memory - models of memory Flashcards
define coding
the way information is changed so that it can be stored in the memory
3 main ways that information can be encoded:
1) visual (picture)
2) acoustic (sound)
3) semantic (meaning)
define capacity
how much info can be stored
define duration
the period of time information can last in the memory stores
what is short term memory (STM)?
your memory for events in the present or immediate past
what is long term memory (LTM)?
your memory for events that have happened in the more distant past
why can’t we ask people what codes they are using?
coding happens unconsciously
how does the STM code and how do we know?
acoustically → baddeley’s research
when did baddley’s research occur?
1966
the aim of baddley’s research into STM
to examine whether coding in STM is primarily acoustic or semantic
what procedure did baddley use when investigating STM?
-75 participants were divided into 4 groups
-each group heard a list of five words drawn from one of the following categories
(acoustically similar words, acoustically dissimilar words, semantically similar words, semantically dissimilar words)
-immediately after hearing the 5 words they were asked to recall them in the correct order
-this procedure was repeated 4 times
findings of baddeley’s research into STM
-participants given acoustically similar words performed the worst, with a 55%
accuracy
-they confused similar sounding words,
-semantically similar lists only produced a slight detrimental effect
conclusions from baddeley’s research into STM
since acoustically similar words were recalled the least efficiently, it
seems there is acoustic confusion in STM
-suggesting STM is coded acoustically
how does the LTM code and how do we know?
semantically → baddeley’s research
the aim of baddley’s research into LTM
to examine whether coding in LTM is primarily acoustic or semantic
what procedure did baddley’s use while investigating LTM?
-same procedure as his original study, but instead gave his participants a 20-minute interval before recall (now testing LTM)
-during the interval, they conducted another task
findings of baddeley’s research into LTM
-it was found that participants with semantically similar words performed the worst and had only 55% recall
-recall for other lists was 70-85%
conclusions from baddeley’s research into LTM
-there is semantic confusion in LTM
-suggests that LTM is encoded semantically
evaluations of baddeley’s research:
-good validity
-meaningful material was not used
-baddeley may not have tested LTM
ao3 baddeley’s research: good validity
P - a strength of Baddeley’s research into coding is that it has good validity
E - word length was standardised which eliminated some extraneous variables
↳ this allows us to establish cause and effect as we can be more certain that it is the changes in the types of words affecting recall and no other
factor
L - increases the internal validity of
baddeley’s findings into the coding in
memory
ao3 baddeley’s research: meaningful
material was not used
P - limitation of baddeley’s study is that meaningful material was not used
E - the words used in the study had no
personal meaning to participants
↳ this means that baddeley’s findings might not tell us much about coding in everyday life
↳ for example, people tend to use semantic coding even for STM tasks as they have a reason for trying to remember it (e.g. a shopping list)
ao3 baddeley’s research: baddeley may not have tested LTM
P - baddeley may not have tested LTM
E - in the study, STM was tested by asking participants to recall a word list immediately after hearing it, LTM was tested by waiting 20 mins
↳ it is questionable whether this is really testing LTM
L - this casts doubt on the findings of the research into the coding of short and long term memory
what is the capacity of the STM and how do we know?
limited capacity, we can hold only a small amount of information before it is forgotten → jacobs/miller
when did jacobs carry out his research?
1887
who did jacob’s use in his study?
jacobs used a sample of 443 female students from the north london collegiate school
what procedure did jacob’s use to investigate the capacity of the STM?
-jacobs used a digit span test, to examine the capacity of STM for numbers and letters
-he read a list of either letters or numbers, with one syllable (‘w’ and ‘7’ were excluded)
-participants had to repeat back a string of numbers or letters in the same order and the number of digits/letters was gradually increased, until the participants could no longer recall the sequence
what were the findings of jacob’s research into STM?
-jacobs found that STM capacity for digits was 9 (9.3), whereas letters was 7 (7.3)
conclusion of jacob’s research into STM
-STM has a limited capacity of 5-9 digits and that numbers were easier to recall than letters
what happens when new info comes into the STM?
the STM pushes out the old information (displacement) due to its limited capacity
when did miller carry out his research?
