I read the “Simple Correlation Analysis” introduction from AFNI here: https://afni.nimh.nih.gov/SimAna. My question is if it is save to use my already preprocessed resting-state as well as task-based runs to do FC calculations via AFNI on these runs. If I do that, would it be correct to skip step 1) and 2) from the link above, since the raw runs are already preprocessed (bandpassed, nuisance regressed, etc.)? Can I directly start with my ROIs and all the rest (step 3) on)?
Or would this lead to wrong/faulty results for FC? Am I missing something else?