Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Title: Do computerised training programs designed to improve working
memory work?
ABSTRACT: A critical review of working memory training
research during the last 10 years is provided. Particular
attention is given to research that has attempted to investigate
the efficacy of commercially marketed computerised training
programs such as 'Cogmed' and 'Jungle Memory'. Claimed
benefits are doubted on the basis that research methodologies
were flawed. It is also argued that the Working Memory model
in its current stage of development was under-specified and
paradigmatically
unsuited
to
working
memory
training
research. Indications in respect of memory training for applied
psychologists working in schools, and possible areas for future
research are suggested.
Introduction
Memory improvement has been of academic and practical interest since the
time of the poet Simonides (circa 500 B.C.). Techniques were documented in
an anonymous text, the Rhetorica ad Herennium - dated between 86 and 82
B.C. (Foer, 2011). Self-help books designed to improve memory have had an
international market appeal for more than a century (e.g. Pitman, 1889;
Loisette, 1896; Young and Gibson,1970; Lorayne and Lucas, 1974,1986;
Johnson, B., 1976; Stine, 1997; Buzan, 2009). National newspapers in the UK
regularly carry adverts for memory improvement courses. Such materials
commonly require a fee to be paid and the completion of special homework.
There has been a significant quantity of independent research supporting the
claims of generic memory improvement courses. For example, a large US
random controlled trial (RCT) study of 3000 older adults (Ball et al., 2002;
Willis et al., 2006) with results analysed at 2 years after the course and at 5
years after, showed that a proprietary training course appeared to have
measurable benefits that generalised and lasted.
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Foer (2011) provided an account of how memory skills can be improved to the
extent that the author was able to enter and win a national memory contest in
the USA. Foer described techniques to store and recall information efficiently
including the use of visualisation keys - so called 'memory palaces', and
elaborative encoding using mnemonics. Foer proposes that memory
improvement was not about increasing capacity but about using mental
resources more skilfully.
There have also been some critical findings. For example, Sullivan and
Madden (2008) failed to find any benefit in using Memory Power materials
with young adults; and Owen and colleagues (Owen et al., 2010) did not
detect any transfer effects from brain-training computer games used by 11000
subjects. Owen's BBC funded and mediated research was criticised by the
Swedish neuroscientist, Torkel Klingberg. Klingberg alleged that there was a
lack of rigour with Owen's research (Callaway, 2010).
What emerged in reviewing the generic memory training literature was that
with the claim that memory had or had not been improved, the nature of an
improvement was often not specified: for example, new memorisation or recall
strategies, speed of storage, speed of recall, accuracy of storage, accuracy of
recall, a memory capacity increase, or a combination of any or all of these.
Working Memory Training
A subset of generic memory training has been the comparatively recent
innovation of working memory training (Gathercole, 2008). Recently there
appeared to be increasing interest from educationalists in the potential of
working memory training (Bakalar, 2008; Buckley, 2008). The working
memory paradigm (Baddeley and Hitch, 1974; Baddeley, 2000), its limitations,
and whether it can be used to meaningfully scrutinise claimed working
memory training outcomes is discussed later. Despite possible limitations, the
market for 'adaptive' computerised working memory training programs
appears ripe. Neuroscientific researchers have made optimistic claims for the
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efficacy of programs such as Jungle Memory (Alloway, 2010) and the
Cogmed Working Memory Training Program (Klingberg, 2009) in respect of
future educational attainment and the amelioration of special educational
needs. For example, Buckley (2008) claimed particular benefits for children
and young people with Down Syndrome and Klingberg et al. (2005) claimed
benefits for children with Attention Deficit Hyperactive Disorder (ADHD).
The term: 'adaptive', as applied to computerised working memory programs
such as Cogmed and Jungle Memory, describes computer programs that
utilise training tasks that are automatically adjusted in difficulty according to a
continual reassessment of a subject's so-called working memory capacity. It is
claimed that a subject's working memory capacity has thus been optimally
exercised and stretched against successive baselines and that the subject’s
working memory capacity has been increased. These newer programs
contrast with older generic memory training materials that endeavour to
provide students with new memory skills and strategies for storage and recall,
but do not claim to increase working memory capacity.
If Klingberg and Alloway were correct about the utility of their respective
adaptive working memory training computer-programs, the international
educational market for Jungle Memory and for the Cogmed program would be
potentially highly profitable.
Recent research review - working memory training
Gathercole (2008) was compelling in a keynote review of research in
emphasising the importance of working memory functioning to the educational
outcomes of children and young people but did not advocate working memory
training. Gathercole advised that teachers needed to take account of deficits
in pupils' working memory by making adjustments to the classroom
environment and to the way that the curriculum was delivered.
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Gathercole suggested that the training of working memory skills using
computer programs showed promise, but that research had not been
conclusive:
'As yet, the precise source of the improvement in working memory
performance in training is not fully understood, and may arise from
enhancement in basic memory capacity, strategies or both.'
(Gathercole, 2008, p.385).
In a book published in the same year Gathercole and Alloway (2008) wrote:
'We have no direct evidence that general working memory capacity can be
improved by training in low [sic] memory children. Some research has
attempted to enhance working memory by training children in the use of highly
specific strategies, but the gains have been small despite intensive training,
and have not generalised to other memory situations.' (p. 106)
Indeed, a review of the small quantity of available research from 20 years ago
to the present day investigating the efficacy of working memory training using
either random control trials or subtractive experimental designs has been
equivocal about its benefits.
Flynn and Storandt (1990) concluded that there were no significant benefits to
be gained from working memory training with older adults. Olson et al.,(2005)
described research where the functioning (speed and accuracy) but not
capacity of visuo-spatial memory was improved after a repeating visual
memory training task had been completed.
Jaeggi et al. (2008) proposed that fluid intelligence was increased after
working memory training had been completed. The researchers noted that
working memory and fluid intelligence shared a 'common variance' (p.1).
Moody (2009) criticised the methodology of this research noting that the
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training tasks employed were similar to the tasks used by the measurement
tool: the BOMAT (Bochum's Standard Matrices, Hossiep and Hasella, 2010).
