> Is it possible to get one sided p-values in the GUI?
As you have realized, the p-value underneath the slider bar is two-sided. To obtain the one-sided p, simply divide that p-value by 2. For example, if your targeted one-tailed p-value is 0.01, move the slider bar to get the two-side p-value of 0.02, and the corresponding statistic threshold is what you want for 3dClustSim and clusterization.
> I tried checking the box "pos" (for positive) but it did not have any effect on the p-value.
That box is for turning on and off the display of the Positive Only results.
Gang
