I have some questions about using monte carlo sim in qdec:

First of all, I just want to verify it's ok to use the simulation with a whole-brain analysis and not just an ROI analysis.

Second, I'm a bit confused about how to calculate the p-threshold for my max clusters. Looking here: http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/GroupAnalysisClusterSummary

tells me how to calculate the p-value of my clusters, but according to the page, max = -log(base10) (pvalue). The example given is the 13th cluster where max = -5.981, and the stated p value is p < .006. I can't figure out how you came up with this p-value, can you please clarify your calculations?

Finally, in qdec when I change my "threshold" from say 1.3 (.05) to 2.0 (.01) I notice the CW Pvalue threshold doesn't change in the terminal output, and remains at .05. Can you please explain this? What exactly am I changing when I change the "threshold" in qdec?

Thank you in advance for your assistance,

Ashley

Ashley A. Shurick