I am looking to run 3dClustSim for my current resting-state fMRI analysis. Before running 3dClustSim, I want to estimate the smoothness of the noise in my data using 3dFWHMx, however I am not sure which input to use.
From what I’ve seen in task-based experiments, the ‘errts’ files are typically used as the input as this represents the noise smoothness. However, in resting-state analyses the ‘errts’ file (or output of @Anaticor) is the signal of interest, not the noise. In my processing pipeline, I performed filtering, censoring, and blurring in 3dTproject after running @Anaticor, so my resulting connectivity maps are smoothed using a 6mm kernel. I then performed a seed to whole-brain correlation analysis for each subject (in subject space) and plan to run 3dMVM on the MNI warped z-score files.
Based on my processing pipeline, should I use my MNI warped z-score maps as my input to estimate smoothness in 3dFWHMx or should I be using a file prior to the correlation analysis (i.e. all_runs [subject space] prior to @Anaticor)?