SDM preparation

Preprocessing

This is the last step of the preparations, and it consists in a) creating an SDM map for each original study; and b) randomizing many times the location of the coordinates of the studies and creating an SDM map for each of the randomized studies.

To preprocess the studies

Press the button [Preprocessing]

or:

Select [Preprocessing] in the Meta-analyses menu, to open the following dialog:

Notes

Please be aware that this will remove the previous meta-analysis in this folder.

Statistical significance of Monte Carlo-based tests might vary slightly if you randomize the studies again. However, it is NOT recommended to repeatedly randomize the studies to find a set of randomizations which produce more liberal thresholds. Remember that the meta-analysis MUST be replicable by other colleagues.

The coordinates used from each file (and their Talairach labels) will be written in a file called pp_(study).log, e.g. pp_Smith2000.log. This is useful for checking that coordinates have been correctly read.

Command-line and batch usage

pp number_of_randomizations

Example:

pp 50

References

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 .

The authors | IoP King's College London | NeuroImageN