Working Memory
&
ADHD
Prof Maurice Place
maurice.place@northumbria.ac.uk
Disclosure:
Currently member of the speakers panel of
AstraZeneca
Eli Lilly
Janssen Cilag
Shire
The executive function
comprises those mental functions involved in
formulating goals,
planning how to achieve them,
carrying out the plans,
and revising those plans in the event of failure
(Lezak, 1982)
The executive function
comprises those mental functions involved in
formulating goals,
planning how to achieve them,
carrying out the plans,
and revising those plans in the event of failure
Executive functioning becomes engaged
for the more high level tasks
Working Memory
a dynamic, short-term storage
of information to be actively used or manipulated
and is a localised function
(Alloway et al., 2006)
How Memory Works
Sensory inputs are held through transient functional
changes in the strength of
pre-existing synaptic connections
The basal ganglia and pre-frontal cortex analyze
sensory inputs and decide if they're worth
remembering
How Memory Works
Sensory inputs are held through transient functional
changes in the strength of
pre-existing synaptic connections
The basal ganglia and pre-frontal cortex analyze
sensory inputs and decide if they're worth
remembering
If SO - create stable and permanent changes in
neural connections throughout the brain by the
synthesis of new protein and the growth of new
connections.
(Malenka &Nicoll 1999; Kandel 2000; McNab & Klingberg 2007)
How Memory Works
Sensory inputs are held through transient functional
changes in the strength of
pre-existing synaptic connections
The basal ganglia and pre-frontal cortex analyze
sensory inputs and decide if they're worth
remembering
If SO create stable and permanent changes in neural
connections throughout the brain by the synthesis of
new protein and the growth of new connections.
Especially during sleep
(Diekelman & Born 2010)
Short-term memory is the term for
short-term storage of information
with no manipulation or
organizational element
Working memory is
the structures and processes
used for temporarily storing
and manipulating information.
Professionals use working memory for…
◦
◦
◦
◦
◦
Getting to work on time
Meeting deadlines at work
Multi-tasking and prioritizing
Working effectively in pressure situations
Remembering important names and phone
numbers
◦ Interaction with co-workers
◦ Writing emails, memos, or summaries
Rehearsal
Storage
(Baddeley 2000)
Anatomical and imaging studies indicate
Working Memory use frontal-parietal
circuitry
(Paulesu et al., 1993; Smith & Jonides 1998)
The processes are significantly dependent
upon dopamine
(Goldman-Rakic 1998).
Children who have been treated for PKU
tend to have a deficit in prefrontal dopamine
(Diamond 2007)
These children have Working Memory problems
even when the primary symptoms
of the disorder are successfully treated
(Topakas et al., 2010; Bik-Multanowski et al., 2011)
Children who have been treated for PKU
tend to have a deficit in prefrontal dopamine
(Diamond 2007)
These children have Working Memory problems
even when the primary symptoms
of the disorder are successfully treated
(Topakas et al., 2010; Bik-Multanowski et al., 2011)
Similarly
patients with Fragile X
show specific deficits in Working Memory
(Hooper et al., 2008;
Cornish et al., 2009;
Baker et al., 2011)
Working Memory deficiency plays
a central role in schizophrenia
(Lewis et al., 2005; Lewis & Gonzalez-Burgos, 2006).
Memory impairment is one of the earliest
and most consistent manifestations of the disease
Working Memory impairment is stable over time
and is independent of psychotic symptoms
(Zhang & Luck 2008; Gold et al., 2010)
Working Memory deficiency plays
a central role in schizophrenia
(Lewis et al., 2005; Lewis & Gonzalez-Burgos, 2006).
