Thanks so much for the clarification. I had one follow-up about some weirdness I am seeing within the global output.

I tried it first with two hpowers based on something I had seen in an example:

-ETAC 8 -ETAC_blur 0 2 -ETAC_opt NN=1:sid=2:hpow=0,2:pthr=0.05,0.01:name=Fred1
This resulted in a fair amount of activity surviving the mask.
But then I saw the comments in the etac help which suggested running hpow=0 for ease of explaining and hpow=2 if you expect small clusters (one main area of interest is small, so I thought this might be good). I ran them both separately.

-ETAC 8 -ETAC_blur 0 2 -ETAC_opt NN=1:sid=2:hpow=0:pthr=0.05,0.01:name=Fred1
nothing survived

-ETAC 8 -ETAC_blur 0 2 -ETAC_opt NN=1:sid=2:hpow=2:pthr=0.05,0.01:name=Fred1
nothing survived

For 'fun' I tried a few more:

-ETAC 8 -ETAC_blur 0 2 -ETAC_opt NN=1:sid=2:hpow=1:pthr=0.05,0.01:name=Fred1
nothing survived

-ETAC 8 -ETAC_blur 0 2 -ETAC_opt NN=1:sid=2:hpow=0,1,2:pthr=0.05,0.01:name=Fred1
mostly overlapping with the initial run using hpow=0,2

So this leaves me pretty confused. I obviously want to do things correctly, and I would love for something to survive!! Any Idea why there is a difference if you run them separate versus combined? And there is no way to see the individual contributions from the hpow settings when you use more than one in an etac command?

For reference, this is a paired t-test on 16 subjects using AFNI 18.3.05.

Thank you!
Stephanie McMains