Hello again,
So regarding the first question: the number of trials for one condition is indeed (in fact exactly) three times more than the other condition (9 vs. 27). I've heard FSL can handle this correctly - is there a way for AFNI to handle this?
Regarding the second: you've got it right. I think ASL would be a between subjects variable. Basically, the idea is to correct for changes in blood flow from pre to post medication administration. Group = whether or not they got placebo or active treatment. So I'm thinking that ASL-scan 1 minus ASL-scan 2 could be a between subjects variable.
Thanks again Gang!
Claire
