Hi Dr. McLaren,

From what I understand about the SPM PPI, we normally need to set up a F test for each subject and adjust for the effect of interest. For gPPI, is this step necessary? If it is, do I only include those as included in the "tasks" for the "omnibus F for PPI analysis"?

And if I would like to extract individual VOI using the nearest local maxia to a group coordinate, is there a way to implement this with gPPI?

Thanks a lot.
Happy Easter!

Adjusting the for the effects of interest removes the effect of the null
space regressors (e.g. motion, bad points, etc.). This step is necessary as
you want to remove any non-neuronal sources of signal in your data before
you deconvolve the data to get the estimate of neural activity. For the
omnibus test, you should include all tasks. This is done by default.

Please see my other email for details on individual VOIs.