Hi Volkmar,
Thanks for the comments.
-The first cell consisted twenty-five, the second cell (21) and the third cell (20) smoothed images corresponding to three groups. In total, sixty-six smoothed grey matter (timepoint 1 - timepoint 2) were incorporated in the one-way ANOVA between group analysis (a figure of design matrix attached).
-By default, implicit masking was applied.
-Global normalization: proportional scaling
Alternatively, I used a flexible factorial design to test the effects of group by time interaction using a F-contrast in CAT12 (design and contrast matrix attached). No voxels survived after the multiple comparison correction. In the other contrast of interests, some brain regions showed GMV changes for the main effects of group as well as the main effects of time. Now, I would like to clarify whether the design matrix and the contrast matrix (especially for the group by time interaction) is correct for this specific analysis.
I would be grateful for your feedback!
thanks, and regards
Varun
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