I never received a response to this question and I'm still really confused about how to interpret the results. When I use a single hpow value in ETAC (0,1, or 2) for some contrasts, I do not get any significant clusters. However, when I use a combination of hpow values as in the command below, I do get significant voxels.
-ETAC_opt NN=2:sid=2:hpow=0,2:pthr=0.01/0.001/19:name=h1:fpr=5 -ETAC_opt NN=2:sid=2:hpow=2:pthr=0.01/0.001/19:name=h2:fpr=5
I've read the Etac paper and I can't wrap my head around why adding more comparisons (additional hpow values) would make some voxels pass the test when there were none that passed the test with a single hpow. I would greatly appreciate any help!