Hello,
recently I decided to rerun group analysis on some old data. The reason
was that the original group analysis was done using the old version of
Feat, and I wanted to see the additional reports from the new version
of Feat (the Summary of low-level registration and masks). So I loaded
the design.fsf into Feat, changed the output directory, verified that
everything is OK, saved and run. But the (statistical) results are
different. No only in the report, but I also subtracted zstats images -
and there are big differences. I inspected the design.fsf files, and
the only difference I could find (apart from the obvious differences in
the layout for new and the old versions) is that in the new design.fsf
file, the degrees of freedom to standard image was set to 7, whereas in
the old one it was 12. But that should not cause any problems because
the registrations were already calculated in the single subject
analyses, and the first step of the group analysis just applies those
transformations - right?
Also, I notices that the background image for the two analysis looks
quite different - even though in both design files it was set to the
"mean highres". I looked at the log files and the commands executed to
create those seem to be the same.
Am I missing something? The statistical results should not be
different? Is there anything else I should be checking? by the way, the
single subject analyses were not changed after running the initial
group anlaysis...
thanks
zrinka
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