Hi
I am running a VBM analysis on a group of 30 subjects.
I would like to check the regression between a test score and the GM of a specific ROI.
I ran the preprocessing stages and then in the 2nd level chose the regression design.
Added all of the subjects smoothed GM volumes and added the vector of the corresponding test score of each subject.
Then defined the contrasts: [0 1] for positive correlation and [0 -1] for negative correlation.
Are these contrasts correct? or should I have defined only "1" for positive and "-1" for negative?
Next I added my ROI mask and found that this region showed significant voxels in the positive contrast.
I need help interpeting and presenting these results:
1. Does this mean that the higher the test score the bigger volume of this ROI?
2. How do I present results of regression? Is there a way to plot the regression line?
I tried doing the following, but I am not sure I am plotting the correct thing:
Plot-> fitted responses -> chose the positive contrast -> adjusted response-> plot against ->an explantory var-> chose my test score var
Thanks
Reut
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