There were a number of other problems with the research of Jaeggi et al.
(2008) that exemplified the potential for obscuring experimental effects that
pervades much of the research concerned with working memory training.
Jaeggi et al. elected to use a 'no training' control group model. This invited the
criticism that the experimental group had much more experimenter attention
than the control group, and the possibility that there had been a Hawthorne
effect. It also meant that the confounding effect that Moody (2009) identified,
was more pronounced than if an alternative placebo-type training intervention
had been used as a comparison condition. There were also problems with the
specification of the pre- and post-intervention measures of working memory:
digit span and reading span. Chase and Ericsson (1982); and Pickering and
Gathercole (2001) had previously noted limitations in the specificity of the digit
span task as a measure of working memory, and Shipstead et al. (2010)
noted difficulties with the use of reading span. The latter also noted that the
Jaeggi et al. (2008) effect size over time was small.
In Gathercole’s (2008) key note article Gathercole referred to research by
Klingberg et al. (2002; 2005). Klingberg and colleagues proposed that the
Cogmed computer program had improved the functioning of working memory
of a small sample (n=42) of children with ADHD. The improvement claimed
appeared to be in respect of the functioning of the visuo-spatial component of
the working memory of subjects using a span-board (or Corsi blocks) test.
Klingberg reported that an increase in working memory capacity had been
achieved.
Klingberg conceived and designed the Cogmed program in 1999, (CogMed,
2009). Klingberg was also a founding member of Cogmed Systems, the
international program marketing company, and is an executive member of its
board.
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Klingberg and colleagues at the Karolinska Institute, Stockholm, supported
their claim to have increased the capacity of working memory with a study
(Olesen et al., 2004) employing functional magnetic resonance imaging
(fMRI). In two small scale experiments (n=3 male adults; and n=8: 2 male and
6 female adults), researchers scanned subjects whilst performing cognitive
tasks, before, during and after 5 weeks of working memory training. Resultant
scans were used to support the researchers' claim that the Cogmed program
had induced a 'cortical plasticity' (p. 78) that underlay increased task-related
pre-frontal and parietal activity. Jonides (2004), in the same issue of the
journal, suggested caution noting that the quantity of data might be insufficient
to adequately support Klingberg's claims.
A book by Klingberg, 'The Overflowing Brain' (Klingberg, 2009) and a
discursive paper (Klingberg, 2010) attempted to provide theoretical support for
the possibility of working memory capacity increase by suggesting that
working memory tasks recruited neurons in the frontal lobe that then became
specialised for working memory tasks:
'As regards working memory, one theory posits that the sensory information
from the rear parts of the brain is conveyed to the specialised neurons of the
frontal lobe in a way not dissimilar to grandmother cell theory.' (Klingberg,
(2009, p.51)
Grandmother Cell Theory is the theoretical proposition that there are
specialised neurons dedicated exclusively to particular tasks, for example, the
recognition of a person's grandmother (Baddeley et al., 2009) or perhaps
temporary working memory storage. Klingberg continues:
‘There are also studies, however, showing that information cannot always be
gleaned simply from the activity of the nerve cells in the frontal lobes. Certain
cells exhibit working memory activity regardless of the type of stimulus being
memorized.' (p.51)
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Subsequently, Klingberg and colleagues (McNab et al., 2009) proposed a
stronger hypothesis about where in the neuron mechanism the plasticity, and
thus potential for increased working memory capacity was to be found. From
the results of an experiment employing both positron emission tomography
(PET) and fMRI scans of 13 males aged between 20 and 28, the researchers
claimed that:
'We show that the training of working memory [using the Cogmed program]
which improves working memory capacity, is associated with the changes in
the cortical density of cortical dopamine D1 receptors. Fourteen hours of
training over 5 weeks was associated with changes in both prefrontal and
parietal D1 binding potential. This plasticity of the dopamine D1 receptor
system demonstrates a reciprocal interplay between mental activity and brain
biochemistry in vivo.' (p. 800)
This sounds impressive but reading the report indicates:
1. Baseline and post tests used to measure subjects' working memory
capacity were under-specified.
2. Control and experimental conditions in respect of the type of training tasks
that were used were under-specified.
3. It is not clear how similar test tasks and training tasks were.
4. There was no alternative hypothesis; for example, the possibility that it was
the attentional workload that created the effect rather than the plasticity of
working memory.
5. There was no longer term follow-up to ascertain whether the changes in
cortical dopamine D1 receptor binding lasted significantly beyond the period
of training.
6. There might have been a selection effect in respect of such a small
homogeneous group of adult male volunteers.
7. The previous learning and training experiences of subjects did not appear
to have been controlled for.
8. The change in cortical dopamine D1 receptor binding and the claim that this
can be associated with an increase in working memory capacity is
speculative.
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Baddeley (2009) identified general problems with neuro-imaging studies,
citing Duncan and Owen (2000), and noting:
'... a lack of consistency across studies at anything other than the broadest
level.' (p. 66)
Gathercole and colleagues, (Holmes, et al., 2009a; 2009b) also employed the
Cogmed program in research. The authors cited Klingberg's research (2002;
2005) but stopped short of similarly claiming to have achieved an increase in
working memory capacity, attempting instead to demonstrate generalisation
by presenting evidence for gains in subjects’ subsequent educational
outcomes, e.g. improved standardised reading and spelling scores. An
exclusive association where no other variables are playing a part is
improbable however.
Alloway (2010) claimed that training using Jungle Memory (Memosyne, 2007),
an online licensed computer program, marketed by Memosyne Ltd., improved
general learning outcomes, particularly for children with dyslexia, language
impairments, motor dyspraxia, and ADHD. Alloway is listed as the company
secretary for Memosyne Ltd. by Companies House but does not disclose this
in the article. No research findings to support the benefits of Jungle Memory in
respect of any of these conditions were cited. Whilst Klingberg et al.'s
research (2002; 2005) was cited as supporting Alloway’s claims in respect of
using Jungle Memory with children with ADHD, Klingberg (Cogmed, 2009)
has been adamant that only the Cogmed program can achieve the capacity
increasing effect he and colleagues have reported.
