Name: Brian Butterworth
About you: I was Professor of Cognitive Neuropsychology at University College London from 1992 until last year, when I became Emeritus (unpaid). Most of my work at the moment is on a congenital condition called developmental dyscalculia, which is an inability to learn arithmetic. It’s rather like dyslexia, but for numbers.
How I got to be doing this, is rather a long story. I started postgraduate work on formal languages and the foundations of mathematics, but moved into research on natural language, very natural language – hesitations in speech. There was a natural progression into disorders of speech and language following brain damage called ‘aphasia’. Once you start going to neuropsychology clinics to study the cognitive effects of brain injury, you meet fascinating patients. Some of them seemed to have problems just in mathematics (acalculia), and I began to become more interested in these patients, and discovered that there is a brain network specialised for processing numbers, and if this is damaged then maths is impaired. I thought this might be a way to take an empirical approach to the foundations of mathematics.
What was a surprise was that some of these patients had very specific disabilities. Some were unable to count beyond four, others could do addition but not multiplication, others multiplication but not addition; some had superb calculation skills even though their language had almost completely disappeared. It turned out that the brain not only had a network for numerical processing, but sub-networks for distinct arithmetical tasks.
A natural next step was to find out why and how the brain becomes specialised in this way, and this meant looking at how children learned arithmetic – and in particular, at what kinds of specialised cognitive and neural capacities the child brings to learning arithmetic. This has led to the striking finding that a child can be born with a selective inability to learn arithmetic – not all maths, just numerical aspects of it – these are the dyscalculics. Recently, we have found inherited brain abnormalities in dyscalculic learners, and we have started to go gene hunting, beginning with genetic abnormalities that seem to target maths more than any other cognitive capacity.
Along the way, I have written a popular book about everything I’d learned about the origins of our numerical abilities, The Mathematical Brain; and I launched a journal for people like me, Mathematical Cognition, which the publishers, Psychology Press, closed down after five years without consulting me, and just as the whole area began to explode, just as we predicted.
One of my jobs now is to persuade government, teachers, parents, and learners, that being unable to learn arithmetic isn’t necessarily a sign of stupidity, but it’s rather the numerical equivalent of dyslexia and that specialized help is needed for these learners, just as it is for dyslexia. One of the outcomes of this work has been the creation of an inter-institutional Centre for Educational Neuroscience, that brings together neuroscientists, psychologists and educators from UCL, Birkbeck and the Institute of Education, to explore other areas where these disciplines can get together to make the learner’s life better and happier.
The most recent use of mathematics in your job was...
Endless statistics to analyse experimental results.
Some mathematics that amazed you is...
I am amazed that non-human species can do mathematics. Chimps are better at remembering number sequences than we are. Newborn chicks can add and subtract. Even fish have a sense of number.
Mathematics is one of the things that makes human beings what they are. We have inherited a capacity to do wonderful things with numbers. Stone-age cavemen (they didn’t really live in caves except when the weather was awful) counted the waxing and waning of the moon. We have discovered that tribes whose languages contain no counting words, and whose culture contains no counting practices (for example, in Australia), nevertheless have the same numerical capacities as members of numerate societies.
A significant mathematics-related incident in your life was...
Going through the proof of Gödel’s theorems and finding out that my hero, Bertrand Russell, was wrong about the foundations of arithmetic.
A mathematics joke that makes you laugh is...
A mathematician is a machine for turning coffee into theorems (attributed to Erdős).
The best book you have ever read is...
I really loved G H Hardy’s A Mathematician’s Apology, and the Foreword by C P Snow.
Who inspired you?
Bertrand Russell, whom I never met, alas. Of those who I have met, Tim Shallice and Elizabeth Warrington got me interested in neuropsychology, and showed me that it was possible to test theories of normal cognition by studying extremely abnormal individuals.
If you weren’t doing this job you would…
Be an archaeologist. It’s not too late!