how long does information in the sensory registers last?
around 250milliseconds
how is information stored in the STM?
acoustically
how long does information in the stm last with rehearsal?
18 - 30 seconds
on average how many pieces of information can the stm hold?
7 ± 2 ( 5 - 9 )
how is information stored in the LTM ?
semantically
how long does information stay in the LTM?
lifetime / years
what is the capacity of the LTM?
unlimited
what was the name of jacobs 1887 study?
capacity of short - term memory
what was the aim of jacobs 1887 study?
to investigate the capacity of the short termmemory
what was the procedure of jacobs 1887 study?
he measured digit span - the researcher reads out 4 digits and the participant recalls these out loud in the correct order. if this is correct , the researcher reads out5 digits and so on until the participant cannot recall the order correctly
what was the results of jacobs 1887 study?
it was found that capacity for numbers was 9 items and for letters7 items
what was the name of peterson and peterson 1959 study?
duration of short term memory
what was the aim of peterson and peterson 1959 study?
to investigate the duration of STM
what was the procedure of peterson and peterson 1959 study?
they read nonsense trigrams (Words of three letter that don’t form recognisable words like ZFB) to participants, and then got them to count backwards in threes from a large three-digit number (to prevent repetition of the letters) for varying periods of time.
what was the results of peterson and peterson 1959 study?
after 3 seconds, average recall was about 80 %
after 18 seconds, it was about 3 %
their findings suggested that STM duration may be about 18 seconds unless we repeat the information over and over again ( verbalrehearsal )
what was the conclusions of peterson and peterson 1959 study?
this illustrates that the duration of STM is 18 seconds without rehearsal
what was the name of Baddeley 1966 study?
coding of short term and long term memory
what was the aim of Baddeley 1966 study?
to assess whether coding in STM and LTM is mainly acoustic or semantic
what was the procedure of Baddeley 1966 study? 1/2
75 pps were presented with 1 of 4 word lists repeated 4 times
LIST A - acoustically similar words ( cat , mat , sat )
LIST B - acoustically dissimilar words ( pit , day , cow )
LIST C - semantically similar words ( big , huge , tall )
LIST D - semantically dissimilar words ( hot , safe , foul )
what was the procedure of Baddeley 1966 study? 2/2
To test coding in STM, participants were given a list containing original words in the wrong order.
Their task was to rearrange the words in the correct order.
The procedure for LTM was the same, but with a 20 minute interval before recall, during which participants performed another task to prevent rehearsal.