Chein and Morrison (2010) conducted a small scale study of 25 female undergraduates. They endeavoured to show the effect of an adaptive working
memory training program on capacity, attentional processes, and reading
comprehension. The outcomes were significantly improved but only re-tested
at the end of the 4 week course and longer term: generalisation could not be
claimed.
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In a subsequent review, Morrison and Chein (2011) reviewed evidence for
positive working memory training outcomes. They concluded that effort and
expectancy effects were generally not accounted for in research - including
their own. Another experimental error they found in much of the research they
reviewed but which their own study was intended to avoid was the use of test
tasks that were similar in both assessment and training phases of
experiments.
Shipstead, Redick and Engle (2010) also compiled a review of research. They
concluded that Chein and Morrison's 2010 study was singularly more
impressive methodologically than most but too small in scale for the results to
be significant. The focus of their review was particularly related to the extent
to which research has demonstrated the generalisation of working memory
training outcomes. With some of the research they review, generalisation was
not an intention, e.g. Klingberg's PET scan research (Oleson et al., 2004).
Nonetheless, summarising their critique, Engle and colleagues report multiple
methodological problems with the research they reviewed including:
1. Inadequate specification of 'near' and 'far' transfer effects, e.g. Klingberg et
al., (2002); Alloway, (2010).
2. Undetectable 'far' transfer effect, e.g. Holmes et al., (2009a; 2009b).
3. Small sample size and / or inadequately specified control group, e.g.
Alloway and Alloway, (2009); Holmes et al., (2009b); Klingberg et al., (2002).
4. Normal maturation and learning not accounted for in post-training
measures, e.g. Klingberg et al., (2005); Holmes et al., (2009a).
5. Previous experience of the subjects of the type of assessment materials
used in research inadequately controlled for, e.g. Holmes et al., (2009a;
2009b).
6. Inadequate control of other cognitive processes affected by test conditions
particularly the way in which fatigue and stress during test procedures affect
attentional processes, e.g. Klingberg et al., (2002; 2005); Oleson et al., (2004)
7. Selection effects, e.g. in respect of the method of ADHD diagnosis being
unspecified e.g. Klingberg et al., (2002; 2005); Holmes et al., (2009b).
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8. Expectancy effect by virtue of subjects association with researchers,
possibly incorporating a Hawthorne effect, e.g. Klingberg, et al., (2002; 2005);
(Oleson et al., 2009).
Shipstead, et al. (2010) concluded that the case for adaptive working memory
training successfully generalising had not been proven.
Adopting a wider view of the working memory training research but
incorporating Shipstead et al.'s (2010) review, it appears that in order to
establish whether working memory training works, researchers have occupied
themselves with proving one of the following:
1. Outcomes have been positive over a long term as proven by test and retest using a working memory test battery.
2. Outcomes have generalised to long-term increases in proprietary measures
of intelligence.
3. Outcomes have been associated with positive long-term changes in the
physiology of the brain.
4. Outcomes have been positively associated with improved educational
learning outcomes over an extended period.
5. A combination of any or all of the above.
Any of these outcomes – had they been plausibly demonstrated, could have
been construed as being indicative of a permanent increase in working
memory capacity. The research evidence remains equivocal however and on
balance it appears that any claim of having achieved working memory
capacity increase has been unfounded.
Discussion
The discussion that follows firstly examines the Baddeley and Hitch (1974)
working memory model and the augmented model that includes an episodic
buffer (Baddeley, 2000) and considers whether there might be inherent
limitations with the model that preclude certainty in respect of working
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memory training research findings; and whether there are competing models
that might offer further illumination on the issue of training efficacy.
The second part of the discussion considers the attribute of capacity as it was
used in the original conceptualisation of the working memory model (Baddeley
and Hitch, 1974) and how it has been subsequently understood by
researchers investigating working memory training.
The third part of the discussion concerns the limitations that might apply to
research methods as they have been employed in investigating working
memory training research.
The term 'working memory' was first employed in 1960 by Miller, Gallanter
and Pribam as a theoretical conjecture. Working memory was refined as a
concept by Atkinson and Shiffrin (1968) but as a subsidiary function of shortterm memory.
The subsequent three component working memory model was a theoretical
device intended to steer experimental memory research (Baddeley, 2001).
Baddeley and Hitch (1974) conceived of working memory as comprising a
visuo-spatial scratchpad, a phonological loop and an attentional controller the central executive. Baddeley described the utility of the working memory
model thus:
'... a theoretical framework whose function was to give an economical and
coherent account of a relatively wide range of data...
... with a capacity to stimulate further research and to incorporate more
precise quantitative and or computational models. '
(Baddeley, 2001, p.85)
Baddeley (2009) summarised that the function of working memory as
originally envisaged in the model was to briefly hold and manipulate limited
amounts of information. Results of working memory processes might be
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subsequently stored in longer-term memory. Baddeley and Hitch (1974) did
not originally propose that there was an analogous neurological / physiological
working memory device singularly localised within the brain.
Demonstrating the theoretical mutability of the model, Baddeley added a new
fourth component - the episodic buffer (Baddeley, 2000), whose function was
to assimilate different types of information, e.g. visual and phonological and
cross-reference it with information held in the short-term memory store.
The role of the episodic buffer was not considered in Klingberg's research
(2002; 2004, 2005); nor by any of the other researchers reviewed here.
Representatively, Klingberg appeared to view the working memory model as a
fixed, three component entity, each component unfractionalised - much as
they were conceived of in 1974. This does not seem to be in keeping with the
flexible evolving paradigm that Baddeley originally envisaged.
