> want to know if the output option "-Mean" write the average Fisher's Z scores to the output dataset.
The output is just the average correlation across the brain.
> If not, how can I get the FZ scores?
Use option -Zmean, 3dTcorrMap can 1) compute the voxel-wise correlation and convert it to Z-score, 2) perform the averaging across the brain, and 3) convert back to correlation. If you really want the output in Fisher-transformed Z-score, you can convert the output back to Z-score:
3dcalc -a yourdata_R -expr 'atanh(a)' -prefix yourdata_Z
Gang
