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ALL YOU NEED TO KNOW ABOUT MEMORY
MODELS OF MEMORY
Multi-store model
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A linear model with 3 separate stores: sensory store, short-term and long-term stores.
The sensory store has a store for each of the senses, eg. Hearing, vision, touch etc, but
most of it is lost very quickly. Some of the Information is transferred from sensory store,
by paying attention to it, to the short-term store (STM). If info is rehearsed in STM
(acoustically encoded) by repeating it over and over it can be transferred to the longterm memory (LTM ) where there is unlimited duration and capacity. If information is
not rehearsed enough in the STM it is displaced by other incoming information. In the
STM, capacity is limited to about 7 items in STM and only has a duration of about 30
seconds if it isn’t rehearsed. Encoding is acoustic in STM and semantic (for meaning) in
LTM. Information can be retrieved from the LTM when needed.
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Peterson and Peterson’s study of duration in STM used a laboratory experiment which
required participants to recall trigrams (meaningless consonants in 3s that could not be
sounded out as there were no vowels e.g. XRJ) after intervals of 3.6.9.12.15. and 18
seconds. To prevent acoustic rehearsal, participants were required to count aloud in 3s
or 4s from a 3-digit number. Their recall declined over time until recall was almost nil at
18 seconds showing that information does not last for long in STM without rehearsal.
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Digit span is about capacity. Jacobs presented digit strings to participants which
increased in length each time. Participants could recall about 7 digits give or take 2 on
average. This was supported by Miller (Magic number 7). Capacity can be increased by
chunking information because 7 chunks can be recalled rather than 7 separate digits.
This is generally how we try to remember mobile phone numbers.
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Evaluate the MSM
-A very simplistic linear account of a rather complex process.
-The MSM doesn’t account for why some things can be remembered without rehearsal.
KF could put new information into the LTM even though his STM was not working
properly so there must be some other route into LTM. Memories for shocking events
have been shown to imprint directly into LTM without rehearsal and many techniques
improve memory without depending on acoustic rehearsal. Sometimes, things do not
seem to go into LTM even though they are rehearsed.
-Case studies of brain damaged patients such as HM and Clive Wearing support the idea
that STM and LTM are independently functioning stores (their STM functioned relatively
normally while transfer to and retrieval from LTM was impossible). In another case study,
KF had a functioning LTM but an impaired STM (although these case studies also indicate
that there may be more than one component to short-term memories because some
STM tasks were accomplished while others were not). Note that KF can be used to
support and to go against the multi store model.
Brain scanning techniques have shown different areas of the brain activated in STM and
LTM tasks.
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ALL YOU NEED TO KNOW ABOUT MEMORY
The Working model of memory (Baddeley & Hitch)
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The WMM developed STM into a more complex picture of how it works with different
components (so do not criticise it for not focusing on LTM – it never intended to).
The Central Executive is the key component and functions as a director – allocating tasks
to different parts of the model, switching attention etc. The Central executive can
process information from any modality, but has a very limited capacity. The CE has 2
slave systems: The phonological loop has a phonological store (inner ear) and an
articulatory loop (inner voice). The phonological loop uses a sound based code to store
information. This has to be rehearsed by the articulatory control system (agrees with the
MSM for this that acoustic rehearsal is needed). The PS has a limited capacity.
The Visuo-spatial sketchpad (scratchpad) processes input from the eyes or LTM. It has a
visual cache (inner eye) for storing visual spatial information briefly and an inner scribe
which rehearses visual-spatial information.
The WMM provides a much more active model than the MSMs it focuses on processing
information rather than just storing it.
Supporting evidence – Dual task techniques have been used to show that the STM is
divided into different components which can be used simultaneously. Where tasks use
different components, they can be done at the same time, e.g. driving while holding a
conversation – one task uses the visuo spatial sketchpad while the other uses the
phonological store. Where tasks require the same component they interfere with each
other as they compete for the same processes e.g. reading and talking to someone both
require the phonological loop and can’t be done together.
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Evaluation of the WMM
This is very influential model and most cognitive psychologists now call STM working
memory. It has stimulated research and the model has been modified to account for
new findings.
WMM provides a more satisfactory account of the complexity of STM compared with
MSS as it is not just a passive storage system.
