Dear SPM experts, Recently I read about a PET study, in which after the data were processed (SPM2, 2x2x2mm voxel, 8mm smoothing, paired t-test) and a VOI defined, authors used the following way of correction for multiple comparisons: a Bonferroni-corrected cluster-level P value for a cluster in the VOI was calculated as a function of the cluster volume: Pcorr=P*Sv/Cv where Sv = number of voxels in the VOI; Cv = cluster volume. I wonder if this is a safe way to obtain a corrected P value for clusters in a VOI? If it is ok, in which case this method can be preferred over the one used by SPM for cluster p value correction?. Thanks, Victor