Hello I have two related questions:
1) Is there a way to easily run an FDR correction at a specified cluster level rather than the voxel level?
I would like to have enough power for my 3dANOVA to pick up on significant differences across three conditions. When I run alphasim it suggests a pvalue/cluster size that are too high to detect significance. Likewise when I look for q<.05 in the GUI, the p value is prohibitively high when considering 34549 voxels (go figure). It seems to me that if I were able to do a FDR correction for clusters >= 9 voxels, I may have a more manageable statistical threshold. If there is no direct way to do this currently, do you have any ideas for a work around?
2) I am currently considering running my 3dANOVA with an OR_MASK comprised of my three conditions (vs. rest) at an alphasim corrected threshold of alpha <.05 (this would reduce my voxels from 34549 above to 6752 voxels more active in any or all conditions versus rest). This is intuitively appealing to me, however I know of no precedence for doing this, does anything seem off about using an approach such as this?
Any other suggestions are quite welcome in terms of executing very exploratory analyses comparing whole brain activation across three conditions. Thanks!
