Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for filtering a set of tracts that are predicted to be included in a selected neuro-network. In one aspect, a method comprises: receiving selection data selecting a network of a brain, processing magnetic resonance image data of the brain to identify a set of tracts that are predicted to be included in the selected network, determining a blocking surface for the selected network, comprising: obtaining a set of parcellations for the selected network and determining, based on a respective position in the brain of each parcellation in the set of parcellations, a set of parameters defining the blocking surface, and generating filtered tract data by filtering the set of tracts that are predicted to be included in the selected network to remove tracts that intersect the blocking surface.