Once we obtained the white matter and pial surfaces, the laminar profiles were delineated within the cortical gray matter. They were constructed at fixed relative distance between the white matter and pial surfaces, determined from cortical thickness [21]. The position of each vertex on intermediate surfaces depends on the position of the correponding vertex on the white matter surface (Fig. 1). The first intermediate surface was located at 16% of cortical thickness away from the white matter surface, then at 32%, 48%, 64%, 80%, and 96% depths, giving us a total of 6 layers (Fig. 1). In addition, cortical regions defined on the inflated surface were automatically obtained from the Desikan–Killiany (DK) Atlas, including the primary somatosensory cortex [9]. The whole thalamus was identified in MRI volume data using automatic subcortical segmentation proposed by Fischl et al. [83]. We defined the sensory core thalamus (VPL) mask from the Oxford thalamic connectivity atlas [84] in common MNI space, and transformed the mask to each individual’s coordinate space.
