Newborns not only recognize their mother tongue at birth but are also capable of distinguishing far better than their mothers the totality of sounds of languages spoken on earth. What is the particular organization of the human brain that permits such linguistic abilities? During my Ph.D., I studied language areas in the brain's anatomy to better understand the early acquisition of language in life. Anatomy was described and analyzed by using magnetic resonance images (MRI) on infant brains. Several methodological tools have been built: First, a cortical segmentation framework to deal with the weak image contrast during the first months of life; Second, a maturation index based on the cortical image intensity. As it was expected, the index strongly increased with age in every region of interest. Then, we manually drew cortical sulci within language areas and measured asymmetry and maturation indices along these sulci. Early organization was found in language areas close to the one reported in adults for both indices. First, we reported: a little-known depth asymmetry of the superior temporal sulcus; An early forward and upward shift of the posterior end of the right Sylvian fissure; Asymmetrical sizes of both the planum temporale and the Heschl's gyrus. Second, the maturation index value of the Broca's area was unexpectedly high. Furthermore, maturation indices of both Broca's area and the posterior part of the superior temporal sulcus were correlated with another developmental index in the arcuate fasciculus. This correlation suggests the early development of the linguistic dorsal pathway between Broca's area and temporo-parietal regions.
