Hello all,
I have a question about using the GLT option in 3dDeconvolve.
Say I have an experiment with three conditions:
a warm stimulus,
a hot stimulus (painful),
a hotter stimulus (even more painful).
One comparison I'm interested in making is the difference between painful stimuli and warm stimuli. In this case, two conditions are painful and only one condition is warm.
The first glt.mat file I have displayed below is set up considering that each condition has 3 lags, and that the baseline is modeled by a constant and a linear drift.
A) 0 0 -1 -1 -1 1 1 1 1 1 1
Most examples of the glt.mat I've come across have weighting factors that add to zero (instead of 3, as in A). With that consideration, I have a different permutation:
B) 0 0 -2 -2 -2 1 1 1 1 1 1
Which is the more valid comparison? Or is there a better option?
Eric
