Hello all,
I had a question regarding group analysis (paired t-test),
There is a group of 5 subjects, scanned under two different conditions. Let say, an Easy and a Hard.
I performed a group feat paired t-test to compare the two conditions. So, there were 5 input feat directories (5 subjects) for each condition, total of 10 inputs. The contrast defied earlier in the first level feat analysis for individual runs and later for the group run are as follows,
Individual Group
a
b Easy- Hrad
a-b Hard- Easy
b-a
After running the group feat, in the results, I found the spatial activation maps for,
a-b > Easy-Hard to be exactly same as the b-a > Hard-Easy.My question is why is there this redundancy and are these results reliable?
Thank you!