Ze - in theory this is a reasonable sequence, but one issue is that
voxels outside of the brain mask in the statsitics/contrast images
contain NaN, which cannot be interpolated so you will end up losing
some voxels around the outside of the brain after normalization. one
option is to dilate the brain mask so that you end up with extra voxels
outside the brain before normalization.
cheers
russ
On Jun 2, 2004, at 10:48 AM, Ze Wang wrote:
> Dear SPM authors,
> I have a simple question. What's the preprocessing order of spm?
> I'm now using: realignment, smoothing, GLM, coregisteration between
> the GLM results and the T1 anatomical images, normalization for group
> analysis. Another approach is to perform normalization before GLM and
> group analysis, is this affect the analysis results? What's the
> preprocessing order then? (Realignment, smoothing, coregistration,
> normalization, or Realignment, smoothing, 2 normalization (1 for
> anatomical images, the other for epi images), coregistration)
>
> Thanks a lot.
>
>
> Best regards.
>
> Ze Wang
> [log in to unmask]
> 2004-06-02
>
---
Russell A. Poldrack, Ph.d.
Assistant Professor
UCLA Department of Psychology
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