Memory impairment is one of the earliest
and most consistent manifestations of the disease
Working Memory impairment is stable over time
and is independent of psychotic symptoms
(Zhang & Luck 2008; Gold et al., 2010)
It probably uses GABA pathways
(Timofeeva & Levin 2011)
Working Memory performance is heritable
(Ando et al., 2001; Chen et al., 2009)
And although no genetic correlation between
gray matter density
and Working Memory performance,
inheritance of white matter structure
is likely to be one of the mechanisms of
genetic transmission
(Karlsgodt et al., 2010)
Indicators that a working memory needs improving

Frequently late to work

Underestimates time required to complete a task

Problems breaking a project down into manageable
steps or dealing with more than one task at a time

Can’t concentrate under pressure; prone to panicking

Can’t remember clients’ names or numbers after
meeting them or hanging up the phone

Difficulty creating neat and coherent emails,
memos, or summaries
Working Memory
assessed using simple cognitive tasks
4 aspects of memory
 verbal and visuo-spatial storage (simple span)
 verbal and visuo-spatial processing
and storage (complex span)
Working Memory
verbal short term memory
– ability to hold verbal information in memory for a short period
…eg new telephone number
…problems mean slow to acquire new vocabulary
verbal working memory
– to hold and manipulate verbal information
…links to academic ability including literacy and numeracy
visuo-spatial short term memory
– holding visuo-spatial information
….problems with mathematics, and word problems.
visuo-spatial working memory
– to hold and manipulate visuo-spatial information
…links to academic ability including literacy and numeracy
and is predictor of poor scholastic attainment.
Working Memory
assessed using simple cognitive tasks:
WMI of the WAIS or WISC
Automated Working Memory Assessment
(Alloway, 2008)
Verbal STM/Verbal simple span tasks
839251
839251
DIGIT RECALL
Visuo-spatial STM/
Visuo-spatial simple span tasks
MAZES MEMORY
Visuo-spatial STM/
Visuo-spatial simple span tasks
MAZES MEMORY
Visuo-spatial STM/
Visuo-spatial simple span tasks
MAZES MEMORY
Verbal STM/Verbal Complex span tasks
chairs
lay eggs
false
bananas
have teeth
false
LISTENING RECALL TASK
Verbal STM/Verbal Complex span tasks
chairs
lay eggs
bananas
have teeth
false
false
eggs, teeth
LISTENING RECALL TASK
Visuo-spatial WM/Complex visuo-spatial tasks
SPATIAL SPAN TASK
Visuo-spatial WM/Complex visuo-spatial tasks
SPATIAL SPAN TASK
Visuo-spatial WM/Complex visuo-spatial tasks
SPATIAL SPAN TASK
Visuo-spatial WM/Complex visuo-spatial tasks
SPATIAL SPAN TASK
Visuo-spatial WM/Complex visuo-spatial tasks
SPATIAL SPAN TASK
Associations with Specific Disorders
Specific Working Memory problems
evident in various disorders:
PKU
Schizophrenia
Specific Working Memory problems
evident in various disorders:
PKU
Schizophrenia
Depression:
deficits in working memory
for both visual and verbal material
even in young adulthood
(Castaneda et al., 2008)
Deficits which appear to persist
even in the remitted state
(Hasselbalch et al., 2010)
Specific Working Memory problems
evident in various disorders:
PKU
Schizophrenia
Depression
PTSD:
(Yehuda et al., 1995;Vasterling et al., 2002;
Liberzon & Sripada, 2008).
with structural imaging
correlating with predicted deficits
(Liberzon & Sripada, 2008;
Woodward et al., 2009).
Specific Working Memory problems
evident in various disorders:
PKU
Schizophrenia
Depression
ODD:
substantial deficits in information storage
and verbal and spatial domains
of Working Memory.
- Verbal WM less damaged in ADHD
(Rhodes et al 2012)
In childhood abuse:
emotional forms of abuse/neglect show
visual memory and emotional processing deficits.
sexual abuse most associated with
spatial working memory deficits,
Not seen in other types of abuse.
physical forms of abuse/neglect most strongly
linked to processing speed
and emotional processing deficits.
(Gould et al., 2012)
Working Memory Capacity & Learning
Working Memory Capacity & Learning
Important for successful learning
in individual classroom activities
(Gathercole & Alloway, 2008)
Working Memory Capacity & Learning
Associated with reading and mathematics ability
(Gathercole & Pickering, 2000; Geary et al., 2004)
Working Memory Capacity & Learning
One specific function important in reading
comprehension is processing speed.
