Use the significant clusters as ROIs doug

On 09/07/2012 10:43 AM, Meng Li wrote:

Hi professor, Thanks for your letter. When I perform the analysis of interaction by using the matrix： 0.25 0.25 -0.25 -0.25 -0.25 -0.25 0.25 0.25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 I get the significant clusters which have interaction. Then I do post hoc analysis, that is, I want to analyze the effect of two genotype on the A group (or B group), should I use the significant clusters as ROIs, or analyze on the whole brain directly?

At 2012-09-07 22:12:25,"Douglas N Greve"greve@nmr.mgh.harvard.edu wrote:

...

That is the correct matrix to use. You can create a new FSGD file (and the second matrix would be correct for it), but you do not have to. It will save you a few degrees of freedom. doug

On 09/07/2012 05:49 AM, Meng Li wrote:

...

Hi professor, Thanks for your reply. When I perform the main effect of dignosis, is the following matrix I used correct? 0.25 0.25 0.25 0.25 -0.25 -0.25 -0.25 -0.25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (I think it regressed out the effect of genotype and gender, that is it takes the genotype as a covariable)

Or I should create another fsgd file, that has 4 classes: AF, AM, BF, BM. And I can use the matrix (0.5 0.5 -0.5 -0.5 0 0 0 0 0 0 0 0) to perform the main effect of diagnosis. Which one of two mentioned matrix is right? Thanks a lot. Best wishes Meng

-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422

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