It is conceivable that in time other subsystems could be incorporated into the
model; for example, other sensory buffers (Smith and Jondes, 1997) such as:
touch / movement (Smyth, et al., 1988) smell (White, 1998) and taste
(Bermudez-Rattoni et al., 2005). It is also conceivable that apparently
established
components
of
working
memory
might
require
further
fractionalisation (Smith and Jonides 1997). For example; both they and
Henson (2001) make a strong case for distinguishing between visual object
and visuo-spatial material, both by neural mapping and by experimental data.
Pearson (2001) noted the relative difficulty of researching the visuo-spatial
scratchpad without fractionalising the component further. Page and Henson
(2001) challenged the standard conceptualisation of the phonological loop,
suggesting that it is a specialised dedicated system for immediate verbal
recall and implying that another computational sub-system might exist to
manage phonological tasks such as the ordering of data.
In agreement with May (2001), Baddeley (2009) noted the under-specification
of the central executive and highlighted the difficulty of specifying the central
executive without further fractionalisation. Baddeley (2009) also noted the
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relative preponderance of research pertaining to the specification of the
phonological loop, and the potential for the future fractionalisation of all four of
the working memory components.
Klingberg and colleagues (McNab et al., 2009) claimed that the improvement
in working memory following training with the Cogmed computer program
equated to an increase in working memory capacity but working memory was
originally conceptualised as a limited capacity system and each component
was specified partly by its fixed capacity.
'We would like to suggest that the core of the working memory system
consists of a limited capacity "workspace" which can be divided between
storage and control process demands' (Baddeley and Hitch, 1974, p. 76)
Baddeley (2009) described the 'attentional capacity' (p.54) of the central
executive as being able to attend to a maximum of 2 active tasks at once, and
the capacity of the phonological loop as being typically 4 digits, increased to
Miller's (1956) 7 plus or minus 2 by employment of the additional resources of
the newly contrived episodic buffer (Baddeley, 2009; p.56). Cowan (2001)
argued that the fixed capacity of working memory was 3-5 'chunks' of
information. Cowan proposed that a pointer of indicative information in the
working memory work-area of the short-term memory store pointed to the
chunk, e.g. a word, by coordinated use of other short-duration memory traces
in the short-term memory store - perhaps with reference to knowledge held in
the long-term memory store. Cowan's conceptualisation of working memory
was as a complex dynamic attentional process, rather than the neural workareas in themselves.
Whilst researchers agree that full capacity was not developed until
adolescence or early adulthood is attained (Gathercole et al., 2004; Cowan,
1997), the concept of a fixed, limited-capacity system was an essentially
defining characteristic of Baddeley and Hitch's (1974) working memory model.
The original paradigm was not intended to accommodate a potential increase
in capacity - with training or without. Dispensing with the attribute of fixed13 - 31
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capacity, the working memory model differs much less conceptually from
Atkinson and Shiffrin's (1968) 'short term store' memory (STM).
Whilst limited capacity is only a theoretical attribute, it is interesting to adhere
to the constraint, and then review Klingberg's claim of having increased the
working memory capacity of subjects (McNab, 2009) following the completion
of a Cogmed training course, and consider how the effect they observed
might have been caused. Chase and Ericsson (1982), cited by Shipstead et
al.,(2010) report a participant in an experiment who was able to increase digit
span from 7 digits to 82 after an extensive training course. An interview with
the subject revealed that they had learnt to use the memory technique of
‘elaborative encoding’ (Foer, 2011). This technique involves mapping the
information to be learnt on to an existing knowledge base - perhaps within
short term memory, in order to provide a recall key. Foer (ibid.) reported that
his digit span - identified as being an approxmate indicator of the capacity of
the phonological loop (Pickering and Gathercole, 2001), had significantly
increased after practising for a year using generic memorisation and recall
improvement strategies, from 9 to 18 digits. Foer commented that other
measures of his working memory capacity had not increased at all (Foer,
2011, p.266). Klingberg and colleagues. (McNab et al., 2009) did not examine
this possibility that subjects might be learning and using memory skills of this
sort, perhaps inadvertently or subliminally. The change in cortical dopamine
D1 receptor binding that is reported might be as meaningfully associated with
strategy-learning and confidence as with capacity increase.
Interestingly, the comparatively newly-devised - and thus far, underresearched, episodic buffer (Baddeley, 2000) provides an explanatory device
as to how working memory performance is apparently rapidly improved by
novel, perhaps subliminal, self-taught memory strategies and the employment
of information stored in longer term memory. An explanation of how apparent
improvement might be achieved is elaborated by Ericsson (1985) with the
Theory of Skilled Memory. The theory proposed that strategic memory
processes for storage and recall utilising both short-term memory and longterm memory storage can be significantly accelerated and improved through
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training and practice. Whilst Ericsson appeared to not include the working
memory model in the theory, closer reading revealed that Ericsson's
conception of short term memory, and its function to facilitate storage and
recall from long term memory, was analogous to the function of Baddeley's
augmented model (Baddeley, 2000) - particularly including the functionality of
the episodic buffer.
Whilst Andrade (2001) and Baddeley (2003) reflect that the working memory
model of Baddeley and Hitch (1974), augmented by Baddeley (2000) has had
a robust empirical utility for researchers, Andrade concluded:
'There was also a consensus [among working memory researchers] that the
under-specification of the nature and interrelationships of the sub-components
of working memory made the model hard to use and hard to test.' (p.307)
There are also a number of alternative theories of working memory that
compete with Baddeley and Hitch's (1974) model - particularly in placing
greater emphasis on the attentional process as a mediating device that
utilised different memory stores to synthesise complex multi-modal memories.
Cowan's (1999) model proposed that the attentional process was embedded
in short-term memory and that there was little fundamental difference between
different types of memory. Engle's (1996) theory of inhibitory control
suggested that competing demands from the attentional process delimited the
effectiveness of working memory but did not reduce or increase capacity.
Barrouillet and Camos's resource-sharing hypothesis (Barrouillet et al., 2004)
proposed that complex tasks compelled attentional pauses that facilitated
rehearsal using the short term memory store. Ward's (2001) General Episodic
Memory (GEM) theory developed a model of short-term memory that provided
an explanation of an anomaly that has arisen in phonological loop research recency effects during free recall.