(Willcutt et al. ,2001; Laasonen et al., 2009)
Commonly associated with ADHD
with a correlation of 0.7 between the two disorders.
(Shanahan et al., 2006)
Working Memory Capacity & Learning
“Most of the time when I’m reading assignments
In my textbooks, I’m just licking the words rather
than chewing them. That’s why I have to keep
going back to read it all over again.”
(Brown et al., 2011)
Working Memory Capacity & Learning
IN ADHD can be relatively situation specific:
little impairment in ability when doing tasks
which hold strong personal interest
or anxiety for them,
though show significant impairment
in most other situations.
(Brown 2009; Anmarkrud & Braten 2009)
Working Memory and Academic Activity
Age
Pre-school
Working memory is
crucial for...
Learning the
alphabet
Indicators that a working memory
needs exercise
Unwillingness to learn
Completing a puzzle
independently
Infant school
Junior school
Senior school
College
Understanding
textual content
(reading
comprehension)
Inability to understand what is
read
Mental arithmetic
Problems memorizing the
multiplication table
Completing
homework
independently
Can’t complete homework
without parental supervision
and direction
Complex math
problems, especially
word problems
Inability to grasp/break down
word problems
Writing essays
Difficulty writing neat, coherent
essays
Studying for an
exam
Constantly procrastinates;
panics the night before an exam
Participation in
group projects
Doesn’t listen or participate
during a group project
Keeping
focus/interest
during a lecture
Difficulty remaining attentive
during lectures
Working Memory Capacity & Learning
Message from the research:
low working memory = educational underachievement
Working Memory & ADHD
What are the Academic and Educational
Characteristics of Children with ADHD?
Children with ADHD show
significant academic underachievement
poor academic performance
educational problems
(Hinshaw, 1992;
Fergusson & Horwood 1995;
Rapport et al., 1999;
Sayal 2008;
Galéra et al., 2009)
What are the Academic and Educational
Characteristics of Children with ADHD?
IQ - compared with controls score on average
within the normal range
(Biederman et al., 1996)
BUT score significantly lower on reading and
arithmetic achievement tests than controls.
(Biederman et al., 1996)
Children with ADHD are 4 to 5 times more likely
need special educational services.
(LeFever et al., 2002; Jensen et al., 2004)
What are the Academic and Educational
Characteristics of Children with ADHD?
Academic difficulties begin early in life.
Symptoms are common in children aged 3 to 6 years,
(Gadow et al., 2001)
preschool children with ADHD are more likely to be
behind in basic academic readiness skills.
(Mariani & Barkley 1997; DuPaul, et al., 2001)
have impaired handwriting performance
characterized by illegible written material
and/or inappropriate speed of execution
(Racine et al., 2008)
What are the Academic and Educational
Characteristics of Children with ADHD?
In adolescence:
achieve lower ratings on all school subjects
have lower class rankings
perform poorly on standardized
academic achievement tests
(Gittelman et al., 1985;
Barkley et al., 1990;
Weiss et al., 1999).
x2 likely to repeat a grade
(Currie & Stabile 2006; Beiderman et al., 2006)
x2 - 4 to have lower than expected grades
(Todd et al., 2002)
What are the Academic and Educational
Characteristics of Children with ADHD?
School histories indicate
persistent problems in social participation
more years to complete high school
lower rates of college attendance
lower rates of college graduation
(Mannuza et al., 1993;
Weiss et al., 1999;
Barkley 2002).
What are the Academic and Educational
Characteristics of Children with ADHD?
In College
relative to other students
have lower GPAs
more academic concerns
depressive symptoms
social concerns
emotional instability
and substance use.
BUT most said were coping.
(Blase et al., 2009)
What are the Academic and Educational
Characteristics of Children with ADHD?
longitudinal studies into young adulthood
Initial symptoms of hyperactivity
distractibility
impulsivity
aggression
tend to decrease in severity over time
BUT remain present and increased in
comparison to controls
(Weiss et al., 1999).
For instance….
