Dear experts,

When using CONN to preprocess the fMRI data, I have a question about the default Direct segmentation and normalization step. 

This step contains two functions: functional_segment&normalize_direct, structural_segment&normalize. My question is: since we have normalized the functional data to MNI space and segmented it (which means that we have brain masks and MNI-space parcellation can also be used), why do we need to do the same thing with the structural data? What is the role and function of structural_segment&normalize? 

Thank you for your consideration, and I am looking forward to your reply.

Yi