Fig. 3.

Maturation of the linguistic pathways and perisylvian regions quantified with diffusion MRI.

a: Left panel: Example of tract reconstructions in a 12-week-old infant superposed on the map of DTI anisotropy: acoustic radiations (AR), auditory fibers of the corpus callosum (ACC) and arcuate fasciculus (AF). Right panel: Transverse diffusivity (${\text{λ}}_{\perp }$) plotted as a function of infants’ age in each tract (left and right values are averaged). Major age-related decreases are observed (n = 22).

b: Left panel: 3D parcellation atlas of a 10-week-old infant showing the studied regions: Heschl’s gyrus (HG), planum temporale (PT), superior and middle temporal gyri (STG, MTG), angular and inferior frontal gyri (AG, IFG). Right panel: Longitudinal diffusivity (${\text{λ}}_{\left|\right|}$) plotted as a function of infants’ age in each region (left and right values are averaged). Major age-related decreases are observed (n = 21).