[Freesurfer] statistical power analysis

Hello all,

I have just completed a group analysis of cortical thickness, including running the full Monte Carlo simulation to obtain cluster-wise multiple comparison corrections. Now I would like to know, for the clusters I'm interested in, how best to go about doing a statistical power analysis for an upcoming grant application, based on the completed analysis. Is there some easy way to extract the thickness for all individual subjects for a specified cluster, either for all vertices within the cluster, for the mean of all vertices within the cluster, or even for the peak vertex (maximum group difference), so that I can compute group mean and standard deviations for a measure of effect size?

Thanks,

Don