Dear Roger

Yes it indeed does make sense, thank you so much!

But why does the NiiStat manual say, that the statistical tests are one-tailed?
"NiiStat assumes that any possible relationship between brain data and behavioral scores is monotonic. For example, when analyzing lesion location, we typically make an a-priori one-tailed hypothesis: brain injury leads to impaired behavioral performance."
According to this description I did not expect NiiStat to even look for a positive effect of lesion on behavioral performance...


So in case I have these postive z-socres, before I can rely on them I should adapt p to be < 0.025?

Best,
Magdalena