Hi All,
I have two conditions of interest in my GLM analysis, Condition A and
Condition B. I would like to make a contrast of Condition A and Condition B
that includes only those vertices that are significantly positively
activated when compared to the Passive Viewing baseline. In other words, I
would like to mask anything that is Passive > Condition A or Passive >
Condition B and only include Condition A > Passive and Condition B >
Passive when contrasting Condition A and Condition B, so as to limit my
contrast to changes in *activation *in the two conditions, not *deactivation
*.
I see that in an older version, when isxavg-re-sess was used, there was a
flag --trunc that would allow you to set the negative values to 0. If there
is a way to do this in the v 5.1.0, I could then perform a second level
contrast of positively activated Condition A and Positively activated
condition B.
Is there a way to exclude the negatively activated voxels from the
Condition A vs Passive and Condition B vs Passive contrasts when looking at
Condition A vs Condition B? I would like to do this statistically, not just
at the map level.
Thank you for your help!
Maya