1956
miller’s observations
-miller made observations of everyday practice
-he noted that things come in sevens: seven notes on the musical scale, seven days of the week, seven deadly sins
-miller thought that the capacity of STM is about 7 items, plus or minus 2
miller’s magic number
7 plus or minus 2
how did miller demonstrate his observations?
-he read list of digits to participants who immediately had to repeat back each list
in the right order
-the list increased in length 1 digit at a time – the maximum number of digits that could be recalled in the correct order is your immediate memory span
miller and chunking
-miller also noted that people can recall 5 words as easily as they can recall five letters through chunking (grouping sets of digits or letters into chunks)
-even though we can group individual
letters/number/notes to chunks, Miller argued we can still only hold 7+-2 ‘chunks’ of items
-a chunk of information such as an acronym or a date is equal to 1 piece of information
what is the capacity of the LTM and how do we know?
-unlimited capacity
-we know that our brains are not full of information
strengths & weaknesses of jacob’s research
-it was conducted a long time ago
-lack of meaningful material
-biased sample
-syllables were controlled
ao3 jacob’s study: it was conducted a long time ago
P - limitation is that it was conducted a long time ago
E - early research in psychology often lacked adequate controls of extraneous variables
↳ eg: some participants may have been
distracted while they were being tested so they didn’t perform as well
L - this could mean that the results into the capacity of STM may not be valid because there were confounding variables
C - other research, has been able to
replicate digit span studies in more controlled conditions
↳ this suggests that jacob’s and miller’s
study is a valid test of digit span on STM increasing the internal validity of the findings
evaluation of miller’s research
-miller’s research may have overestimated the capacity of STM
-the capacity of STM is not the same for everyone
ao3 miller’s study: miller’s research may have overestimated the capacity of STM
P - a limitation of miller’s research is it may have overestimated the capacity of STM
E - cowen (2001) reviewed other
research and concluded that the capacity of STM was only about 4 chunks
↳ this suggests that the lower end of miller’s estimate (5 items) is more
appropriate than 7 items
↳ although miller’s (1956) theory is supported by psychological research, he did not specify how large each ‘chunk’ of information could be and therefore we are unable to conclude the exact
capacity of STM
L - consequently, further research is required to determine the size of information ‘chunks’ to understand the exact capacity of STM
ao3 miller’s study: the capacity of STM is not the same for everyone
P - the capacity of STM is not the same for everyone
E - jacobs also found that recall in the digit span test increased steadily with age
↳ 8 year olds could remember on average 6.6 digits whereas the mean for 19 year olds was 8.6
↳ this age increase may be due to an increase in brain capacity or that as you get older you develop strategies to improve digit span such as chunking
what is the duration of STM and how do we know?
limited (about 18 secs) → peterson & peterson
when was peterson and peterson’s study conducted?
1959
the aim of peterson & peterson’s study into STM
to test how long the STM lasts when rehearsal is prevented
who did peterson & peterson use in their study into STM?
they used 24 university students to participate in their study
what procedure did peterson and peterson use to study STM?
-participants were shown a
trigram (consonant syllables) and asked to remember it,
-the trigrams were briefly presented to them
-after each trigram participants heard a number and had to count backwards in 3s to prevent them from rehearsal
-counting stopped after a number of time periods (3,6,9,12,15 or 18 seconds) -then participants had to try and recall
the trigram
-this was repeated a number of times using different trigrams
why were consonants chosen?
