fALFF: normalized vs. raw data differences

Dear Conn Experts,

I have used Conn to calculate the fALFF differences between two groups. However, when I use the normalized (Z score transformed) fALFF values, the results are much more sparse than the fALFF case. Is this behavior expected? More generally, why are we using Z score transformation (for making the data more normal)? Are there other methods that one could use?



Thanks!