Hello,

I've searched the forum and read previous advice on the steps to include two or more contrasts from the same set of subjects - through the "Combine Images" tool. However, I am not certain about a few details when using the new version. Specifically, if I have coordinate locations from two or more contrasts from the same set of subjects (or mostly overlapping subjects), it is my understanding that I should pre-process these contrasts separately (i.e., each having their own text file) and then use the combine images tool with the t-maps that are created.

1. When pre-processing, an upper and lower estimate are created. Should I combine the upper and lower estimates separately (e.g., Study1A_upper + Study1B_upper = Study1_combined_upper, etc.) or combine both upper and lower files from both contrasts?

2. After creating these combined files, am I correct to understand that I need to use the "Convert Images" step and indicate the degrees of freedom?

3. Finally, do I need to re-process this combined images along with the others I am including in the main analysis? Or can I edit my sdm_maps.txt and sdmpsi_params.xml in some way to have it recognize these combined files?

Thanks for all you do to provide this resource to us all!

Best,
Katie