Dear Mehedi,
> I am a new researcher in the field of nuclear medicine in university of
> Tohoku, Japan. Now my research is based on analysis of positron emission
> tomography whole body data. I have some questions about SPM analysis
> which is given below__
> 1)Would you please clarify briefly about SPM(t),SPM(Z) and
> SPM(F).
Just to add to Stefan's full and helpful reply, two little points.
Firstly, SPM does not save the SPM(t), it only saves (and analyses) the
SPM(Z), which is derived from the SPM(t), by calculating the probability
of the t statistic at each voxel, then working out the Z score with that
p value, and replacing the t statistic with the Z value. It's a bit confusing
because SPM saves a matrix called SPMt.mat which is in fact an SPM(Z).
In a rough sense, it is worth thinking of the SPM(F) as telling you, at each
voxel, whether the effects of interest are in fact explaining anything in your
data (it represents the significance of the reduction in variance, at
each voxel, when adding the effects of no interest to a statistical model that
only included the effects of no interest). The SPM(t), and therefore the
SPM(Z), tells you the one-tailed significance of the t test that you have
specified with your contrast.
Hope that helps,
Matthew
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