Dear Stefan, > I am trying to perform a correction at the cluster level when using an > F-test. From checking the archives I understand that this has not yet been > implemented in SPM5. > > Does anybody know a temporary fix for this. Fmristat > (http://www.math.mcgill.ca/keith/fmristat/) has been suggested in an > earlier > mail but I could not find the right tools there either. Well, actually we have written a wrapper program that allows you to calculate cluster p-values for F-contrasts via fmristat. For more details, see http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind0708&L=SPM&P=R1016&I=-3&m =22297 This toolbox is designed for cluster p-value calculation in VBM-like analyses (i.e., under non-uniform smoothness or non-stationarity). But there is a hidden feature in this NS toolbox that allows you to calculate cluster p-values (t- or F-contrasts). This can be done by creating a global variable called ASSUME_STATIONARY and setting it to 1. Here is an excerpt from its documentation. % A hidden feature of spm_list_nS allows calculation of cluster p-values % for t- and F-images under stationarity as well. This is implemented by % the stat_thresh function using the results by Cao [1]. This feature is % activated by creating a global variable called ASSUME_STATIONARY and % set it to 1. Otherwise spm_list_nS calculates cluster p-values under % non-stationarity. % % [1] Cao J, The Size of the Connected Components of Excursion Sets of % Chi^2, t, and F Fields. Advances in Applied Probability 31:579-595 % (1999) Good luck! -Satoru Satoru Hayasaka PhD ---------- Assistant Professor, Public Health Sciences & Radiology Wake Forest University School of Medicine (ph) +1-336-716-8504 / (fax) +1-336-716-0798 (email) shayasak _at_ wfubmc _dot_ edu