Hi Joelle,

Neither image is "thresholded." If you load and view either the con or spmT .nii files, you will see that there is a value at each voxel.

The difference between the images is that the con image gives you the p-value at each voxel, while the spmT image gives you the t-statistic at each voxel.  The functionality is the same as in regular null hypothesis significance testing.  The t-statistic accounts for the difference in observed Beta relative to standard error of the Betas.  The p-value tells you the statistical significance at each voxel; therefore, it accounts for the t-statistic at each voxel as well as the degrees of freedom of the data.

P.S. when you do a second-level analysis, you should always use the con files, not the spmT's.   

On Wed, Sep 30, 2015 at 3:15 PM, Joelle Zimmermann <[log in to unmask]> wrote:

Hi SPMers,

Am I correct that the spmT_0001.nii image is the same glass brain image that I would see when I pick a particular contrast to visualize under results and get the glass brain with the results table under it. Ie - the regions that significantly stand out (based on the t-test) for that particular contrast?

Alternatively, what is actually the con_0001.nii image? Is this the same image just not thresholded for significance?

Thanks,

Joelle