Dear SPMers,
I have attempted to implement a second level ANOVA (within subjects)
with 19 subjects and 5 conditions. I chose to do a sphericity
correction and identified the conditions as correlated measures.
The resulting SPM_F image for "all effects of interests" contain
negative values at all voxels, with zero being the highest value.
Negative F values should not be possible, should they?
I also specified a t-contrast with weights for the 5 conditions of -2
-1 0 1 2. The resulting t-map contains uniform values of zeros.
Any ideas about what may have gone wrong and how I can trouble-shoot
these peculiar results would be most appreciated.
Thanks.
Dan
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