Hi Supreet
This is a very basic and important question, that pertains to TBSS but also fMRI and VBM analysis. If you have done fMRI analysis with FSL, this is exactly the same.
If not, you can find more information about this on the Randomise wiki: http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Randomise/UserGuide.
The TFCE_corrp_tstat has all the information you need for each contrast you made. It has the t-values for each of the significant peaks you get (if you got anything significant).
To view and use the statistics you got, the Randomise wiki has this to say about it:
"When viewing the 1-p results in FSLView the min/max display range should be set to 0.95/1.0 so that values less than 0.95 (equivalent to p>0.05) are not shown. If these are corrected values (i.e. corrp) then the visible areas correspond to the statistically significant regions."
This is what you use to visualize the clusters and make pictures for publication (if you want). But it needs to have the correct min/max values. If you see nothing after correcting the values, there are no significant clusters.
"To report cluster results (size, maxima, locations, labels) you can use the cluster and atlasquery tools."
As said, you can use the function "cluster" from the Terminal to get a report of the significant clusters. For example write:
"cluster -i tfce_corrp_tstat1 -t 0.95 --scalarname="1-p" > cluster_corrp1.txt"
This will give you a text file with the significant clusters, size (in voxels) and locations (x,y,z). This is what you use for publication. Again, if it's blank, you don't have any significant clusters.
Finally, if you want to get information about the localization of the cluster in an Atlas, you can use atlasquery. For example:
"$ atlasquery -a "Harvard-Oxford Subcortical Structural Atlas" -c -22,10,0"
This will give you the area where your cluster is according to an atlas of choice.
Hope this helps.
Best regards
Eduardo
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