Research provides evidence for different components. It explains research finding better
than the MSM and can explain how we can do more than one task simultaneously in
STM, e.g. reading aloud while visually tracking an object. It also explains how we can
remember things without rote rehearsal.
Brain damaged cases also show that the STM can be sub divided for visual and auditory
tasks. It can account for individual differences in memory ability as research has shown
that people differ in their working memory span and that they can score high on visual
working memory tests but low on verbal working memory tests or vice versa.
The role of the Central Executive is the least understood even though it is the most
important component. It is not fully understood how it supervises and coordinates the
slave systems and it is likely that there is more than one component involved in the CE.
Least research has been carried out on this and Baddeley agrees that it is difficult to
investigate the CE.
The model does not account for musical memory and why listening to music does not
impair other tasks that involve acoustic processing.
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ALL YOU NEED TO KNOW ABOUT MEMORY
Eyewitness testimony
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The effect of misleading information
Recall is influenced by the way questions are worded and by additional information fed to them
after an event.
Loftus and Palmer (1974) showed a film of a car accident and then asked questions about it. A
crucial question was asked about the speed of the car. All groups were asked the same question
but a different verb was used (e.g. hit, smashed, bumped, collided, contacted).
Findings Participants who were asked the ‘smashed’ question produced by far the highest
estimate of speed, while those hearing ‘contacted’ gave the lowest estimate of speed.
A week later, participants in the ‘smashed’ condition were more likely to report seeing broken
glass at the accident even though there was none.
For discussion –the verb used hade significant effect on the speed estimate. It continued to affect
recall after a delay of a week, suggesting that the false memory had become permanently lodged
in the memory. Loftus (1975) Participants were shown a film of events leading up to a car
accident. One group was then asked questions consistent with the film. The second group were
asked the same questions except for one concerning a barn (there had been no barn in the film).
Findings – 17% of the misled group reported a barn compared with only 3% of the others.
Loftus concluded that the misled group had incorporated the false info about the barn into their
original memory. Although the result was significant, it is worth noting that not everyone in the
misled group was affected by the post-event info.
Critics of these studies suggested that participants may have been responding to demand
characteristics. Further criticisms include lack of ecological validity in that watching a video of an
event before being asked to recall is an artificial situation that do not mimic real-life situations.
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The effect of anxiety on EWT
There are mixed findings in research studies. Lab studies generally find greater decline in recall
with anxiety. In real life, anxiety seems to enhance recall. Sympathetic arousal in stressful
situations can enhance recall but only up to a point. There seems to be an optimum level after
which recall declines.
People may respond differently in lab experiments – not take it so seriously etc. Watching videos
is not the same as witnessing real life robberies, crashes etc.
Loftus (1979) asked participants to sit outside a laboratory where they thought they were
listening to a genuine exchange between people inside the lab.
Condition one overheard a friendly discussion and then saw a man come out of the room holding
a pen with greasy hands.
Condition 2 overheard a hostile discussion and furniture being overturned and saw a man come
out of the room holding a bloodstained knife. Both sets of participants were asked to identify the
man from 50 photos.
Findings Participants who had witnessed the more violent scene were less accurate in identifying
the man. Loftus concluded that this was because the heightened anxiety of the witnesses in the
violent scene caused them to focus on the weapon and not take in other details
Evaluation This was a staged experiment, but it was similar to real life in that the participants
thought they were waiting to take part in a completely different experiment so were not
expecting to be called as a witness.
The findings of this study have been supported in other research, e.g. Loftus and Christianson
(2006) found that people who were interviewed six months after seeing a traumatic filmed event
could remember the essence of the event very well but had grossly impaired memory of the
details leading up to it.
However, Christianson and Hubinette (1993) surveyed 110 people who between them had
witnessed 22 different bank robberies either as direct victims or as bystanders. The victims of the
crimes who had been subjected to the greatest levels of anxiety were more detailed and accurate
in their recall than the bystanders.
This suggests that people react to anxiety-inducing events differently when they occur in real life
rather than in the laboratory.
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ALL YOU NEED TO KNOW ABOUT MEMORY
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The effect of age on EWT
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There are conflicting findings. It is NOT true to say that older people can’t recall as well
as younger people or memory declines with age.
