The averaged PC1 coefficients of different brain regions. The results come from dataset HM (A-C) and CF (D-F). The contribution was normalized by the sum over 4124 brain elements and averaged over the brain elements in the same region. The different brain regions include: brainstem (BS), corpus callosum (CC), cerebellum (CL), gray matter (GM), midbrain (MB), thalamus (TH) and white matter (WM).