26 ADHD individuals and 31 controls
(paired for gender, age, & intelligence)
Using mathematics and language scores
academic underachievement was
2.98 times higher in students with ADHD
(Pastura et al., 2009)
Ethnically diverse cohort of 823 assessed at 6 years for
behavioural problems and IQ
and at 17 years of age for academic achievement in
math and reading, and other parameters.
Ethnically diverse cohort of 823 assessed at 6 years for
behavioural problems and IQ
and at 17 years of age for academic achievement in
math and reading, and other parameters.
Attention problems predicted poor maths and reading
achievement with little benefit from intervention.
Whereas reducing externalizing and internalizing
problems materially reduced academic problems.
(Breslau et al., 2009)
What are the Academic and Educational
Characteristics of Children with ADHD?
3 main groups of outcome as young adults:
(1) approximately 25% eventually function
comparably to matched normal controls
(2) the majority show continuing
functional impairment,
limitations in learning and applying knowledge
restricted social participation,
particularly poor progress through school
(3) about 25% develop significant, severe
problems, including psychiatric and/or
antisocial disturbance
(Hechtman 2000)
Academic difficulties associated with
inattention are cross-cultural and not
specific to the Western countries.
(Norvilitis et al., 2010)
People with ADHD have difficulties with:
planning, organization,
reasoning,
response inhibition,
decision-making,
set-shifting
working memory
(Tranel et al., 1994;
Pennington and Ozonoff 1996;
Barkley 1997;
Geurts et al., 2004)
ADHD symptom severity is associated with
magnitude of impairment in executive functions
BUT this relationship can be obscured by the
presence of comorbid disruptive disorders.
(Barnett et al., 2009)
The Impact of Medication
The Impact of Medication
Methylphenidate improves the transmission of
signal versus noise
by reducing response to the noise.
AND improves concentration by
increasing dopamine levels in
fronto-striatal pathways
(Williams & Goldman-Rakic, 1995).
The Impact of Medication
Neuroimaging studies have also shown
methylphenidate blocks up to 70% of transporters
in these pathways – improving dopamine availability
(Krause 2008)
Continued use of stimulants tends to normalise deficits
(Shaw et al., 2009;
Bledsoe et al., 2009;
Nakao et al., 2011)
The Impact of Medication
medication improves academic productivity as
indicated by
improvements in the quality of note-taking
scores on quizzes and worksheets
the amount of written-language output
homework completion.
(Evans et al., 2001)
methylphenidate increases in dopamine with
improved interest and motivation to do maths tasks
(Volkow et al., 2004)
The Impact of Medication
However, stimulants are not associated with
normalization of skills in the domain
of learning and applying knowledge.
(Rapport et al., 1994)
Early Childhood Longitudinal Study
1195 children were tested at 5 points:
compared the academic performance of treated
with untreated children at each testing node.
medicated gained 2.9 points in mathematics
performance between the first and final testing
reading performance medicated gained 5.4 points
above unmedicated
Early Childhood Longitudinal Study
1195 children were tested at 5 points:
compared the academic performance of treated
with untreated children at each testing node.
medicated gained 2.9 points in mathematics
performance between the first and final testing
reading performance medicated gained 5.4 points
above unmedicated
Despite this improvement the performance
of the medicated children with ADHD
lagged their peers without ADHD.
(Scheffler et al., 2009)
177 ADHD effectively medicated
vs 95 untreated ADHD
and 101 normal controls.
Neuro Cognitive Index
- computed as the average of the z scores of five domains (memory,
psychomotor speed, reaction time, complex attention,
and shifting attention flexibility)
untreated ADHD patients perform 15%
lower than normals.
177 ADHD effectively medicated
vs 95 untreated ADHD
and 101 normal controls.
Neuro Cognitive Index
- computed as the average of the z scores of five domains (memory,
psychomotor speed, reaction time, complex attention,
and shifting attention flexibility)
untreated ADHD patients perform 15%
lower than normals.
However, treated ADHD patients perform 10%
lower than normals.
(Gualtieri & Johnson 2008)
The Impact of Medication
In longitudinal studies
subjects consistently demonstrate poor outcomes
compared with controls
whether or not they receive medication.