the inclusion of vowels might have made the trigrams seem more word like, it is important that they are completely meaningless to the participant so they could not use their LTM (eg: BBC)
findings of the peterson and peterson study into STM
-about 80% of the trigrams were correctly recalled after a 3
second retention interval
-dropping to 30% after 9 seconds
-3% after 18 seconds
conclusion of peterson and peterson’s study into STM
if verbal rehearsal is prevented information, information lasts in STM for 18 seconds
strengths and weaknesses of peterson2 study into STM duration
-it was carried out in a laboratory setting
-lacks external validity
ao3 peterson’s study: it was carried out in a laboratory setting
P - one strength of peterson and peterson’s study is that it was carried out in a laboratory setting
E - laboratory settings allows researchers to isolate the IV (trigram) and DV (recall) to test the duration of STM and remove possible extraneous elements variables (rehearsal) which would have influenced
participant’s recall of the trigram
↳ this tightly controlled procedure enabled researchers to find causal links between variables which can provide general laws of the duration of STM
L - we can replicate the research to check for reliability. this increases the validity of the research into the duration of STM
ao3 peterson’s study: lacks ecoval
P - this method can be criticised for
lacking external validity
E – laboratory settings are very artificial in terms of the setting (controlling the IV and EVs) and the task
↳ if participants were asked to
remember everyday items like a shopping list, the duration of STM may be different
L –this research does not allow us to test
our STM in everyday situations which reduces the overall ecological validity of the study into the duration of STM
what is the duration of the LTM and how dw we know?
unlimited/lasts as long as we live → bahrick at all
what was the aim of bahrick at al’s research into LTM duration?
-establish the existence and duration of the LTM
-to see if there is any difference between recognition and recall
who was used in bahrick at al’s study?
graduates from a high school in america
what procedure was used during bahrick at al’s study into the duration of the LTM
-investigators tracked down graduates from a high school in america over a 50 year period
-392 graduates were shown photos from their school yearbook
-participants were aged between 17 and 74
-the time of graduation varied between 2 weeks to 57 years
they were split into 2 groups:
group 1 (recognition group) they were given a picture and a list of names, they had to select the correct name
group 2 (recall group) Asked to name the participants without the list of names
results of bahrick at al’s study
group 1:
recognition of names and pictures and matching of names and pictures all remained high (90%) dropping to 70% after 48 years
group 2:
free recall was less accurate than recognition – 70% accuracy after 3 months, about 60% after 15 years, dropping to 30% after 48 years
conclusions from bahrick at al’s study
people can remember certain types of information for almost a lifetime
evaluations of bahrick at al’s study
-high external validity
-lacks population validity
-his research is unable to explain whether LTM becomes less accurate over time because of a limited duration, or whether LTM simply gets worse with age
ao3 bahrick’s study: high external validity
P - bahrick’s study had high external validity
E - real life meaningful memories were studied, when lab studies were carried out with meaningless pictures to be remembered, recall rates were lower
L - this increases the validity of findings into duration of LTM
C - downside is that confounding variables are not controlled, bahrick’s participants may have looked at their yearbook photos and rehearsed
their memories over the years. this casts doubt on the accuracy of this research into duration of LTM
ao3 bahrick’s study: lacks population validity
P - bahrick’s research used a sample of 392 american university graduates and therefore lacks population validity
E - psychologists are unable to generalise the results of bahrick’s research to other populations
L - we are unable to conclude whether other populations would demonstrate the same ability to recall names and faces after 47 years
ao3 bahrick’s study: why does LTM get less accurate?
P - his research is unable to explain whether LTM becomes less accurate over time because of a limited duration, or whether LTM simply gets worse with age
E - psychologists are unable to determine whether our LTM has an unlimited duration (like the MSM suggests), which is affected by other factors such as getting old, or whether our LTM has a limited duration
what is the MSM?
a representation of our memory
MSM layout:
sensory store → STM → LTM
how does information go from the sensory store to the STM?
attention
how is information kept in the STM?
rehearsal keeps it in the short erm storage and then be transferred to the LTM for potential indefinite storage
what happens if information in the STM isn’t rehearsed?
it is transferred to the LTM
how is information transferred from the LTM to STM?
retrieval
key assumptions of the MSM:
-sensory register, STM and LTM are separate stores
-sensory register, STM and LTM are unitary stores (can’t be further subdivided)
-information passes from store to store in a linear sequential way (one after the other)
-rehearsal is needed to pass information from STM to LTM
LTM
-each store has its own characteristics in terms of coding, capacity and duration
overview of the sensory register
-the first part of our memory where information is held
-whenever we sense environmental stimuli it goes to our sensory register
does the sensory store only have one register?
