I have a question concerning Cluster Extent in SPM 99. When gathering information from our data that was analyzed using SPM 96, we assumed the K value to represent the number of voxels in a cluster. But when analyzing the same group images under SPM 99, the K values were significantly different, although the same clusters appeared on the images. If anyone can clear up this confusion, I would be very grateful. Thank you, Tom Davidson %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%