Hi Conny, this sounds like an interesting study.
Probably the first thing to check is just to run 4 simple group FEAT (ie
mixed effects) analyses for the 4 cases. Running them separately will let
you test that all looks sensible and give you a feel for how the different
acquisition strategies compare. Note, however, that higher mixed-effects Z
doesn't _necessarily_ mean better acquisition, but it often should do.
Then, if all is making sense, you can actually test for significant
differences between the strategies by using a complete group-level for all
data, as you say, with appropriate additional covariates for the different
strategies.
Thanks, Steve.
On Thu, 24 Apr 2003, Conny Schmidt wrote:
> Dear FSL community,
>
> I have a study of 14 subjects and 4 acquisition parameter sets tested.
> For each the same stimulation paradigm was used.
> What would be the best way in FSL/FEAT to check, which acquisition
> strategy turnes out to be the best?
>
> I think there should be some kind of "repeated measurements statistics"
> applied. Furthermore, is there a way to inlude then also additional
> covariates?
>
> Best regards,
> Conny
>
>
>
> --
> ------------------------------------------------------------------------
>
> Conny Schmidt
> Institute for Biomedical Engineering
> ETH and University Zurich Phone: +41-1-632 71 34
> Gloriastr. 35 Fax: +41-1-632 11 93
> CH-8092 Zurich, Switzerland Email: [log in to unmask]
>
>
> private:
> Oerlikonerstr. 5
> CH-8057 Zurich, Switzerland Phone: +41-1-363 13 39
>
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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