artificial and simple task that doesn’t test the true complexity of the memory . limitation as it means that baddelys results cannot necessarily be generalised to real life - low external validity and therefore might not provide valid support for the claim that codeing in ltm is semantic and stm is acoustic
