We will try the "randomize" function but if I was to use the approach with 3dMVM -resid:
This gives me a _resid output file with 1800 values per voxel (we have 1800 subjects).
1) Should I loop through this sub-brik with 3dFWHMx, where the loop index is used to give 3dFWHMx one sub-brick at a time or can I just give it the full 4D-volume?
2) Should I use any of these option?
-demed = If the input dataset has more than one sub-brick
(e.g., has a time axis), then subtract the median
of each voxel's time series before processing FWHM.
This will tend to remove intrinsic spatial structure
and leave behind the noise.
[Default = don't do this]
-unif = If the input dataset has more than one sub-brick,
then normalize each voxel's time series to have
the same MAD before processing FWHM. Implies -demed.
[Default = don't do this]
-detrend [q]= Instead of demed (0th order detrending), detrend to
>>>>>
-geom }= If the input dataset has more than one sub-brick,
*OR* }= compute the final estimate as the geometric mean
>>>>>
-combine = combine the final measurements along each axis into
one result
3) Should I for structural data still use -ACF or is classical -fwhm sufficient?
I tried this:
3dFWHMx -input resid+tlrc. -ShowMeClassicFWHM
Got this:
++ start ACF calculations out to radius = 8.19 mm
+ ACF done (0.00 CPU s thus far)
2.73652 2.60893 2.85135 2.73047
0.773993 1.5801 7.99712 4.18496
++ ACF 1D file [radius ACF mixed_model gaussian_NEWmodel] written to 3dFWHMx.1D
++ 1dplot: AFNI version=AFNI_21.0.12 (Feb 25 2021) [64-bit]
++ Authored by: RWC et al.
+ and 1dplot-ed to file 3dFWHMx.1D.png
Are those values for all 1800 subjects?:
2.73652 2.60893 2.85135 2.73047
Edited 2 time(s). Last edit at 09/17/2021 07:21AM by Robin.