The central executive component of Baddeley and Hitch's (1974) working
memory model and the role of attention in managing working memory
resources, offered a particularly problematical aspect for Andrade (2001).
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Andrade reported that all researchers - including Baddeley, appeared to
experience difficulty in specifying:
'... whether there is a coherent cluster of central executive functions or
whether executive functions are too diverse to be usefully encapsulated by a
modified WM model.' (p.301)
In recognition of Donald Broadbent's work on attention (Baddeley (1993),
Baddeley wrote that he had speculated about changing the name of the
‘Working Memory Model’ to the ‘Working Attention Model’. Baddeley
appeared to take an intriguing step towards Cowan's theory (1999) when he
wrote:
'The working memory system is assumed to be capable of holding a limited
number of chunks, each of which contains a series of 'pointers' to relevant
information in long term memory. Hence, while the number of chunks held by
the system is strictly limited, if more can be packed into a chunk as a result of
prior learning, then the effective capacity of the working memory system can
be expanded.' (p.165)
Prior to the development of brain-imaging technology, working memory has
primarily been a theoretical device that has been topographically visualised
and functionally specified only indirectly by observing a person's behaviour
under particular test conditions.
Baddeley's
primary
method
for
investigating
working
memory
was
experimental but he also used evidence obtained from brain lesion studies in
an attempt to triangulate his experimental findings (Baddeley, 2009).
Baddeley's use of lesion studies was small in scale and not intended to locate
the position of working memory in the brain. As with his experiments,
Baddeley used observations to assist in topographically mapping the
distinctive components of working memory by clustering functions. The
sample-size was small and the measurement of lesions inexact.
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Controlling variables adequately in psychology experiments is notoriously
difficult. Shipstead et al. (2010) list some of the variables that need to be
controlled:
1. Individual learning history of subjects
2. Maturation of subjects
3. Other subject selection criteria, e.g. gender
4. Task pre-sensitisation, task-habituation and task-fatigue
5. Regression to the mean
6. Matching of control condition in terms of fatigue and practice effect
To Shipstead et al.'s (2010) list can be added:
7. Task-specific self-efficacy
8. Mental interference, e.g. negative self-talk
9. Sleep, diet and the use of drugs
There is a reliance placed by many researchers on the specificity of what a
proprietary test claims to be testing. For example, the BOMAT is assumed by
Jaeggi et al. (2008) to reliably measure fluid intelligence (Gf); and the Digit
Span Forward of the WMTB-C is assumed to measure the functioning of the
phonological loop. Gould (1981) discussed the limitations of factor analysis as
it has been employed in the construction of intelligence tests such as the
BOMAT. Pickering and Gathercole (2001) noted that none of the sub-tests
brought together in the WMTB-C - including the Digit Span Forward - were
eclusively specific in their relationship with particular sub-components of
working memory. Oberauer et al. (2000) provided a helpful factor analysis of
how different tests map on to working memory components and functions, but
note:
'... most of the working memory tasks from the literature tap two or three
working memory functions which leads to considerable overlap between the
sets of tasks...' (p.1021)
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With the ADHD studies of Klingberg et al.'s (2002; 2005) and Holmes et al.,
(2009b), the diagnosis of subjects as having ADHD is assumed to be robust
and comparable. Different constellations and degrees of symptoms,
iatrogenicity and widely variable diagnostic practices were not considered.
Given the under-specification of the central executive, and the episodic buffer,
mapping the functionality of other components (the phonological loop and the
visuo-spatial scratchpad) by analysing the behaviour of under-specified
subjects completing non-specific tasks, means that there is significant scope
for false or inaccurate correlation of experimental results with the proposed
topographical architecture of Baddeley and Hitch's (1974) working memory
model.
It cannot be doubted that Baddeley and other researchers, concerned with
specifying working memory using an experimental methodology, have refined
the specification considerably, but it is probable that the precision of the
specification is thus far, insufficient to reliably make an association between
working memory training and working memory capacity. This is perhaps a
reason for some researchers such as Klingberg and colleagues opting to use
brain-imaging methods to validate their experimental findings.
Brain imaging research primarily relies on a subtraction method in the
experimental design (Smith and Jonides, 1997). This means that brain images
are compared when a subject is not performing and then performing a task
that is thought to load on specified functions of the brain. Localisation of
functions are then cross-referenced between the scans corresponding to the
different experimental conditions.
Currently, functional brain imaging using fMRI is noisy, physically restrictive
and expensive. Conducting scans using fMRI therefore that there is significant
cognitive interference when working memory tasks are completed, The
arduousness of fMRI scans places a limit on subject-selection criteria.
Expense means that the number of trials or subjects is usually small.
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PET scans are expensive, physiologically hazardous and temporally
inaccurate with a resolution of 30 seconds and a spatial resolution of 10
millimetres (Smith and Jonides, 1997). fMRI scans are more temporally
accurate with a resolution of 1 to 4 seconds and a spatial resolution of 1
millimetre (Ward, 2010). Nether technology produces sufficient spatial
precision over time to be sure about the association between brief behavioural
events (<3 seconds) and brief brain events (=<2.5 seconds) with a varying
haemodynamic scan delay of approximately 5 seconds (Smith and Jonides
1997]. One fMRI study (Cohen et al., 1997) attempted to map brain events
associated with the use of working memory onto brain areas associated with
particular working memory functions in a more temporally accurate way but
their results appeared speculative:
'A different possibility is that sustained activation within the PFC [pre-frontal
cortex] reflects the operation of more general process associated with task
difficulty and mental effort, rather than a process specific to working memory.'
(p.606)
It might be that future improvements in brain-imaging methods, perhaps
through the development of more sophisticated fMRI and PET scan
technology, will provide additional evidence for the association.
