I would like to model three different events (e.g., viewing of facial expressions, animals, and landscapes) and their parametric modulations (e.g., subjective pleasantness ratings given in each experimental trial). Then I would like to separate the effect of the subjective pleasantness modulation for one event from the effect of the subjective pleasantness modulation for the other event (i.e., see whether the type of modulation by the pleasantness rating is different for facial expressions and animals).

The problem is that I have troubles finding afni examples on the web. Would you use 3dDeconvolve for this kind of parametric modulation? I saw the topic amplitude modulation discussed in the forum, but this does not seem to apply to my case, where the focus is on the interaction of event and parametric modulation and not separate (main) effects of both.

Is there an example online I could refer to in order to write mysc-ript?

Would I be allowed to directly contrast modul_eventA - modul_event B? And if yes, how?

Thank you very much in advance for your help,
Jana