The foundations of numerical thinking in a brain without numbers

Dehaene et al. have presented data that provide strong new evidence for the dichotomy between perceptually and conceptually based quantitative competence, and pose new questions about which common cultural experiences are necessary to stimulate the authors' brains to organize themselves in such a way as to add these, initially unspecified, functional capabilities.

Abstract

In a recent paper, Dehaene et al.1 Dehaene S. et al. Sources of mathematical thinking: behavioral and brain-imaging evidence. Science. 1999; 284: 970-974 Crossref PubMed Scopus (1260) Google Scholar investigated the cognitive and neural bases of mathematical thinking, the key findings of which were summarized by Butterworth as indicating that ‘mathematical ability… results from the integration of two non-numerical neural circuits in the brain’ 2 Butterworth B. A head for figures. Science. 1999; 284: 928-929 Crossref PubMed Scopus (72) Google Scholar . One of these non-numerical circuits is in the left frontal lobe, which is associated with linguistic representations, in this case, representations of exact numerical values. The other is found bilaterally in the parietal lobes, a part of the brain associated with visuospatial functions in general, and, by Dehaene et al. in particular, with representations of approximate quantities in the form of a number line 3 Dehaene S. The Number Sense. Oxford University Press, 1997 Google Scholar .