Klingberg and colleagues (Oleson et al., 2004) could be challenged that they
have exaggerated the precision of their claim of having shown the effect of the
Cogmed working memory training course in increasing capacity. Whilst the
changes in cortical dopamine D1 receptor binding can possibly be associated
with the cognitive training as described in the paper, the case for the
essentialness of Cogmed cognitive training is not made. Neither is the case
convincingly made that the changes in the D1 receptor binding equate with an
increase in the capacity of working memory.
Whilst Henson (2000) is confident about being able to approximately locate
the whereabouts of a number of working memory components in the brain,
the working memory training researcher's task in examining brain images to
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show training effects is a more complex task than, for example, identifying a
language or movement centre; or indeed the approximate location of memory
centres. The theoretical construct of working memory is comprised of an
unfixed number of components (4 plus). Being able to record matrices of fast
temporal activity vectors acting between different brain areas, interfered with,
and inhibited by, constant sensory feedback, and interactions with short and
long term memories is critical to brain-imaging research adequately specifying
the working memory model and the effect of any training upon it. We are not
even close.
The role of learnt strategies in the effective employment of this complex matrix
of cognitive activity is not adequately controlled-for in any of the brain-imaging
research discussed here.
Baddeley (2003) previously cautioned:
'The problem of adequately controlling strategy in imaging studies is important
but, I suspect, frequently underestimated. Purely behavioural studies typically
use a series of experiments to rule out the possible strategic interpretations of
the data, an approach that might be seen as impracticably expensive in
neuro-imaging.' (p. 837)
Conclusions: indications for research and recommendations for applied
psychologists
This review of working memory training research has indicated that the
evidence for efficacy is weak. Adaptive computerised training programs such
as Cogmed (2009) and Jungle Memory (Memosyne Ltd., 2007) require
significant amounts of user time, and are costly to buy. Research
methodologies employed to demonstrate efficacy, including brain-imaging
studies, have been found to be flawed. Many of the research difficulties have
arisen because both the Working Memory model (Baddeley and Hitch, 1974)
and the augmented version (Baddeley, 2000) are under-specified for the
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purpose of the research reviewed here and were not intended for use by a
training paradigm.
This review has revealed by implication that there are a number of promising
areas of research and associated indications for applied psychology in the
educational domain:
1. The role of attention
Attention and interference appear to be significant variables in promoting or
inhibiting the use of working memory and short-term memory (Redick, et al.
2011). Consider, for example, a child in school who has intruding thoughts
and anxieties and how this might effect their use of working memory and thus
all of their learning in school. This consideration provides support for
Gathercole's (2008) recommendation that classroom organisation and
learning tasks need to be adapted for children who experience working
memory difficulties.
2. The role of mental effort
The available mental effort for any working memory task affects, and is
affected by, a person's physiological condition, particularly including their
cardiovascular condition and glucose levels (Fairclough, et al. 2004).
Consider, for example, the under-nourished child in the classroom and the
role of diet and meal recency, fatigue, sleep and time of day, prescribed
medication and drug misuse.
3. The role of motivation and memory self-efficacy
It is evident that a person's motivation to use working memory and to learn,
has a complex relationship with memory self-efficacy. There is evidence that a
person's motivation to use working memory affects and is affected by their
confidence that this will be a successful activity (Beaudoin, M., Desrichard, O.
2011; Dougall, 2009). Consider, for example, a child who has under21 - 31
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developed memory self-efficacy and avoids using working memory, short-term
memory, and/or memory strategies/skills as a result of previous learning
failure.
4. The role of memory skills and strategies
There have been a number of indications in this review of the importance of
learnt memorisation and recall strategies and the indirect positive effect they
might apparently have on working memory functioning, even to the extent of
appearing to increase working memory capacity. For example, a study looking
at the acquisition of reading skills (McNamara and Scott, 2001) showed how
learners who had practised memory strategies appeared to use working
memory more effectively when learning to read. The theory of skilled memory
(Ericsson, 1985) provides both theory and suggestions for practice that can
be used to inform interventions in schools. Buzan has provided prolific
guidance on teaching a range of memory skills and strategies (typically,1995,
and 2009), including the use of mind-maps, to children and adults, and
McPherson (2000) provides concise useful guidance with helpful theoretical
underpinnings.
It is probable that teaching children and young people to use memorisation
and recall strategies would parsimoniously provide a curricularly valid and
useful way of promoting improved learning outcomes. Teaching memory skills
(rather than training working memory) might also positively impact upon the
speed, efficiency, accuracy and confidence of using working memory
functions.
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References
Alloway, T.P. (2007) Automated Working Memory Assessment, UK: Pearson
Assessment
Alloway, T.P., (2009) 'Working Memory but Not IQ Predicts Subsequent
Learning in children with Learning Difficulties' European Journal of
Psychological Assessment 25, 2, pp. 92-98
Alloway, T.P., (2010), 'Brain Training' Nasen Special, May, pp.35-37,
www.Nasen.org.uk
Andrade, J., (2001) 'Concensus, controversy and future directions' in J.
Andrade (Ed.) Working Memory in Perspective, UK: Psychology Press
Atkinson, R. C., Shiffrin, R. M., (1968) 'Human Memory: A proposed system
and control processes.' In K.W. Spence & J.D. Spence (Eds.) The Psychology
of Learning and Motivation, Vol.2, (pp. 89-195), N.Y.: Academic Press
Bacon, J.H. Rev. (1889) The Complete Guide To The Improvement Of The
Memory, Isaac Pitman
Baddeley, A., Hitch, G. (1974), 'Working Memory'. In G. A. Bower (Ed.),
Recent Advances in Learning and Motivation, Vol.8, pp. 47-89, NY: Academic
Press
Baddeley, A., (1993) 'Working memory or working attention' in Attention:
Selection, awareness and controll: A tribute to Donald Broadbent, UK: Oxford
University Press
Baddeley, A., (2000), 'The Episodic Buffer: A new component of Working
Memory?' Trends in Cognitive Sciences, 4, 11, pp.417=423
23 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Baddeley, A., (2001), 'Is Working Memory Still Working?)' European
Psychologist, Vol.7, 2, June 2002, pp. 85-97
Baddeley, A. (2003) 'Working Memory: Looking Back And Looking Forward'
Neuroscience 4, pp. 829-839
Baddeley, A., Eysenck, M.W., Anderson, M.C., (2009) Memory, UK:
Psychology Press
Bakalar, N. (2008) 'Memory Training Shown to Turn Up Brain Power' New
York Times: Research, 29th April
Ball, K., Berch, D., Helmers, K., Jobe, J., Leveck, M., Marsiske, M., Morris, J.,
Rebok, G., Smith, D., Tennestedt, S., Unverzagt, F., Willis, S. (2002) 'Effects
of Cognitive Training Interventions' Journal of the American Medical
Association, November, 13, Vol.288, 18, pp.2271-2279
Barrouillet, P., Bernadin, S., Camos, V. (2004) 'Time constraints and resource
sharing in adults' working memory spans' Journal of Experimental
Psychology: General, 133, pp. 83-100
Beaudoin, M., Desrichard, O. (2011) 'Are Memory Self-Efficacy and Memory
Performance Related? A Meta-Analysis' Psychological Bulletin, 137, 2, pp.
