Brian Butterworth Institute of Cognitive Neuroscience, UCL Centre for Educational Neuroscience
Consequences of poor maths ability and poor reading ability for life chances
• More of a handicap in the workplace than poor literacy (Bynner & Parsons, 1997, Does Numeracy Matter? )
• Men and women with poor numeracy, have poorer educational prospects, earn less, and are more likely to be unemployed, in trouble with the law, and be sick (Parsons & Bynner, 2005, Does Numeracy Matter More? )
What is dyscalculia?
• Is it just being bad/very bad at maths? • No. In the same way that dyslexia is not just being very
bad at reading. • There is an underlying specific deficit that causes
learners to be very bad at maths • Though of course, there are many reasons to be bad at
maths – Lack of opportunity to learn – Inappropriate teaching – Missing lessons – Lack of numerical activities in the home – Cognitive disabilities
I’ll return to what dyscalculia really is
• But first we need to understand the cognitive basis of arithmetic
• And then the neural basis of arithmetic
Arithmetic is about sets and their numerosities • Sets
– A set has definite number of members (“numerosity”) – Adding or taking away a member changes the numerosity – Other transformations conserve numerosity – Numerical order can be defined in terms of sets and subsets – Arithmetical operations can be defined in terms of operations on sets
• We learn about counting and arithmetic using sets – And about the meaning of number terms
7
Arithmetical development depends on numerosity processing capacity
For which there are very simple tests
Enumerating sets: the ‘size effect’
0
500
1000
1500
2000
2500
1 2 3 4 5 6 7 8 9Number of dots
Rea
ctio
n tim
e
subitizing
counting
Data from Butterworth et al, 1999
Comparing numerosities: the ‘distance effect’
Data from Butterworth et al, 1999
Distance
3 8Symbolic
Non-Symbolic
3 8
Taller number?
We can use these tests child to assess individual difference in the ability to
process numerosities
These are not tests of arithmetic, but they could be tests of the cognitive prerequisite for
learning arithmetic
Not norms but cluster analysis
• Children improve with age. How to assess whether they improve relative to peers?
• Is a learner always in the same cluster? – A cluster is not defined by an arbitrary criterion (e.g. ≤5%, 10% ≤1 SD,
2SD, etc) but what the data actually looks like
• We used clusters based on parameters of the dot enumeration measure, adjusted for basic Reaction Time
• Can this simple measure predict which children will have trouble learning arithmetic?
• If so, it will mean that the capacity to enumerate sets is essential to learning arithmetic
Melbourne longitudinal study
159 children from 5½ to 11, tested 7 times, over 20 cognitive tests per time;
item-timed calculation, dot enumeration & number comparison (adjusted for simple RT) at each time,
Raven’s Coloured Progressive Matrices (IQ)
Reeve, Humberstone, Reynolds & Butterworth, 2012, J Experimental Psychology: General
Enumeration times by age & cluster
0
2000
4000
6000
8000
1 2 3 4 5 6 7 8
RT in msecs
Number of Dots
6 years 7 years8.5 years 9 years11 years
0
2000
4000
6000
8000
1 2 3 4 5 6 7 8
RT in msecs
Number of Dots
6 years 7 years8.5 years 9 years11 years
0
2000
4000
6000
8000
1 2 3 4 5 6 7 8
RT in msecs
Number of Dots
6 years 7 years8.5 years 9 years11 years
SLOW MEDIUM FAST
Cluster at K predicts age-appropriate arithmetic to age 10 yrs
0
20
40
60
80
100
Slow Medium Fast
Single-Digit Addition at 6 yrs
Slow Medium Fast
Conclusion
• There’s a small cluster (about 7% in this sample) with poor ability to enumerate sets: a core deficit in numerosity processing
• This core deficit persists from kindergarten to 11 years • It predicts who will and who will not have trouble learning
arithmetic at least to the age of 11 years • Implication: use this test in kindergarten or year 1 so that
you know which children are likely to have difficulty
Core deficit in numerosity processing also predicts how learners do arithmetic
Strategy change in the first two years of school
Arithmetical brain
Read Retrieve Compute
RETRIEVE+RECRUIT VS READ Zago et al, 2001, Neuroimage
SUBTRACTION+MULTIPLICATION VS READ Andres et al, 2011, Neuroimage
The arithmetical brain
The calculation network Zago et al, Neuroimage, 2001
Left hemisphere: INTRAPARIETAL SULCUS ANGULAR GYRUS
Right hemisphere INTRAPARIETAL SULCUS)
Left hemisphere: FRONTAL LOBE
IPS processes NUMEROSITIES
Task: more green or more blue?
Castelli, Glaser, & Butterworth, 2006, PNAS
Discrete Analogue
Discrete (how many) activations minus analogue (how much) activations à Numerosity sensitive activations
Activation in the INTRAPARIETAL SULCI depends on the ratio of green and blue rectangles: closer > farther (e.g. 11vs 9 >14 vs 6)
Case JB
• 9years 7 months old, Right Handed male. Normal in all school subjects except maths, which he finds impossible. Not dyslexic. Counts up to 20 slowly. Can read and write numbers up to 3 digits.
• Failed Britsh Abilities Scale arithmetic questions • Knows that 4 is the next number after 3 (has a sense of
ordinality) • Believes that 3+1 is 5 • Dot enumeration: 1-3 accurate. Guesses larger numbers • Cannot say which of two numbers is bigger
What it’s like for the dyscalculic learner(9yr olds)
Moderator: How does it make people feel in a maths lesson when they lose track?
