Dear FreeSurfers,

I have been doing some basic cortical thickness analyses, which all went good. Now I want to analyze some additional things, and I want to make sure that my contrast files are ok. Could you help me out or give me advice?

So, I have three groups (control - MCI - Alzheimer) and I want to examine the effect of blood pressure on each group separately (corrected for age centered). Thus, I would make three different fsgd files with this contrast: 0_1_0

Then I want to compare how blood pressure effects the group differences (controls vs MCI / MCI vs AD/ controls vs AD) when controlling for age: would that be: 0.5 -0.5 -0.5 0.5 0 0 ?

Every help is greatly appreciated1

Thank you Best Heidi

================================================ Dr. Heidi Jacobs Postdoc researcher Faculty of Health, Medicine and Life Sciences School for Mental Health and Neurosciences Division Cognitive Neuropsychiatry and Clinical Neurosciences Alzheimer Center Limburg h.jacobs@maastrichtuniversity.nl www.maastrichtuniversity.nl www.heidijacobs.nl

Dr. Tanslaan 12, 6229 ET Maastricht P.O. Box 616, 6200 MD Maastricht, The Netherlands T +31 43 38 84 090 F +31 43 38 84 092 ================================================