Dear Friends:
I have a N-back study with 0-back, 1-back, 2-back, and 3-back 4 levels. I
used contrast [-2 -1 1 2] to assess the signal changes as task load
increased from 0-back to 3-back. I assume the voxels survived this test have
linear signal increase. But when I plot the signal changes, it showed little
bit signal decrease as task load increased from 2-back to 3-back. So some of
my colleges told me that I can't call it "linear signal increase". My
question is what is the proper term for this kind signal changes?
Thanks
Jiansong
|