Yes, the 3dClustSim results were done without including the blur option.

Which leads me to another question regarding the -acf option in 3dClustSim:

The values you get from the -acf option are from 3dFWHMx, correct?

However, my preprocessing was done in SPM on resting state data, and then we ran a group ICA analysis on the preprocessed datasets. There is no errts file I could find in the output results.

Based on the 3dFWHMx -help:

INPUT FILE RECOMMENDATIONS:

* If you don't want to go to that much trouble, use '-detrend' to approximately
subtract out the anatomical spatial structure, OR use the output of 3dDetrend
for the same purpose.
* If you do not use '-detrend', the program attempts to find non-zero spatial
structure in the input, and will print a warning message if it is detected.

Should I use the detrend option if my input datasets are just preprocessed timeseries, resting-state data?

One more thing: if the ACF is derived from each subject, how do we include these values for group analysis? If we use a group_mask for the mask option in 3dClustSim, what values for the acf option do we use if we have 20 subject acf values from 3dFWHMx?

Thanks.

Michael