Fig. 4.

Hemispheric differences in the DTI properties of white matter tracts and cortical regions.

Asymmetry indices (Left-Right)/(Left + Right) of DTI parameters in the white matter tracts (a, n = 22) and in the cortical perisylvian regions (b, n = 21). a. Lower transverse diffusivity (${\text{λ}}_{┴}$) values in the left acoustic radiations (AR) and the left arcuate fasciculus (AF) compared to their right counterparts suggest a more mature microstructure in the left tracts. b. Similarly, the lower longitudinal diffusivity (${\text{λ}}_{\left|\right|}$) in the left than right angular gyrus (AG) and middle temporal gyrus (MTG) to a lesser extent, suggests more mature regions in the left hemisphere. The reverse pattern was observed for the inferior frontal (IFG) and superior temporal (STG) gyri, suggesting a more mature microstructure in the right hemisphere for these regions (statistical analyses are detailed in Table 2 ; asterisks represent significant differences from zero at p < 0.05, and dots a marginally significant trend at p < 0.1).