(Gittelman et al., 1985;
Barkley et al., 1990;
Hechtman & Greenfield 2003;
Fischer et al., 2002;
Loe & Feldman 2007;
Powers et al., 2008)
The Impact of Medication
and in UK studies:
Despite medication, ADHD
association with poor attainment in GCSE’s
(Daley et al., 2009)
The Impact of Medication
"Given their well-established benefit for
increasing attention and concentration, it
seems counterintuitive that ADHD
medications are not more effective in
improving academic and occupational
attainment,"
(Advokat 2009)
Anatomical and imaging studies indicate
Working Memory use frontal-parietal
circuitry
(Paulesu et al., 1993; Smith & Jonides 1998)
Anatomical and imaging studies indicate
Working Memory use frontal-parietal
circuitry
(Paulesu et al., 1993; Smith & Jonides 1998)
there are only few dopamine transporters in the
prefrontal cortex
probable that dopamine uptake in this part
of the brain is via noradrenaline sites.
(Nutt & Fone 2005)
BUT consistency-impulsivity
managed through
noradrenaline pathway
(Sweitzer et al., 2006)
methylphenidate has only a modest impact
upon noradrenaline
(Berridge & Waterhouse, 2003)
IN ANIMALS - greater enhancement of
working memory function is achieved
with a2 noradrenaline agonists
(Arnsten, 2001).
SO methylphenidate
increases dopamine which improves
concentration and some cognitive elements
BUT working memory more dependent
upon noradrenaline pathways
in prefrontal cortex
SO methylphenidate alone will
not greatly improve working memory
How do children with ADHD
compare with children with
low working memory
on testing?
HMS Trincomalee, built in Bombay for the Admiralty in 1817
the oldest ship afloat in the UK
The monkey won on a “free bananas” platform
Working memory comparisons
(Holmes et al., 2009)
Improving Working Memory
Robo Memo
A computerised training programme developed
by Klingberg et al. (2002)
Does it work?
Hartlepool Study (1)
Participants
42 children, aged 8-11 years,
with low working memory
◦ Identified via routine screening of 345 children
on two verbal wm tasks (Listening Recall and
Backward Digit Recall)
◦ Scores <86 on both tasks (bottom 15th centile)
Two groups
◦ Adaptive, standard version of training
programme
 training at maximum span level
◦ Non-adaptive, control condition
 training at fixed span level of 2
(Holmes et al., 2009)
Working Memory Training
working on memory tasks on a computer
20 minutes
everyday for 20-25 days
Results from non-adaptive
*
Results from adaptive
**
**
**
**
Working Memory Training
…and at 6 mth follow-up
Results from adaptive Follow up
**
**
**
**
IQ, Reading & Maths Scores - adaptive
Pre-training
Post-training
6mth followup
Measure
M
SD
M
SD
M
SD
Verbal IQ
88.73
11.14
90.86
11.52
92.78
9.10
Performance IQ
88.05
13.09
90.68
12.96
87.11
9.07
Reading
83.68
12.35
83.00
15.06
82.83
14.1
Mathematics
84.27
12.28
85.68
12.70
89.94*
9.88
Following inst.
14.45
4.02
18.27**
4.37
16.5*
3.82
No significant improvements for non-adaptive group
Hartlepool Study (2)
Impact of Medication & Robo Memo
on Working Memory in children with ADHD
Participants:
◦ 25 children (21 boys, 4 girls), clinical diagnosis
◦ of ADHD-C
◦ receiving quick release stimulant medication
(methylphenidate n=22, dexamfetamine n=3)
◦ aged 8-11 years
◦ diagnosis for at least 6 months
◦ no co morbid ASD
(Holmes et al., 2010)
Effect of medication on IQ
Effects of medication on working memory
**
Research on Working Memory & Medication
Stimulant medication mainly improves
visuo-spatial simple span tasks
(Bedard et al., 2004)
Does RoboMemo
make a difference?
