Hi Andy,
I think what you did is correct - ie the group mean over all 8 subjects of
each subject's 3rd first-level contrast. It seems that you have no
activation at the levels chosen - try looking at the unthresholded stats
image (in the stats subdirectory) to find out if anything nearly reached
threshold.
Thanks, Steve.
On Tue, 17 Jun 2003, Andy Myers wrote:
> On Tue, 17 Jun 2003 17:06:41 +0100, Christian F. Beckmann
> <[log in to unmask]> wrote:
>
> >Hi
> >
> >yes, it's copes and varcopes that are being passed up to a higher
> >level. Higher level results will be computed for all lower level copes.
> >
> >ta
> >christian
> >
> >
> >On Tuesday, Jun 17, 2003, at 14:18 Europe/London, Andy Myers wrote:
> >
> >> do u use the cope images in 2nd and further analysis to look at group
> >> mean
> >> effects for a particular contrast, and would you just use, for example
> >> the
> >> cope3 image in the /stats folder in your feat directory for each
> >> subj/session/etc.?
> >>
> >> andy
>
> ok, i used the cope3 (ie-the 3rd contrast that i did) on each of the 8
> subjects and passed them in to higher level therefore they appeared as 8
> inputs then had one ev that i set to 1 and one contrast that i set to 1 ie-
> a group mean, but after it had done i looked at the results and there was
> a nice pretty picture of the brain in slices but no activations on it????
>
> have i done something wrong or is my data THAT bad:)
>
> andy
>
Stephen M. Smith MA DPhil CEng MIEE
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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