Dear Katie, Forman and Friston independently proposed using spatial extent as a method for correcting for the multiple comparison problem which is why both references are listed in the report.html page. The methods give essentially the same corrected p-values (the P column in the Feat report). Hope that answers your question. All the best, Joe -------------------- Joseph T. Devlin, Ph. D. FMRIB Centre, Dept. of Clinical Neurology University of Oxford John Radcliffe Hospital Headley Way, Headington Oxford OX3 9DU Phone: 01865 222 494 Email: [log in to unmask]