211-241
Bermudez_Rattoni, F., Nunez-Jaramillo, L., Balderas, I., (2005) 'Neurobiology
of Taste-recognition Memory' Chemical Senses, 30, 1, pp. 156-157
Buckley, S. (2008) 'It is time to take memory training seriously' Down
Syndrome Research and Practice, 12, 2, pp. 105-106
Buzan, T., (1995) Use Your Memory, BBC Books
24 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Buzan, T., (2009) The Memory Book: Boost your memory year after year, UK:
BBC Active
Callaway, E. (2010) 'Skills from the mind gym don't transfer', New Scientist,
24 April, p.10
Chase, W.G., Ericsson, K.A. (1982) 'Skill and working memory' in G.H. Bower
(Ed.), The psychology of learning and motivation, 16, pp. 1-58, US: Academic
Press
Chein, J.M., Morrison, A.B. (2010) 'Expanding the mind's workspace: Training
and transfer effects with a complex working memory span task' Psychonomic
Bulletin & Review, 17, 2, pp. 193-199
Cogmed,
(2009)
'Working
Memory
Training'
(promotional
brochure),
www.cogmed.com
Cohen, J.D., Peristein, W.M., Braver, T.S, Nystrom, L.E., Neil, D.C., Jonides,
J., Smith, E.E.
(1997) 'Temporal dynamics of brain activation during a
working task' Nature, 386, 604-606
Cowan, N. (1997) 'The development of working memory', in N.Cowan (Ed.)
The Development of Memory in Childhood, UK: Psychology Press
Cowan, N., (1999) 'An embedded processes model of working memory', in
A.M.P. Shah (Ed.) Models of Working Memory, UK: Cambridge University
Press
Cowan, N., (2001) 'The magical number 4 in short-term memory: a
reconsideration of mental storage capacity' Behavioral and Brain Sciences,
24, pp. 87-185
25 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Dougall, G.J. (2009) 'A Framework for Cognitive Interventions Targetting
Everyday Memory Performance and Memory Self-Efficacy' Community
Health, 32, 1s, pp. s15-s26
Engle, R.W., (1996) 'Working memory and retreival: An inhibition resource
approach' in J.T.E Richardson, R.W. Engle, L. Hasher, R.H. Logie, E.R.
Stoltfus, R.T.Zacks, (Eds.) Working Memory and Human Cognition, US:
Oxford University Press
Ericsson, K.A. (1985) 'Memory Skill' Canadian Journal of Psychology, 39, 2,
pp. 188-231
Fairclough, S.H., Houston, M. (2004) 'A metabolic measure of mental effort'
Biological Psychology, 66, pp. 177-190
Flynn, T., Storandt, M., (1990) 'Supplemental group discussions in memory
training for older adults' Psychology and Aging, Vol.5 (2) pp.171-182
Foer, J., (2011) Moonwalking With Einstein: the Art and Science of
Remembering Everything, UK: Allen Lane
Gathercole, S.E., Brown, L., Pickering, S.J. (2003) 'Working memory
assessments at school entry as longitudinal predictors of National Curriculum
attainment levels' Educational and Child Psychology, 20, 109-122
Gathercole, S.E., Pickering, S.J., Ambridge, B., Wearing, H., (2004) 'The
Structure of Working Memory From 4 to !5 Years of Age' Developmental
Psychology, 40, 2, pp. 177-190
Gathercole, S.E. (2008) 'Working memory in the classroom' The Psychologist,
21:5, 382-385
Gould, S.J., (1981) The Mismeasure of Man, UK: Penguin
26 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Henson, R., (2001) 'Neural working memory' in J. Andrade (Ed.) Working
Memory in Perspective, UK: Psychology Press
Holmes, J., Gathercole, S.E., Dunning, D.L., (2009a) 'Adaptive training leads
to
sustained
enhancement
of
poor
working
memory
in
children',
Developmental Science, 12, 4, pp. 9-15
Holmes, J., Gathercole, S.E., Place, M., Dunning, D.L., Hilton, K.A., Elliott,
J.G., (2009b) 'Working memory deficits can be overcome. Impacts of training
and medication on working memory in children with ADHD' Applied Cognitive
Psychology, 24, 6, pp. 827-836
Hossiep, R., Hasella, M. (2010) BOMAT Standard, Standard Matrices
Bochum, Gottingen: Hogrefe
Jaeggi, S.M., Buschkuehl, M., Jonides, J., Perrig, W. (2008) 'Improving fluid
intelligence with training on working memory' PNAS Early Edition, The
National Academy of the Sciences of the USA, Feb. 2008
Johnson, B.E. (1976) What was that verse again? Memory improvement
methods for the Christian worker, Mott Media
Jonides J. (2004) 'How does practice make perfect?' Nature Neuroscience, 7,
1, pp.10-11
Klingberg, T., Forssberg, H., Westerberg, H., (2002) 'Training of Working
Memory in Children With ADHD' Journal of Clinical and Experimental
Neuropsychology, 22, 6, pp781-791
Klingberg, T., Fernell, E., Olesen, P.J., Johnson, M., Gustafson, P.,
Dahlstrom, K., Gillberg, C.G., Forssberg, H., Westerberg, H. (2005)
'Computerized Training of Working Memoy in Children With ADHD - A
Randomized, Controlled Trial' Journal of the American Academy of Child and
Adolescent Psychiatry, 44:2, 177-186
27 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Klingberg, T., (2009) The Overflowing Brain, UK: Oxford
Klingberg, T., (2010) 'Training and plasticity of working memory' Trends in
Cogntive Sciences, 14, pp. 317-324
Leake, J., (2008) 'Memory Exam as Good as an IQ Test' Sunday Times,
16.8.2009
Loisette, A., (1896) Assimilative memory, or How to attend and never forget,
USA, Funk and Wagnalls Co,
Lorayne H, Lucas J., (1974) The Memory Book US: Stein and Day
Lorayne H., Lucas J., (1986) The memory book: The classic guide to
improving your memory at work, at school and at play, US: Ballantine Books
Lovatt, P., Avons, S., (2001) 'Re-evaluating the word length effect', in J.
