Intrathalamic and extrathalamic paths of the tracts connecting MD with four cortical areas belonging to the same IFC group region. A, Streamline visualizations of the tractographies between MD (red line contour) and area 45 (yellow), area 47l (green), area IFSa (blue), and area IFSp (purple). The part of the cortex corresponding to each seed area is delineated, and its pial surface is highlighted in color. Each tract is coded in the corresponding color; white indicates coregistration of all four streamlines in the same voxel (indicated by an arrow). Note that the tracts coregistered extensively (arrow) from their origin in MD and in the internal capsule, all the way into the subcortical white matter where they split, with the tract directed to area 47L showing less overlap with the others. The asterisk indicates the coronal slice from which the magnified image shown in B was taken. B, Magnified visualization of a coronal slice showing the streamlines radiating into the middle layers of cortical area 45. C–F, Coronal sections of both thalami at higher magnification. Tractographies were obtained from the same individual shown in Figure 2. Scale bars: A, 1 cm; E (for C–F), 1 cm. Conventions and abbreviations are as in Figure 3.