Hi Yun,
It is generally problematic to remove timepoints from timeseries data. See
Tim's recent email to the list on this, and also the FA at
http://www.fmrib.ox.ac.uk/fslfaq/#feat_dummy for more details.
Hope this helps?
Thanks, Steve.
On Wed, 5 Jan 2005, Yun Dong wrote:
> Dear FSL experts,
>
> We have been using FSL to analyze individual stroke patient's data
> acquired at different time points (pre-therapy, in the middle of
> therapy and post-therapy).
> As you can imagine, some patients can not hold still for the entire 5
> min run while performing a motor task especially when he/she uses the
> affected hand.
> Therefore, it is necessary to delete some problematic volumes related
> to motion and associated movement before analyzing the data from one
> run.
> Since our purpose is to longitudinally compare the activation pattern
> from the same subject to detect possible changes in activation, I have
> an intuitive feeling that we
> should keep the remaining volumes (after deletion of the volumes
> related to motion) as close as possible
> among the scans acquired at different time points. Statistically, is
> it necessary to do so?
>
> I appreciate it any thoughts and suggestions from you.
>
>
>
> Yun
>
>
> Yun Dong, MD, PhD,
> Postdoc Research Associate
> Laboratory of Motor Behavior and Neurorehabilitation
> Dept. of Biokinesiology and Physical Therapy
> 1540 E. Alcazar St., CHP-155
> Los Angeles, CA 90089-9006
> Office Phone: 323-442-1006
> Lab Phone: 323-442-1196
> Fax: 323-442-1515
>
--
Stephen M. Smith DPhil
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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