Child 1: Horrible. Moderator: Horrible? Why’s that? Child 1: I don‘t know. Child 3 (whispers): He does know. Moderator: Just a guess. Child 1: You feel stupid.
Focus group study (lowest ability group) Bevan & Butterworth, 2007
What it’s like for the dyscalculic learner
Child 5: It makes me feel left out, sometimes. Child 2: Yeah. Child 5: When I like - when I don’t know something, I
wish that I was like a clever person and I blame it on myself –
Child 4: I would cry and I wish I was at home with my mum and it would be - I won’t have to do any maths -
What it’s like for their teacher
• KP: … they kind of have a block up, as soon as we get to starting to do it. Then they seem to just kind of phase out.
• ML1: In a class of thirty I’ve got six. You’ve got a lot of problems. And when I’m on my own, I don’t – I really feel very guilty that I’m not giving them the attention they need.
• JL: …lots of times they’re trying to cover it up ... they’d rather be told off for being naughty than being told off that they’re thick.
So, if there a deficit in numerosity processing is at the core of dyscalculia
Then there should be abnormalities in the INTRAPARIETAL SULCI
Isaacs et al, 2001
Rotzer et al 2008 NeuroImage
Abnormal structure in numerosity network in dyscalculics
Isaacs et al, 2001, Brain Ranpura et al in prep
Castelli et al, 2006, PNAS
Abnormal activations in the IPS
NSC – close NSF - far
12 year olds: dyscalculics and matched controls
Price et al, 2007, Current Biology
Numerosity representa/on, manipula/on
Arithme(c fact retrieval
ARITHMETIC
Number Symbols
Fusiform Gyrus
Angular Gyrus
Intraparietal Sulcus
Parietal lobe
Occipito-‐ Temporal
Biological
Cogni(ve
Behavioural Simple number tasks
Gene(cs
Frontal lobe
Concepts, principles, procedures
Analogue magnitudes
Educa(onal context
Prac(ce with numerosi(es
Exercises on manipula(on of
numbers
Experience of reasoning about
numbers
Exposure to digits and facts
Prefrontal Cortex
Summary of the neuroscience
From neuroscience to education
From diagnosis to educational remedy?
No clear logical pathway
à use established pedagogical principles
à use ideas from best practitioners
à use technology to capture and test ideas
DfE 2014 • Search for ‘Dyscalculia’ on the DfE website and what do you get? • Guidance: Employing disabled people and people with health condi(ons • 6.1 Suppor/ng people with hidden impairments
– The Hidden Impairment Toolkit offers hints and (ps on how employers can beRer support people with hidden impairments such as:
– Au(s(c Spectrum condi(ons including Asperger Syndrome – ARen(on Deficit Hyperac(vity Disorder – Dyslexia – Dyspraxia – Dyscalculia – speech and language impairments – The
Do It Profiler gives resources for employers to help them to beRer understand the issues around specific learning disabili(es and their relevance to the workplace.
• Hidden Impairment Toolkit: Following a recent internal review of our group we are currently upda(ng our resources for employers which includes our website.
• Do It Profiler: Also available is a free guide, developed by interna(onal experts in the field, to informa(on for employers and employees on hidden impairments, including:
– Dyslexia – Dyspraxia – ADHD – Au(sm Spectrum Condi(ons – Speech, language and communica(on impairments – Mental health condi(ons including anxiety, depression, schizophrenia, bipolar disorder, personality disorder – This includes an easy to use guide to assist with making reasonable adjustments in the workplace.
Official definitions ✤ DSM IV Mathema/cs disability.
✤ The child must substan(ally underachieve on a standardized test rela(ve to the level expected given age, educa(on, and intelligence and must experience disrup(on to academic achievement or daily living
✤ DSM 5 315.1 Learning disabili/es ✤ A persistent difficulty learning academic skills for at least 6 months despite
interven(on targe(ng the area(s) of difficulty. – Specifier
• In number sense, fact and calcula(on, and in mathema(cal reasoning – Severity: Mild, Moderate or Severe – The academic and learning difficul(es occur in the absence of:
• Intellectual Disabili(es, Visual or hearing impairments, Mental disorders (e.g. depression, anxiety, etc.), Neurological disorders, Psycho-‐social difficulty, Language differences, Lack of access to adequate instruc(on
– DSM IV used an IQ discrepancy criterion. DSM 5 does not, except that there is an exclusionary rule – no very low IQs (e.g. <70)
✤ Interna/onal Classifica/on of diseases (ICD) 10 ✤ Specific disorder of arithme/cal skills. Involves a specific impairment in arithme(cal
skills that is not solely explicable on the basis of general mental retarda(on or of inadequate schooling. The deficit concerns mastery of basic computa(onal skills of addi(on, subtrac(on, mul(plica(on, and division rather than of the more abstract mathema(cal skills involved in algebra, trigonometry, geometry, or calculus.
Italy 2010. Law 170 • New regula(ons concerning specific disorders of learning. • Ar(cle 1.1. The present law recognizes dyslexia, dysgraphia,
dysorthographia and dyscalculia as Specific Learning Disabili(es… They manifest themselves in cases of adequate cogni(ve capaci(es, and in absence of neurological or sensory deficits. Yet, they cons(tute an important limita(on for daily ac(vi(es.
• Ar(cle 1.5. The present law refers to dyscalculia as a specific deficit which manifests itself as a difficulty in grasping the automa(sms of calcula(on and number processing.
• Ar(cle 2 states among other things, that there will be appropriate teaching to realize poten(al, a reduc(on in social and emo(onal consequence, train teachers appropriately, make people aware of the problem, promote early diagnosis and rehabilita(on, and ensure equal opportuni(es to develop social and professional capaci(es.