Ellen Shlossberg,
To use your alpha sim results, you need to find the mann-whitney statistic associated with p=.001. To find this number load your threshold subbrick in the lower subbrick selector within the afni define function window, and your amplitude in the first subbrick selector. Slide the threshold slider until your p value displays .001. Use this mann-whitney statistic number in your -1thresh option in 3dmerge, along with your minimum cluster size of 1058. The resulting clusters >= to 1058 will have a p value of .05.
Your thinking souds right, so far.
Christine Smith
