1. I am planning to add a seed sphere 6mm cortical and 4 millimeters subcortical and I want to do this with Fsfast using given MNI coordinates from a previous study. I am wondering if there is a command on fsfast to achieve that, I have gone through the connectivity analysis but couldn't quite figure a way to do that. 
  1.  Also I want to add a covariate (behavioural score) to my second level connectivity map. I want to use fsfast for consistency sake. If I can be pointed to the command it will be very helpful. 
Thanks, 

Reuben N. Addison

Postdoctoral Fellow 

Brain Recovery Lab

MGH Institute of Health Professions 

Charlestown Navy Yard | 36 1st Avenue, Boston MA 02129