help > Displaying overlapping statistics
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Nov 14, 2017  04:11 PM | Josephine Heine
Displaying overlapping statistics
Dear developers, dear community,

I have a mesh of a subcortical brain structure and would like to add the results of two group comparisons as overlays (t-stats, FSL). The areas of these statistics partly overlap. My goal is to show which areas are uniquely affected for [group A vs. controls], which areas are uniquely affected in [group B vs. controls], and which areas overlap in the two. I successfully added the maps to the surface and set the threshold to 0.95 and 1. The statistics are displayed in a shaded way, including the colour bar. Is there any way to get rid of this shading, so that the significant area is only displayed in a single shade of colour?

What I've tried so far is thresholding and binarizing the t-map in FSL, but this procedure did not seem to be compatible with Surfice (as it resulted in a single shade of colour, but the affected area seemed odd, i.e. way too large).

Any help is greatly appreciated.
Thanks for this very useful visualization tool!
Josephine
Dec 5, 2017  01:12 PM | Chris Rorden
RE: Displaying overlapping statistics
For an overlay, if you set the "min" and "max" value as the same, then the entire overlay will be drawn with a single color. You can choose Advanced/Scripting and paste the code below into your script and then choose Script/Run. Again, if you have a pre-thresholded image (where some voxels are artificially set to zero), you need to be very careful about whether you decide to smooth your overlays. You can set this using the "Smooth voxel-based images" in the preferences menu. 

BEGIN
RESETDEFAULTS;
AZIMUTHELEVATION(70, 15);
MESHLOAD('BrainMesh_ICBM152Right.mz3');
OVERLAYLOAD('motor_4t95vol.nii.gz');
OVERLAYMINMAX(1,2,2);
OVERLAYLOAD('motor_4t95vol.nii.gz');
OVERLAYMINMAX(2,-1,-1);
COLORBARVISIBLE(true);
OVERLAYTRANSPARENCYONBACKGROUND(25);
END.