Recruitment of an Area Involved in Eye Movements During Mental Arithmetic
André Knops,1,2,3,*
Bertrand Thirion,2,4
Edward M. Hubbard,1,2,3
Vincent Michel,2,3,4
Stanislas Dehaene1,2,3,5
Throughout the history of mathematics, concepts of number and
space have been tightly intertwined. We tested the hypothesis
that cortical circuits for spatial attention contribute to mental
arithmetic in humans. We trained a multivariate classifier algorithm
to infer the direction of an eye movement, left or right, from
the brain activation measured in the posterior parietal cortex.
Without further training, the classifier then generalized to
an arithmetic task. Its left versus right classification could
be used to sort out subtraction versus addition trials, whether
performed with symbols or with sets of dots. These findings
are consistent with the suggestion that mental arithmetic co-opts
parietal circuitry associated with spatial coding.
2 Commissariat à l’Energie Atomique (CEA), I2BM, NeuroSpin, F-91191 Gif-sur-Yvette, France.
3 Université Paris-Sud, F-91405 Orsay, France.
4 Institut National de Recherche en Informatique et en Automatique Saclay–Île de France, Orsay, France.
5 Collège de France, Paris, France.
* To whom correspondence should be addressed. E-mail: knops.andre{at}gmail.com
