memory
coding, capacity and duration of memory
research on coding - information is stored in different forms, depending on the memory
store. Baddeley gave different lists of words to four groups of pps to remember
● group 1: acoustically similar
● group 2: acoustically dissimilar
● group 3: semantically similar
● group 4: semantically dissimilar
pps were shown the original words and asked to recall them in the correct order. when they
did this task immediately, recalling from the short term memory, they tended to do worse with
acoustically similar words. when they recalled the word list after a time of 20 mins, recalling
from long term memory, they did worse with the semantically similar words. suggest info
coded acoustically in stm and sematically in ltm.
research on capacity - jacobs argued an individuals digit span had a mean span of 9.3
items. the mean for letters was 7.3. miller made observations of everyday practice. e.g he
noted that things come in sevens. miller thought that the span of stm is about 7 items, plus
or minus 2. he also noted that people can recall 5 words as easily as they can recall 5
letters. we do this by chunking - grouping sets of digits or letters into units or chunks.
research on duration - the peterson’s tested 24 students in eight trials. on each trial the
student was given a consonant syllable (such as ylg) to remember. also given 3 digit
number. student counted backwards from this number until told to stop. the backwards
counting prevented any mental rehearsing of the syllables. on each time they were told to
stop after varying periods of time. after 3 seconds average recall was about 80%. after 18
seconds, it was about 3%. bahrick studied 392 american pps aged 17 - 74. high school year
books were obtained from the pps or directly from some schools. recall was tested in various
ways , including
● photo recognition test consisting of 50 photos , some from year book.
● free recall test where pps recalled names from their graduating class.
pps tested within 15 years of graduation were about 90% accurate in photo recognition. after
48 years, recalled declined to about 70% from recognition. free recall was shown as less
accurate than recognition - about 60% after 15 years, dropping to 30% after 48 years.
evaluation - coding
✔️ separate memory stores - baddley’s study is that it identified a clear difference between
two memory stores. later research showed that there are some exceptions to baddleys
, findings. but the idea that stm uses mostly acoustic coding and ltm mostly semantic has
stood the test of time.
❌artificial stimuli - word lists had no personal meaning, unrealistic to everyday life.
evaluation - capacity
✔️ valid study - jacobs study is that it has been replicated. the study is very old and early
psychology research often lacked adequate controls. despite this, jacobs study have been
confirmed by better controlled studies (bopp + verhaegen). means it is valid.
❌ not so many chunks - a limitation of millers research is that he may have overestimated
stm capacity. cowan reviewed other research and concluded that the capacity of stm is only
about 4, plus or minus 1 chunks. suggests lower end of millers guess is more appopriate
than seven.
evaluation - duration
❌high external validity - bahrick investigated meaningful memories.
✔️meaningless stimuli in stm study - peterson + peterson’s study lacked external validity as
the task is not relatable to real life.
multi-store model
atkinson + shiffrin’s multi store model describes how information flows through the memory
system. model suggests memory is made up of 3 stores linked by processing.
sensory register - all stimuli from the enviroment passes into the sensory register. this part of
memory comprises several registers, one for each of our five senses. coding in each store is
modality - specific. for example, the store coding for visual memory is iconic and the store for
sound is echoic. duration of material in the sr is very brief - less than half a second. the sr
has a very high capacity information only passes further if you pay attention to it.
short term memory - information in the STM is coded mainly acoustically and lasts about 18
seconds unless it is rehearsed, so STM is more of a temporary store. stm is a
limited-capacity store because it can only contain a certain number of ‘things’ before
forgetting occurs. maintenance rehearsal occurs when we repeat material to ourselves,
therefore it stays in the STM and can be passed to our ltm.
Long-term memory - potentially permanent memory store for information that has been
rehearsed for a prolonged time. LTM is coded semantically.
evaluation
✔️research support - support showing stm and ltm are different. e.g baddeley’s study.
coding, capacity and duration of memory
research on coding - information is stored in different forms, depending on the memory
store. Baddeley gave different lists of words to four groups of pps to remember
● group 1: acoustically similar
● group 2: acoustically dissimilar
● group 3: semantically similar
● group 4: semantically dissimilar
pps were shown the original words and asked to recall them in the correct order. when they
did this task immediately, recalling from the short term memory, they tended to do worse with
acoustically similar words. when they recalled the word list after a time of 20 mins, recalling
from long term memory, they did worse with the semantically similar words. suggest info
coded acoustically in stm and sematically in ltm.
research on capacity - jacobs argued an individuals digit span had a mean span of 9.3
items. the mean for letters was 7.3. miller made observations of everyday practice. e.g he
noted that things come in sevens. miller thought that the span of stm is about 7 items, plus
or minus 2. he also noted that people can recall 5 words as easily as they can recall 5
letters. we do this by chunking - grouping sets of digits or letters into units or chunks.
research on duration - the peterson’s tested 24 students in eight trials. on each trial the
student was given a consonant syllable (such as ylg) to remember. also given 3 digit
number. student counted backwards from this number until told to stop. the backwards
counting prevented any mental rehearsing of the syllables. on each time they were told to
stop after varying periods of time. after 3 seconds average recall was about 80%. after 18
seconds, it was about 3%. bahrick studied 392 american pps aged 17 - 74. high school year
books were obtained from the pps or directly from some schools. recall was tested in various
ways , including
● photo recognition test consisting of 50 photos , some from year book.
● free recall test where pps recalled names from their graduating class.
pps tested within 15 years of graduation were about 90% accurate in photo recognition. after
48 years, recalled declined to about 70% from recognition. free recall was shown as less
accurate than recognition - about 60% after 15 years, dropping to 30% after 48 years.
evaluation - coding
✔️ separate memory stores - baddley’s study is that it identified a clear difference between
two memory stores. later research showed that there are some exceptions to baddleys
, findings. but the idea that stm uses mostly acoustic coding and ltm mostly semantic has
stood the test of time.
❌artificial stimuli - word lists had no personal meaning, unrealistic to everyday life.
evaluation - capacity
✔️ valid study - jacobs study is that it has been replicated. the study is very old and early
psychology research often lacked adequate controls. despite this, jacobs study have been
confirmed by better controlled studies (bopp + verhaegen). means it is valid.
❌ not so many chunks - a limitation of millers research is that he may have overestimated
stm capacity. cowan reviewed other research and concluded that the capacity of stm is only
about 4, plus or minus 1 chunks. suggests lower end of millers guess is more appopriate
than seven.
evaluation - duration
❌high external validity - bahrick investigated meaningful memories.
✔️meaningless stimuli in stm study - peterson + peterson’s study lacked external validity as
the task is not relatable to real life.
multi-store model
atkinson + shiffrin’s multi store model describes how information flows through the memory
system. model suggests memory is made up of 3 stores linked by processing.
sensory register - all stimuli from the enviroment passes into the sensory register. this part of
memory comprises several registers, one for each of our five senses. coding in each store is
modality - specific. for example, the store coding for visual memory is iconic and the store for
sound is echoic. duration of material in the sr is very brief - less than half a second. the sr
has a very high capacity information only passes further if you pay attention to it.
short term memory - information in the STM is coded mainly acoustically and lasts about 18
seconds unless it is rehearsed, so STM is more of a temporary store. stm is a
limited-capacity store because it can only contain a certain number of ‘things’ before
forgetting occurs. maintenance rehearsal occurs when we repeat material to ourselves,
therefore it stays in the STM and can be passed to our ltm.
Long-term memory - potentially permanent memory store for information that has been
rehearsed for a prolonged time. LTM is coded semantically.
evaluation
✔️research support - support showing stm and ltm are different. e.g baddeley’s study.
