Brian Butterworth is in the Institute of Cognitive Neuroscience at University College London, where he is currently working on the neuroscience and the genetics of mathematical abilities and disabilities. He led two European networks, Neuromath and Numbra, that promoted multidisciplinary research on mathematical cognition. He founded the Centre for Educational Neuroscience. He holds professorial positions at National Chengchi University, Taiwan, and at Melbourne University, Australia. He was elected Fellow of the British Psychological Society in 1993, and Fellow of the British Academy in 2002.
His popular science book, The Mathematical Brain (1999) was a best seller. The Dyscalculia Screener (2003) revolutionized the identification of this specific learning disability. His most recent books include Dyscalculia: from Science to Education (2019), and Can fish count? What animals reveal about our uniquely mathematical minds (March 2022).
How did you became interested in learning difficulties?
It started with studies of neurological patients, initially with difficulties in language and speech, but later with selective deficits – or sparing – of numerical abilities. We confirmed earlier studies that showed the left parietal lobe was the core brain region for numerical processing. If it was damaged, then the patient would have difficulties with numbers, and if it was spared, then even if other cognitive capacities – such as language or memory – we affected, numerical abilities could remain intact. I then asked, first, why was this brain region key? Second, how does it develop and could abnormal development lead to numerical disabilities, ‘dyscalculia’? Third, are there evolutionary roots to this region’s numerical capacities.
Can you give us an overview of your work?
In 2003, I published the first standardised test for developmental dyscalculia (The Dyscalculia Screener). This is a condition roughly analogous to dyslexia (see previous posts on this series, Kathy Rastle, Catherine McBride and Cathy Magee), that makes arithmetical understanding difficult and learning arithmetic a real struggle, even for highly competent individuals, just as dyslexia makes learning to read difficult. We are now developing a new test for dyscalculia which we hope will be more accurate in distinguishing dyscalculia from all the other causes of poor arithmetic.
The basic idea is that the inherited parietal lobe system for processing numerical information is inefficient. This is very easy to assess. Participants are asked to provide the number of dots in a display as quickly as possible, usually by saying the number. Dyscalculics are slower and less accurate than typical developers.
We have created schemes for teachers (Dyscalculia Guidance, with Dorian Yeo), and digital games. Our games can be used in the classroom supervised by teachers, or at home unsupervised. The games are based on helping learners understand the relationship between sets and operations on sets (such as set union) and numbers and operations on numbers (such as addition). These games are highly effective in improving understanding in dyscalculic learners, and also in typical early learners.
People are born dyscalculic, and the handicap persists into adulthood, though it is possible that appropriate early intervention can help significantly. We think that most dyscalculics inherit the condition, and we are now looking at candidate genes that could be involved.
What are your most recent and exciting results?
I think that are game results are very exciting. They show a way in which dyscalculic learner can be helped, even without the support of highly-trained teachers. Unlike the thousands of maths games available online, ours have been properly evaluated compared with appropriate controls. They also depend on learners constructing solutions rather than selecting them from a list.
Another exciting development has been my work with fish. Here we can explore genetic variants to see which are relevant to fish numerical abilities. Yes, fish can count, and small fish need to be able to do so in order join the larger shoal and thereby reduce the risk of predation. My colleagues have identified a brain system implicated in numerical discrimination, and we are looking forward to linking both behaviour and neural activity to genes.
What do you think are the main challenges in this research field?
The main challenge is to get governments and educational authorities to recognised dyscalculia as a distinct specific learning disability, like dyslexia or autism. It is recognised in the US and Italy, but not yet in the UK. With recognition should come help for sufferers, and better funding for research.
What are the most pressing research priorities?
Although dyscalculia is due to a core deficit in the ability to represent the numbers of objects in a set, it will present in many different ways depending on the learner’s other cognitive abilities and on their experience of numbers both formally, in school, and informally at home. We need a more holistic way of characterising the strengths and weaknesses of individual learners to design interventions appropriately.
Second, we need to understand better the genetic and neuronal bases of dyscalculia. We know from twin studies that there is a genetic basis for numerical abilities and disabilities, but we don’t which genes are involved. Neuroimaging studies have so far provided a rather confusing picture, partly because studies use different criteria for dyscalculic learners. Standardisation here would help clarify the situation. The most robust studies reveal differences in the structure and functioning of the left parietal lobe.
Third, longitudinal studies of brain changes as the learner learns arithmetic would help us understand why some individuals don’t learn.