Posted by Luiz Pessoa on April 06, 2001 at 20:11:27:
Hi,
When using 3dDeconvolve in a simple multiple regression analysis(that is, minlag = maxlag = 0; regressors previously convolved with some hemodynamic IRF) it is obviously important not to model all the data points (TRs). As explained on this board before, since AFNI automatically estimates a constant term collinearity would result if every point were included in some regressor.
I was wondering whether the same applies when using 3dDeconvolve to estimate the IRF. In this case, my question is whether one can model all of the event types at the same time. If my paradigm has 6 event types and I try to estimate the IRFs for all of the 6 at the same time, does this pose extra problems?
Thanks very much,
Luiz