Hi
It seems that what you want to do is to run a second-level fixed-
effects analysis for those subjects that do have more than one run.
You might want to combine these into a single 2nd level analysis
(see the "Group difference with multiple sessions for each subject"
example in the FSL course practical ( http://www.fmrib.ox.ac.uk/fslcourse/lectures/practicals/feat3/index.htm
). For the 3rd level analysis set the analysis type to "Higher-level
analysis" and then "Inputs are 3Dcope images from FEAT directories".
Subjects with multiple runs then have their 2nd level cope images
entered whereas for subjects with a single run use the 1st level copes.
hth
Christian
On 7 Jul 2008, at 18:57, Marcus Schmidt wrote:
> I am working on analysis of a dataset using FEAT where I seem to
> have hit a
> bump in the road. The study design is of three runs for each
> subject, where
> only order of probe changes between runs. My problem is that two
> subjects
> (both from the same group; two total groups in study, each with
> n=24) had
> significant motion in their two later runs, leaving each with one
> available
> run for analysis. I have tried to run within subject higher level
> analysis
> for both of these subjects in FEAT, but for obvious reasons FEAT
> higher
> level analysis requires at least two runs to proceed (which as
> stated is not
> possible).
>
> I am wondering how one might perform between subject higher level
> analysis
> when some subjects have only one run, but others have multiple runs.
>
> Any thoughts, help, advice are greatly appreciated.
>
> Cheers,
> Marcus Schmidt
>
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