Figure 1.

Examples of different types of sulcal patterns. (A) Presence of the fold. The sulcal pattern of the anterior cingulate cortex (ACC) can be “single”, with only the cingulate sulcus, or “double parallel”, with an additional paracingulate sulcus (PCS). Adapted from Cachia et al. (2014). (B) Interruption of the fold. The sulcal pattern of the inferior frontal cortex (IFC) can be continuous or with an interruption (red arrow). The sulcal pattern of the lateral occipito-temporal sulcus (OTS) can be continuous or have an anterior or a posterior sulcal interruption. Adapted from Cachia et al. (2014); Borst et al. (2016); Cachia et al. (2018), and Tissier et al. (2018). (C) Spatial organization. The sulcal pattern of the temporo-parietal junction (TPJ) is characterized by the spatial organization of the posterior part of the right Sylvian fissure (pSF) including Sylvian fissure (in blue), post-central sulcus (green) and central sulcus (in red). Type I, has both a vertical branch (planum parietale) that ascends into the supramarginal gyrus and a horizontal branch (planum temporale) that forms the superior surface of the superior temporal gyrus. In Type II, the Sylvian fissure lacks a vertical branch. In Type III, the horizontal branch extends posteriorly to the supramarginal gyrus into the angular gyrus. In Type IV, the vertical branch connects the post-central sulcus anterior to the supramarginal gyrus, the horizontal branch is therefore absent. Adapted from Steinmetz et al. (1990) and Plaze et al. (2015).