Hello AFNI experts,

Sorry first I am so novice in AFNI and fmri studies...

My experiment uses binocular rivalry.
As you might know, perception during binocular rivalry is not fixed. Dominance duration of one stimulus over another varies every time.

There are four conditions and I am trying to find out whether there's any difference in fmri signal between conditions during that stimuli's dominance phase. So my event onset text file contains the onsets of "dominance response" for each condition.

My questions are,

1. I'm wondering which HDR model I should use.(dmBLOCK vs GAM)
Since the event durations vary, is it reasonable to use dmBLOCK(0) for 3dDeconvolve?


2. What exactly is the reason of using dmBLOCK? Does it give less weight for shorter durations and bigger weight for longer duration? Or does it reduces(?) the gap between different durations? What is the exact meaning of "Modulating durations"?


3. When do you use dmBLOCK(0) and dmBLOCK(1)? What's the difference of two? Does longer duration in dmBLOCK(0) implies bigger amplitude of BOLD signal whereas all durations' peaks are 1 in dmBLOCK(1)??



Thank you very much in advance.



Edited 1 time(s). Last edit at 02/18/2020 03:21AM by Seungmin.