Hi,
Just to add that we really do discourage the merging of timeseries
data as it
messes up the pre-processing - especially the temporal filtering. You
are
much better adding a separate level where you average over the runs
using
the GLM, with the first level just doing each run separately. This
should be
fine if you have 5 runs per subject. Have a look at the documentation
at:
http://www.fmrib.ox.ac.uk/fsl/feat5/detail.html#MultiSessionMultiSubject
for more details.
All the best,
Mark
On 12 Nov 2008, at 20:19, Eugene Duff wrote:
> Hi Yael,
>
> It is a bit unclear what you need to do. If you just want to do an
> typical single-subject multi-session analysis you probably do not
> need to manually merge your data. You run an ordinary first-level
> analysis on each session, then run a higher-level analysis in Feat,
> where you include each of the 1st level Feat directories as inputs.
> Feat then automatically merges the appropriate 1st level datafiles
> before it does the modelling. Otherwise, fslmerge is the tool to
> merge data.
> Eugene
>
>
> 2008/11/12 Yael Shani <[log in to unmask]>
> Hi Reza
> I'm not sure I understand. When you say merge do you mean the in the
> second level analysis feat takes all the runs and concatenate them
> into one long run or averages the results of all the runs?
> Thanks again
> Yael
>
>
> On Sun, Nov 9, 2008 at 5:45 PM, Reza Salimi <[log in to unmask]>
> wrote:
> Hi Yael,
> to merge some volumes, you can use fslmerge which does it in
> different directions(x,y,z,t)
> and also, in case of using a typical feat analysis, this merging
> happens itself as a part of the group-level analysis and
> merged result is saved as filtered_func_data.nii.gz
> hope it helps.
> cheers
>
>
> On Sun, Nov 9, 2008 at 3:39 PM, Yael Shani <[log in to unmask]> wrote:
> Hi FSL'rs
>
> I want to do a within subject analysis, but before I need to
> understand how to merge data.
> Each subject had 5 runs. I would like to treat these runs as one
> long session. How do I do that? As far as I understand the second
> level analysis with fixed effects does not concatenate. Am I right?
> Many thanks
> Yael
>
>
>
> --
> G. Salimi-Khorshidi,
> D.Phil. Student, Dept. of Clinical Neurology, University of Oxford.
> [log in to unmask] http://www.fmrib.ox.ac.uk/~reza
> FMRIB Centre, John Radcliffe Hospital,
> Headington, Oxford, OX3 9DU
> Tel: +44 (0) 1865 222466 Fax: +44 (0)1865 222717
>
>
>
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