SDM   Seed-based d Mapping
formerly "Signed Differential Mapping"
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SDM calculations

Mean analyses

This procedure calculates meta-analytic means, with their statistical significance based on Monte Carlo randomizations. You can specify a filter for subgroup analyses.

To calculate a mean

Press the button [Mean]


Select [Mean] in the Statistics menu, to open the following dialog:

Dialog picture

Command-line and batch usage

mean filter


MyMean = mean


The p = 0.005 thresholds (for positive and negative differences) obtained after each randomization are saved in a text file called (name_of_the_mean)_z.htm, e.g. MyMean_z.htm. This is useful for studying the stability of the threshold.


(original algorithms): Radua J and Mataix-Cols D. Voxel-wise meta-analysis of grey matter changes in obsessive-compulsive disorder. Br J Psychiatry 2009; 195:393-402. link .

(effect-sizes and variances): Radua J, Mataix-Cols D, Phillips ML, El-Hage W, Kronhaus DM, Cardoner N and Surguladze S. A new meta-analytic method for neuroimaging studies that combines reported peak coordinates and statistical parametric maps. Eur Psychiatry 2012; 27:605–611. link .