Figure 1.

Superficial anatomy of the inferior parietal lobule (IPL). (a) The supramarginal gyrus (SMG) loops around the postero‐superior extension of the lateral sulcus (i.e., the Sylvian fissure). The angular gyrus (AG) similarly wraps around at the parietal extension of the STS. (b) Fiber dissection revealing the superficial connections of the SMG and AG. These tracts primarily facilitate local and intragyral connectivity, taking an oblique angle from the cortical surface. Some fibers from the SMG and AG travel superiorly to the superior parietal lobule (SPL). (c, d) Tractography demonstrating the orientation of superficial fibers from the IPL. Lateral (c) and supero‐lateral (d) views illustrate the fronto‐occipital and temporo‐occipital orientations of fibers connecting to the SMG, and the temporo‐occipital orientation of fibers connecting to the AG. Pink: SMG, fibers connecting to the SMG; Blue: AG, fibers connecting to the AG; IPS, intraparietal sulcus; LS, lateral sulcus (or Sylvian fissure); PN, preoccipital notch; STS, superior temporal sulcus