-this part of memory comprises of several registers stores
-one for each of the five senses
-coding in each store is modality-specific (it depends on the sense)
what is the store that codes acoustically? (sensory)
echoic memory
what is the store that codes visually? (sensory)
iconic memory
capacity of the sensory register
very high
↳ eg: over 100 million cells in each eye
duration of the sensory store
less than half a second
↳ we only pay attention to a small amount of this information
define maintenance rehearsal
continuously repeating information over and over again to keep it in our STM
elaborative rehearsal
the information to your existing knowledge
if rehearsal is done enough information will…
transfer to our LTM
what is meant by retrieval?
getting information out of the LTM and into the STM so it can be remembered
how are retrieval and rehearsal fluid?
we may draw something out of our LTM to remember it when we need it, but then we can let it go back to our LTM after use
ao3 strengths of the MSM:
-evidence from case studies
-evidence to support separate store assumption
-brain scans show that there is a difference between the STM & LTM
ao3 weaknesses of the MSM:
-lack of evidence for unitary store assumption
-rehearsal isn’t always need to transfer information to the LTM
MSM strength: supporting evidence from patients with amnesia (+ counter about external validity)
S - a strength of MSM is that there is supporting evidence from case studies of patients with amnesia
E - HM and clive wearing both had severe damage and lost the ability to form new long-term memories
↳ both had normally functioning short term memories, but as STM only has a duration of up to 30 seconds anything that happened to them was completely forgotten.
L - this provides strong evidence that STM and LTM are completely separate entities in the human brain, and supports this assumption of the MSM
COUNTER:
↳ the evidence has come from case studies → low population validity
case studies only involve the study of one person (brain damage which is not representative of the general population)
↳ we cannot conclude with certainty whether memory is structured in the same way for everyone and whether other people process information in the same way, which threatens the validity of the MSM
MSM strength: there is evidence to support that there are separate stores
P - there is evidence to support the assumptions of the MSM
E - there are controlled lab studies on coding, capacity and duration
↳ these support the existence of a separate STM and LTM stores, which is a key assumption of the MSM
↳ eg: peterson and peterson found that STM duration is 18-30 seconds and bahrick found that LTM has unlimited duration
L - STM is different to LTM in terms of duration, capacity and coding which supports this assumption of MSM; that the two from one another stores are separate and can function independent
MSM strength: evidence from brain scans
P - evidence from brain scans has shown that there is a difference between STM and LTM
E - beardsley found the pre frontal cortex was active during STM tasks but not LTM, suggesting that these memories are stored and processed in different areas of the brain
L - different brain regions are responsible for the different components of the MSM, supporting the idea that our memory is made up of discrete stores
MSM weakness: there a lack of evidence for the assumption that the LTM can’t be subdivided
P - there a lack of evidence for the assumption that STM & LTM are unitary stores
E - HM and clive searing both provide us with evidence that LTM is more complex than just one store
↳ HM had no episodic LTM but could still learn new procedures (golf) despite not remembering ever having done them, he would improve golf every time it was played
L - LTM seems to comprise of more than one component and therefore is not a unitary store
↳ goes against the assumption of MSM that the LTM can’t be sudivided
MSM weakness: rehearsal is not always needed to transfer information to the LTM
P - rehearsal is not always needed to transfer information to the LTM
E - jenkins found that information which interesting, funny or personally relevant can be automatically’ lodged into our LTM without much effort or rehearsal required (incidental learning)
L - this suggests that not all information has to go through the transfer of maintenance and elaborative rehearsal for it to be stored in the LTM
↳ information does not always pass through each store in a linear way, which refutes this assumption of the MSM
outline and evaluate the Multi-Store model of Memory (16 marks) - AO1
-MSM is a linear model of memory (information moves through each component in order)
-the MSM consists of the sensory register, STM and LTM. these are separate and unitary (can’t be subdivided)
-information from the senses is received by the sensory register which has a large capacity but a very short duration - it is modality free which means that it can code for all sense information
-if attention is paid to the information, the information moves to the STM
-this is a temporary store for information with a capacity of 7+/-2, a duration of 18-30 seconds and codes acoustically
-information will disappear from the STM if new information enters (displacement)
-if information in the STM is rehearsed then it can be retained in the STM and then be transferred to the LTM for potential indefinite storage
-LTM is the potentially permanent memory store for information that has been rehearsed for a prolonged time
-it has unlimited capacity and duration and codes semantically
-information can be retrieved from the LTM (getting information out of the LTM so it can be used by the STM)
what is a major issue with the MSM and long term memory?
its’ description of long-term memory as a single, unitary store
who addressed the issue of LTM and the MSM and what did they say?
