I basically want to look for out outliers. 

An additional question:

Would it make sense to calculate  the difference A.bvars -B.bvars  (where A and B  are combined mode parameter files for one group at time points A / B)   to account for the longitudinal design and test for the "null" hypothesis?

Luke

Am 07.05.2012 um 00:29 schrieb Mark Jenkinson:

Hi,

The output from the command will be a matrix of numbers (in text format) that is
the coordinate values by the number of subjects. d

All the best,
Mark

Dear Mark!

Thank you very much for the fast response.  So I have to reduce the analysis to pairwise comparisons, which also should work. However, what exactly will be saved using the mentionend option? Could one use the files for any kind of quality control?

All the best,

Luke

Am 05.05.2012 um 02:51 schrieb Mark Jenkinson <[log in to unmask]>:

Dear Luke,

I'm afraid we are still working on a longitudinal version of vertex analysis.

You can't implement a paired t-test with the current FIRST tools.

However, you could save out the vertex coordinates using the --saveVertices

option and then use other statistical packages to implement a multivariate

paired t-test.

Hope that helps.

All the best,

 Mark

On 5 May 2012, at 05:49, Luke wrote:

Dear FSL-Experts!

I wonder if FIRST can be used for longitudinal studies  ( in my case 2 groups (Placebo / Intervention) examined at two points  (T1/T2)). The analysis of the subcortical volumes via fslstats already revealed the expected result. Now I would like add a vertex analysis to infer shape changes due to the on the effect of the intervention.  Is there any issue of theoretical or practical kind that might argue against performing a vertex analysis in this situation? Any recommendations for the first_utils options in this situation?

Best wishes and many thanks in advance,

Luke

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