Anasti and Rhodes (2006) used participants aged 18 – 78 years and found evidence for
own age bias. Participants of different age groups showed better recall for their own age
group when looking at photos of faces.
Warren et al (2005) found older children were more likely to be influenced by leading
questions than adults.
Gruneberg & Morris (1992) found the accuracy of children’ recall is as good as adults if
the context of the original event is reinstated.
Flin et al (1992) asked children and adults questions about an incident they had
witnessed one day after the event and then five months after it. Recall was similar for
adults and children after one day but significantly worse for children after a five month
delay. This has implications for children giving witness in court as there is often a time
delay between the event and the court case.
Gordon et al (2000) reviewed a number of studies of child witnesses and found that
young children were more susceptible to misleading information and leading questions
even though their recall was good. Davies (1994) has disputed this and says that children
can resist misleading information if they are questioned very sensitively.
Yarmey (1984) showed young and elderly adults a film of a staged event and then asked
questions about what they had seen. 80% of elderly adults (compared with only 20% of
young adults) failed to mention that the attacker had a knife in his hand.
Many of these studies use artificial situations which may not reflect how people react to
a real-life situation.
Although the evidence seems quite strong that elderly adults have poorer recall of events
than younger adults, there are always some who recall accurately and are not susceptible
to misleading information. This suggests that there are individual differences- some
people are just better at recalling accurately than others.
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YOU NEED TO DIFFERENTIATE BETWEEN YOUNG AND ELDERLY ADULTS – BE
SPECIFIC ABOUT AGE GROUPS.
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Methodological issues with studies of EWT
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Lab experiments are often artificial and participants may not behave in the way they
would in everyday life (lack of ecological validity).
Watching videos is very artificial and participants may not take it so seriously. Attention
is narrowly focused which may not be the case in real life where there are lots of things
going on. In real situations people are usually taken by surprise and don’t anticipate
being questioned in the way they do during experiments. Some studies try to deal with
this (e.g. Loftus and the weapons effect experiment) – even so people are looking for
demand characteristics if they know they are about to take part in an experiment.
Looking at photos is also different from identifying people in real life.
When working with children, the recall may be more to do with language and
questioning techniques rather than the child’s actual ability to recall.
There are ethical issues involved in terms of informed consent. Also if elderly people are
labeled as being poor eyewitnesses this may result in a small group of people being
disadvantaged. This is known as ‘socially sensitive’ research.
Individual differences should be acknowledged as people are different in their ability to
recall within age groups as well as between them.
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ALL YOU NEED TO KNOW ABOUT MEMORY
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The Cognitive Interview
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Techniques
Geiselman et al (1985) developed the cognitive interview in response to research
findings that showed that the way witnesses were interviewed sometimes stifled recall.
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Context reinstatement – recall the scene, the weather, emotional and cognitive state
etc.
Report everything – report every detail even if trivial – ‘Tell me what you heard, what
you saw’
Recall from a changed perspective – as it would have been seen from different points of
view.
Recall in reverse order – report the episode in different temporal orders, backwards,
forwards etc
The cognitive interview compares favourably with standard interview technique – elicits
more information. More information overall is recalled including more incorrect
information.
Most effective techniques are the first two. Not very successful when questioning young
children under the age of 8.
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Strategies for improving memory
Be prepared to apply any of the following to a context, or to think of an
example of a situation where they could be applied.
Peg-word system
Mnemonics based on organisation and visual imagery
One is a bun; two is a shoe, etc. Peg words to be remembered on to these. E.g. eggs –
bun, bread – shoes. Etc.
Method of loci
A regular route such as a journey to a workplace – visualise key locations and associate
items that need to be remembered with them.
Keyword technique – useful for learning foreign language vocabulary
From an image of a familiar English word – e.g. German word for hedgehog = igel
pronounced eagle – picture an eagle carrying a hedgehog off.
Face name system for remembering names Think of an image similar to the person’s
name, e.g. green – link it to a prominent feature on the person’s face – Baker – baker’s
hat etc.
Acronym e.g. BRASS to remember how to shoot a rifle: breath, relax, aim, sight, squeeze
– first letter of the items to be remembered and make a new word
Acrostic similar to acronym but rather than making a word out of the first letter, you
make a sentence e.g. Richard of York Gave Battle in Vain for the colours of the rainbow.
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