-endel tulving realised that the multi-store model’s view of long-term memory was too simplistic and inflexible
-he proposed that there are three LTM stores, containing quite different types of information
what are the three LTM stores?
episodic memory, semantic memory and procedural memory
what is an explicit memory?
knowledge for events and facts
-easy to explain
-knowing ‘that’
what is an implicit memory?
skilled behaviours
-difficult to explain
-become automatic through practice
-knowing ‘how’
what is an episodic memory?
(+ example)
includes memories of personal experiences (episodes)
(eg: first day at school)
is episodic memory implicit or explicit?
explicit
which three elements do episodic memories have?
-details of the event
-the context
-emotions
the strength of episodic memories is determined by…
the strength of the emotions experienced when the memory is coded
what part of the brain are episodic memories associated with?
the hippocampus
episodic memories and time:
they are time-stamped
what do all memories start as?
episodic memories
what are semantic memories?
the store for our knowledge for facts, words, concepts & meaning
are semantic memories explicit or implicit?
explicit
what usually must happen for semantic memories to remain in the LTM?
rehearsal
semantic memories & episodic memories:
-semantic memories often start as episodic memories, as we acquire knowledge based on our personal experiences
-semantic memories aren’t time-stamped & they don’t remain closely associated with a particular event
-semantic memories are generally stronger than episodic memories
which part of the brain are semantic memories associated with?
temporal lobe
what is a procedural memory?
-memory of how to perform certain tasks, actions or skills
-difficult to explain
-automatically rehearsed
are procedural memories explicit or implicit?
implicit
how are procedural memories usually acquired?
through repetition and practice
when are many procedural memories formed?
-early in life
-it’s important that these become like second nature to us so that we can focus our attention onto other everyday tasks we perform at the same time
which part of the brain are procedural memories associated with?
the cerebellum (fine motor skills) and motor cortex
ao3 strengths of LTM:
-brain scans provide support for the different types of LTM
-support for the distinction between implicit (procedural memory) and explicit LTM comes from clive wearing
ao3 /strength - brain scans provide for the different types of LTM
P - brain scans provide support for the different types of LTM
E - research has shown that different parts of the brain are active when accessing episodic, semantic and procedural memory
↳ rpisodic memory has been associated with the hippocampus, semantic memory is also associated with the temporal lobe
L - brain scan research suggests that different brain regions are responsible for the different types of LTM, supporting the idea of sub units
ao3 / strength - support for the distinction between implicit (procedural memory) and explicit LTM comes from clive wearing
P - support for the distinction between implicit (procedural memory) and explicit LTM comes from clive wearing
E - clive wearing knew what a piano was (semantic) and he knew how to play it (procedural) but he couldn’t remember playing the piano (episodic)
L - this shows that there is more than one type of LTM
ao3 weaknesses of LTM:
-there is conflicting evidence for the location of the different types of long-term memory
-an issue with the theory of three types of LTM is that it is argued that there may only be two types instead
ao3 / weakness - there is conflicting evidence for the location of the different types of long-term memory
P - there is conflicting evidence for the location of the different types of long-term memory
E - tulving found that episodic memory and semantic memories were both recalled from the prefrontal cortex
↳ left = semantic memories
↳ episodic memories = right
(This also supports the view that there is a physical reality to the different types of LTM, within the brain.)
ao3 / weakness - it is argued that there may only be two types instead
P - it is argued that there may only be two types of LTM
E - cohen and squire argued that episodic and semantic memories are actually stored together in one LTM store called declarative memory (memories that can be consciously recalled)
↳ they agree that procedural memory is a different kind of memory
L - it is important to get the distinction between episodic and semantic memories as it can influence how memory studies are carried out
who proposed the WMM?
baddeley & hitch
key assumptions of the WMM:
-deals only with the STM and recently activated parts of the LTM
-concentrates on how information is processed in the STM & emphasises the idea of an active processor
-proposes that STM is not a gateway in between sensory memory and LTM, information can go straight into LTM from sensory memory
-STM is not a unitary store
what are the parts of the working memory model?
