Dear experts,
I have a question regarding the AlphaSim command for FWE correction of fMRI data.
Is there any substantial difference between using AlphaSim and 3dClustSim, apart from the option of having cluster size for multiple p-values in the latter command?


Hi Giovanni,

While they do basically the same thing, 3dClustSim
gives much more output, including outputs for
multiple neighborhood types.

Importantly, 3dClustSim also includes the -acf option,
to apply more accurate auto-correlation function
estimates. I see little gain in using AlphaSim, except
that it gives more detailed output to understand
exactly what the corrected p-value is.

  • rick