Feedback on these two questions would be much appreciated.
Having completed a L>R tbss_sym for a single group using the recommended -1 option in randomize, I then proceeded to test R>L by creating design.mat and design.con files in the glm_gui. In the glm_gui I simply changed the contrast from 1 to -1. Is this correct?
The saved fsf files were used in the randomise statement identical to the original left_minus_right script except the 1 option was replaced with the new design.mat and design.con, where the con file was given a negative sign in the glm_gui:
randomise -i all_FA_skeletonised_left_minus_right.nii.gz -m mean_FA_symmetrised_skeleton_mask.nii.gz –o RgL –d design.mat –t design.con --T2
The results appear to show a higher overall amount of FA rightward asymmetry, though leftward asymmetry is greater is certain areas. Is there an accurate method of determining the percentage of rightward and leftward asymmetry?
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