In general, source-level data can be parcellated with ft_sourceparcellate, but only if your atlas is in the same space as your functional data. That is, there should be a one-to-one mapping between the source locations in your functional data, and

source construction issues

For EEG, always prefer the “OpenMEEG BEM” model. for forward problems  Link The mnemonic ‘spm’ for the coordsys is used to indicate this MNI-based convention. Ft_volumerealign does not change the anatomical data, instead it creates a transformation matrix that aligns