-central executive
-phonological loop
-visuo-spatial sketchpad
-episodic buffer
what is the central executive?
-directs attention to slave systems
-coordinates the actions of the other components
-most important part of WMM
what are the slave systems?
-phonological loop
-visuospatial sketchpad
capacity of the central executive:
very limited processing capacity
coding of the central executive:
modality free:
can store info/code for any sense modality
what is the phonological loop?
-a temporary store for verbal information
-has two components
which two components comprise the phonological loop?
-articulary control process (inner voice)
-phonological store (inner ear)
what does the inner voice (articulary control process) do?
allows for subvocal repetition of acoustic information
what does the inner ear (phonological store) do?
-a temp storage space for coding
acoustic information
-has a limited capacity
capacity and coding of the phonological loop:
-limited capacity
-acoustic coding
what is the visuospatial sketchpad?
-temporary storage space for visual and spatial information
-has two components
what are the two components of the visuospatial sketchpad?
the inner scribe + visual cache
what does the inner scribe do?
it deals with the manipulation of mental images
what does the visual cache do?
-limited capacity for coding visual + spatial info
-stores visual info (colour + shape)
why was the episodic buffer added to the WMM?
the model needed a more general store
what is the episodic buffer?
an extra storage system with limited capacity
strengths of the MSM:
-dual task performance studies support the VSS
-the case of KF supports the existence of subdivisions within STM
-support of the CE from brain scanning studies
ao3 / strength - dual task performance studies support the VSS
P - dual task performance studies support the VSS
E - baddeley et al found participants had more difficulty doing two visual tasks (tracking a light and describing the letter F) than doing a visual and a verbal task at the same time
↳ both visual tasks compete for the same resources (limited capacity of VSS), when doing a verbal and visual task simultaneously there is no competition (VSS & PL)
L - therefore dual task activity provides evidence of the existence of separate slave systems in the WMM. the MSM can’t explain this.
ao3 / strength - the case of KF supports the existence of subdivisions within STM
P - the case of KF supports the existence of subdivisions within STM
E - for KF STM forgetting of auditory information was much greater than that of visual stimuli, his brain damage seemed to be restricted to the phonological loop
↳ he couldn’t remember lists of digits when read out to him (auditory) but remembered significantly more when he read the digits to himself (visual). this suggests that the VSS remains intact
L - the research into KF supports the idea of two slave systems, therefore providing support to the WMM and the idea of a multi-component STM system
ao3 / strength - support of the CE from brain scanning studies
P - there is support of the CE from brain scanning studies
E - braver et al’s participants did tasks involving the CE while they were having a brain scan
↳ activity was seen in an area called the prefrontal cortex
↳ activity in this area increased as the task became harder, this makes sense in terms of the WMM because as demand increases on the CE it has to work harder to function
L - this study provides evidence that the CE may have a physical reality in the brain
criticisms of the MSM:
-it is unclear whether KF had other cognitive impairments which may have affected his performance
-lack of clarity over the CE
ao3 / strength - it is unclear whether KF had other cognitive impairments which may have affected his performance
(KF counterpoint)
P - it’w unclear whether KF had other cognitive impairments (apart from his damage to his phonological loop) which might have affected his performance on memory tasks
E - his injury was caused by a motorcycle accident, the trauma involved may have affected his cognitive performance
L - this challenges evidence for WMM that comes from clinical studies of people with brain injuries that may have affected many different systems
ao3 / strength - lack of clarity over the CE
P - lack of clarity over the CE
E - cognitive psychologists suggest that the CE is unsatisfactory and doesn’t really explain anything
↳ the CE should be more than just paying attention to something and some psychologists believe that it may consist of separate components
L - this means that the WMM has not yet been fully explained
