afni.nimh.nih.gov

> If I wanted to compare that, however, to a standard double gamma HRF would it be appropriate to
> use SPMG2 or GAM?

Sure. You may also try out SPMG3.

> Or alternatively, would something like dmBLOCK be better?

dmBLOCK is usually used in cases where the stimulus duration varies across trials.

Gang