Yes, you just need to come up with the the contrast matrix taht tests what you want to test. If the contrast matrix has one row, then it's a t-test. If there are more than one, then it's an F test. You example is actually a t-test, I think, just:
(MaleTreatment-MaleControl) - (FemaleTreatment-FemaleControl)
for a contrast of: +1 -1 -1 +1
doug
Sasha Wolosin wrote:
Dear FreeSurfers,
I am interested in examining interaction effects between two sets of classes where each covers all the data, let's say Male/Female and Treatment/Control. I know mri_glmfit can be used to run t-test comparisons between groups (e.g. All Treatment vs. All Control , or Male & Control vs. Male & Treatment), but can mri_glmfit be used to examine interaction effects between these two sets of classes (for surface data)?
my FSGD file looks like this: GroupDescriptorFile 1 Class MaleTreatment Class MaleControl Class FemaleTreatment Class FemaleControl Input subjid1a MaleTreatment Input subjid1b FemaleTreatment Input subjid2a FemaleControl Input subjid2b MaleControl etc...
Thanks, Sasha
Sasha Wolosin Research Assistant Developmental Cognitive Neurology Kennedy Krieger Institute 707 N. Broadway Baltimore, MD 21205 ph: (443) 923-9270 wolosin@kennedykrieger.org
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