Dear FSLers,
I used FSLVBM for a single-group average with a behavioral measure for over 600 subjects, exactly as explained here:
https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/GLM#Single-Group_Average_with_Additional_Covariate
Fortunately, I got a significant result (FWE-corrected). I would like to report and visualize my results. As I read from the previous discussions, I used cluster to report it:
>> cluster -i tmp_tfce_corrp_tstat4 -t 0.95 --scalarname="1-p" --minclustersize --mm > my_cluster.txt
I found only one cluster. Later I masked my cluster as follows:
>> fslmaths tmp_tfce_corrp_tstat4 -thr 0.95 -bin mask_tmp_tfce_corrp_tstat4
and extracted its volume by this:
>> fslstats mask_tmp_tfce_corrp_tstat4 -V
I used fslmeants to extract mean GM volume for each subject and also eigen variates:
>> fslmeants -i GM_mod_merg_s3 -m mask_tmp_tfce_corrp_tstat4 -o mean_GM_volume.txt
>> fslmeants -i GM_mod_merg_s3 -m mask_tmp_tfce_corrp_tstat4 -o eig_GM_volume.txt --eig
I multiplied volume and each subject's GM_volume. However surprisingly when I tried to compute correlation in MATLAB between extracted GM results and my behavioral data, I could not see any significant correlation. I tried corr(X,Y) either between mean_GM and behavioral data or eig_GM and behavioral data. Both results showed no significant correlation.
Could you please help me to understand what I am doing wrong here?
Sincerely,
Kavous
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