Andrade (Ed.) Working Memory in Perspective, UK: Psychology Press
May, J., (2001) 'Specifying the central executive may require complexity', in J.
Andrade (Ed.) Working Memory in Perspective, UK: Psychology Press
McNab, F., Varrone, A., Jucaite, A., Bystritsky, P., Forssberg, H., Klingberg,
T., (2009) 'Changes in Cortical Dopamine D1 Receptor Binding Associated
with Cognitive Training' Science, 323, Feb., pp. 800-802
McPherson, F. (2000) The Memory Key, Career Pree
Memosyne
Ltd.
(2007)
Jungle
Memory,
(on-line
training
www.junglememory.com
28 - 31
533581322
package),
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Miller, G.A. (1956) 'The magical number seven, plus or minus two: Some
limits on our capacity for processing information', Psychological Review, 6, 3,
pp. 81-97
Moody, D.E. (2009) 'Can intelligence be increased by training on a task of
working memory?', Intelligence, 37, pp.327-328
Morrison, A.B., Chein, (2011) 'Does working memory training work? The
promise and challenges of enhancing cognition by training working memory',
Psychonomic Bulletin Review, 18, pp. 46-60
Newell, A., Simon, H.A., (1956) The Logic Theory Machine - A Complex
Information Processiong System US: (Monograph) The Rand Corporation
Oberauer, K., SuB H.-M., Schulze, R., Wilhem, O., Wittman, W.W. (2000)
'Working memory capacity - facets of a cognitive ability construct' Perssonality
and Individual Differences 29, pp.1017-1045
Olesen, P.J., Westerberg, H., Klingberg, T., (2004) 'Increased prefrontal and
parietal activity after training of working memory' Nature Neuroscience, 7, 1,
pp. 75-79
Olson, I., Jiang, Y., Moore, K. (2005) 'Associative Learning Improves Visual
Working Memory Performance' Journal of Experimental Psychology: Human
Perception and Performance, 31, 5, pp.889-900
Owen, A.M, Hampshire, A., Grahn, J.A., Stenton, R., Dajani, S., Burns, A.S.,
Howard, R.J., Ballard, C.G., (2010) 'Putting brain training to the test' Nature,
465, pp. 775-778
Pearson, D.G. (2001) 'Imagery and the visuo-spatial scratchpad' in J. Andrade
(Ed.) Working Memory in Perspective, UK: Psychology Press
29 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
Pickering, S.J., Gathercole, S.E. (2001) Working Memory Test Battery for
Children, UK: Harcourt Assessment
Redick, T.S., Calvo, A., Gay, C.E., Engle, R.W. (2011) 'Working Memory
Capacity and Go/No-Go Task Performance: Selective Effects of Updating,
Maintenance and Inhibition', Journal of Experimental Psychology, 37, 2, pp.
308-324
Shannon, C.E., (1949) The Mathematical Theory of Communication. US:
University of Illinois Press
Shipstead, Z., Redick, T.S., Engle, R.W., (2010) 'Does Working Memory
Generalize?' Psychologica Belgica, 50, 3&4, pp. 245-276
Smith, E.E., Jonides, J. (1997) 'Working Memory: A View from Neuroimaging',
Cognitive Psychology, 33, pp. 5-42
Smyth, M.M., Pearson, N.A., Pendleton, L.R. (1988) 'Movement and working
memory: Patterns and positions in space' The Quarterly Journal of
Experimental Psychology Section A: Human Experimental Psychology, 40, 3,
pp. 497-514
Stine, J.M. (1997) Double your brain power: increase your memory by using
all of your brain all of the time, USA, Prentice-Hall
Sullivan, K.A., Madden, I. (2008) 'A pilot investigation of the effectiveness of a
memory improvement program on subjective and objective memory in healthy
young adults: directions for future research' Neuro Rehabilitation (in press)
Ward, G. (2001) 'A critique of the WM model' in J. Andrade (Ed.) Working
Memory in Perspective, UK: Psychology Press
Ward, J., (2010) The Student's Guide to Cognitive Neuroscience, UK:
Psychology Press -Taylor and Francis
30 - 31
533581322
Brian Apter – TopUpEdD, Student no. 0842733, 5/9/2011
White, T.L. (1998) 'Olfactory Memory: the Long and Short of it' Chemical
Senses, 23, pp. 433-441
Willis, S., Tennstedt, S., Marsiske, M., Ball, K., Ellias, J., Koepke, K., Morris,
J., Rebok, G., Unversagt, F., Stoddard, A., Wright, E. (2006) 'Long-term
Effects of Cognitive Training on Everyday Functional Outcomes in Older
Adults' Journal of the American Medical Association, December, 20, Vol.296,
23 pp.2805-2814
Young, M. N., Gibson, W., (1970) How to Develop an Exceptional Memory,
UK: Wiltshire Book Company
31 - 31
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