Fig. 2: Cortical microstructure diverges along the sensorimotor-association axis and reflects cytoarchitectural classes & laminar differentiation.

A The first and B second structural gradients (SG1 & SG2) derived from the dMRI measures (red and blue indicate opposing ends) along with myelin and cortical thickness. C The Sensorimotor-Association (SA) axis (blue indicates sensory regions, red indicates association areas) and D the correlation between SG2 and SA axis is statistically significant under spin permutation testing (r = 0.687, p = 0.004). The top tertile (60 regions with the highest rank) and bottom tertile (60 regions with the lowest rank) are taken to be the association tertile and sensorimotor tertile respectively. E Both SG1 (t = 4.4, p = 2.9e−05) and SG2 (t = 11.4, p = 2e−20) had statistically significant divergence between sensorimotor and association regions. F Cortical metrics significantly diverged between association and sensorimotor regions: QIV (t = 10.2, p = 5.4e−18), DKI-RD (t = 8.0, p = 5.1e−12), DKI-MD (t = 7.9, p = 5.1e−12), DKI-AD (t = 7.5, p = 3.2e−11), THICK (t = 7.3, p = 1.3e-10), MSD (t = 9.1, p = 1.7e−14), KFA (t = −2.7, p = 0.01), ODI (t = 4.3, p = 5.8e−05), RTOP (t = −4.8, p = 7.9e−06), RTAP (t = −5.5, p = 3.5e−07), ICVF (t = 5.8, p = 9.8e−08), RTPP (t = −6.3, p = 1.1e−08), MYL (t = 10.5, p = 2.8e−17). Sensorimotor regions are shown in blue and association regions are shown in red. G SG1 (F = 19.4, p = 2.0e−14) and SG2 (F = 26.5, p = 6.2e−19) were stratified by the Von Economo cell types. H SG1 (F = 21.9, p = 4.7e−13), SG2 (F = 27.6, p = 9.3e−16) were also stratified by the Mesulam’s hierarchy of laminar differentiation.