The *0.01 for sub-brick #1 say, shows the scaling of the
data on disk (shorts) to the real values (floats). It does
not related to FDR.
Did you apply a mask in the anova command? If not, the FDR
values will not be accurate. But otherwise, there is an
approximate p->q curve stored in the stats result, which the
GUI takes advantage of.
Regarding the t-test results, the p-value should change as
you change the threshold slider bar. Exactly which volumes
are you looking at?
- rick