Hi FreeSurfers,

These should be a simple questions but they have been bugging me.
  1. I have two diagnostic groups that I want to compare controlling for gender and age. I am entering them in Qdec with diagnosis and gender as discrete factors and age as continuous (n=89). If I use DODS I get non-sig result after FDR, but I am not sure if this is modelling back to age 0 – I have demeaned the age to try to get the mean age value but get the same results. I read that to overcome this you can use DOSS where I do get a significant results after FDR, but the results are exactly the same as the age-thickness correlation (I.e. There is no diagnostic effect, it is all age-related). Can you advise the best way to control for age and gender.
  2. Can you control for FDR over both hemispheres?
  3. After FDR, how can you adjust the heat bars so that you can approapriately compare between statical maps?
Thank you!