Fig. 3. Transformations between coordinate systems.

a, Registration fusion provides a framework for directly projecting group-level volumetric data onto a surface. Here, a probabilistic atlas for the central sulcus³⁵ has been projected independently onto the CIVET (41k), fsLR (32k) and fsaverage (164k) surfaces. b, MSM provides a framework for aligning spherical surface meshes. Here, we show sulcal depth information (originally defined in fsLR space) on spherical meshes that are aligned across the different coordinate systems, where each row represents a different coordinate system and each column represents the space to which that system is aligned. c, Example of a volumetric brain map (the first principal component of cognitive terms from NeuroSynth³⁴) that has been transformed to all surface-based coordinate systems using alignments derived from registration fusion. d, Example of a surface brain map (the first principal component of gene expression from the Allen Human Brain Atlas⁷) that has been transformed to all other surface-based coordinate systems using alignments derived from MSM. Note that because the original data are represented on the cortical surface, transformation to volumetric space is ill-defined and therefore not shown here.