Effects of medication and training on
working memory
**
**
**
**
*
**
**
Effects of training on behaviour ratings
On Meds
Post training
(+ on meds)
Inattentivity (teacher)
69.84 (23.33)
58.21 (20.27)**
Hyperactivity (teacher)
81.15 (21.69)
70.31 (23.87)*
Working memory problems (child)
17.60 (5.72)
13.25 (6.00)**
Sustainability of training effects – 6 mth follow-up
**
**
**
**
Working Memory Intervention
◦ Significant gains in non-trained working memory
tasks, which extended across all four aspects of
working memory. Substantial increases in scores
(low-average to average range).
◦ Significant reduction in ratings of problem
behaviours
◦ No effect on IQ
Unlikely to result from practice effect
◦ Comparison group showed no test re-test effect
◦ Consistent gains in both the repeated and nonrepeated AWMA tasks in the ADHD group
SO:
Working memory deficits associated with ADHD
can be overcome by two different interventions
RoboMemo intervention led to more generalized
gains in WM, and reductions in problem behaviours
Medication led to specific gains in visuo-spatial WM,
and improves concentration
and improves academic productivity
(Holmes et al., 2010)
How is training enhancing working memory?
there are only few dopamine transporters in
the prefrontal cortex
probable that dopamine uptake in this part
of the brain is via noradrenaline sites.
(Nutt & Fone 2005)
How is training enhancing working memory?
SO not a high density of dopamine receptors in
prefrontal cortex
Training changes the density of prefrontal
& parietal cortical dopamine D1 receptors.
(McNab et al., 2009)
may stimulate the development of WM strategies
that compensate for weaknesses in basic processes
(Holmes et al., 2010)
The Research Team
Joni Holmes
Senior Lecturer in Experimental Psychology
Maurice Place
Professor of Child & Family Psychiatry
Torkel Klingberg Professor in Cognitive Neuroscience
Joe Elliott
Professor of Education
Sue Gathercole
Unit Director,
Professor of Cognition & Neuropsychology
Working Memory
&
ADHD
Prof Maurice Place
maurice.place@northumbria.ac.uk
General classroom advice
children with ADHD
are more likely to complete more problems
and complete them accurately
when high levels of engaging stimuli
are included within the task.
(Jitendra et al 2008)
children with ADHD
are more likely to complete more problems
and complete them accurately
when high levels of engaging stimuli
are included within the task.
(Jitendra et al 2008)
Pacing of tasks with periods to release energy
Clarity of goals
Instant feedback
Novel & rapidly changing rewards
children with ADHD
are more likely to complete more problems
and complete them accurately
when high levels of engaging stimuli
are included within the task.
(Jitendra et al 2008)
Pacing of tasks with periods to release energy
Clarity of goals
Instant feedback
Novel & rapidly changing rewards
Time out DOES NOT work
1. Draw or create vivid pictures depicting information that
needs to be memorized.
Since memory is enhanced by exaggeration, emotion, action,
and color, the more ridiculous and detailed the image, the
better.
2. Teach memory strategies.
Such as mnemonics e.g. Dead Monsters Smell Bad (steps for
long division: divide, multiply, subtract, bring down).
3. Create acrostics or whole sentences.
“Every Good Boy Does Fine” is an excellent way to help recall
the sequence of lines in the treble clef (EGBDF).
4. Try melody and rhythm to teach a series or sequence.
There are raps, rhymes, and songs to help attention deficit
students memorize multiplication tables, days of the week, etc.
5. Use songs specially created to teach content.
Musically Aligned (musicallyaligned.com) creates music and
lyrics geared to teach a science curriculum. For physical
science, there are songs like “Electromagnets” and “Heat,
Light, and Motion.” For teaching concepts in life science, there
are “Food Chain Gang” and “Decomposers.”
6. After the lesson, have ADHD students list the things they
remember.
Ask them to do so as fast as they can, to increase memory
recall.
(Sandra Rief 2009)
Improved by reading interventions focused on basic skills
e.g., decoding – such as activities to promote
phonological awareness and alphabetic understanding
(Blachman et al 2000).
and maths strategies
e.g. problem solving using schema-based instruction
(Jitendra et al 2007).
And strengthened by
Peer mediated interventions
Computer assisted instruction
(Jitendra et al 2008)
Task modification and varying classroom function
(Daley & Birchwood 2010)
Teaching parents homework strategies
(Raggi & Chronis 2006).