SPM “Z” Statistics

Based on region size
- p(nmax>k): probability of having a region of size k occur by chance in the SPM.
Based on voxel value
- Z: Z value for the specified voxel.
- p(Zmax > u): probability of having the specified voxel value (local maximum) occur by chance; corrected for multiple comparisons.
- (uncorrected): probability of having the specified voxel value (local maximum) occur by chance; omnibus (not corrected for multiple comparisons).