THE LANGUAGES OF THE BRAIN

How did language and mathematics emerge in humans during the course of evolution? Scientists since Galileo have insisted that mathematics is structured as a language – but is this language similar to spoken language? Do mathematicians use classical language areas when doing mathematics? In the first part of the talk, I will present converging evidence that the left posterior superior temporal sulcus (pSTS) and inferior frontal gyrus (IFG, pars triangularis and orbitalis) play a central role in the syntax of spoken and written natural languages. In the second part, I will present fMRI studies investigating whether these brain areas also contribute to various aspects of mathematics. When professional mathematicians reflect upon high-level mathematical concepts in algebra, analysis, geometry or topology, the activation spares classical language areas. Instead, high-level mathematics involves bilateral intraparietal areas involved in elementary number sense and simple arithmetic, and bilateral infero-temporal areas involved in processing Arabic numerals. The evidence suggests that the acquisition of mathematical concepts recycles areas involved in elementary number processing. My conclusion will be that human brains are attuned to many different languages – spoken, written, mathematical, musical... – and that brain evolution may have endowed the human brain with a widespread ability to manipulate nested syntactic structures in most, if not all domains of human cognition.