Hi
I used the Realign and reslice process in spm 8 to correct for movement from a set of fmri files (.nii; 300 frames)
I used the option .Num Passes "register to mean" and after the processing i got the estimates for translation and rotation parameters , for the 300 frames.
Why these parameters start at 0 for frame 1 ?? .
if we have used the option Num Passes ''register to first'', then it will make sense but not here because the reference volume is the mean fmri volume and not the first frame.
I suppose because it is a two pass procedure that spm give you the parameters from the first pass procedure ( realignement to first slice) but where can we find parameters estimated from the second pass procedure ( realignment to mean) , because i suppose that in this case you cannot use these inaccurate parameters into the GLM ?
Best regards
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