Hi,
I really think this depends on if you think that atrophy increases
during time points 1 and 2. If you expect brains to stay basically the
same, I'd include only 1 T1 measurement per subject. If you expect a
*change* of atrophy over time (i.e. more atrophy at timepoint 2 than
at timepoint 1) to be an additional confound, you should use the whole
sample for template generation and use the T1s of the respective
timepoints in your design matrix.
Hope that helps,
Cornelius
On Thu, Aug 30, 2012 at 3:03 PM, Lies Clerx
<[log in to unmask]> wrote:
> Anyone?
>
> Your help is really appreciated!
>
> BW,
>
> Lies
>
>
> On Aug 29, 2012, at 1:17 PM, Lies Clerx wrote:
>
> Dear all,
>
> I am setting up a dual-regression with 1 group of subjects which has resting
> state scans at different time-points which I would like to compare (so
> pairwise comparison of 10 subjects with each 2 time-points).
>
> When creating the GM_template (by means of feat_gm_prepare) which will be
> used later on as an extra (voxel-wise) EV in my design (randomise step DR) I
> was wondering if I have to add all resting state scans from all time-points
> to create the template or only the first time-points since the same subjects
> are involved?
>
> So, my question is: do I need to add 20 *.nii.gz-files into my template
> (Subject 1 timepoint 1 - subject 2 timepoint 1 - .... - subject 10 timepoint
> 2) or only the first timepoint of each subject (10 *.nii.gz-files)?
>
> I hope that my question is a bit clear...
>
> Thank you in advance!
>
> BW,
>
> Lies
>
>
> Lies Clerx, Msc. | PhD student | Clinical Psychologist | Alzheimer Center
> Limburg | Department of Psychiatry & Neuropsychology | School for Mental
> Health and Neuroscience | Maastricht University
> Visiting address: Dr. Tanslaan 12, 6229 ET Maastricht, the Netherlands (room
> 4.E3.002) | Postal address: P.O. Box 616, 6200 MD Maastricht, the
> Netherlands
> T +31 (0)43 38 81841 | [log in to unmask]
> |www.maastrichtuniversity.nl | www.alzheimercentrumlimburg.nl
>
> Steun het Alzheimer Centrum Limburg in de strijd tegen Alzheimer. Kijk op
> www.geefomalzheimer.nl
>
--
Cornelius Werner
cornelius.werner<at>gmail.com
|