Dear Andrew,

Thank you for a wonderful tool!

I'm interested in the following text from the NBS reference manual:

"A common heuristic is to threshold the set of connectivity matrices at the group level and exclude connections that do not exceed the given threshold. For example, a preliminary one-sample t-test can be applied to each connection to assess whether the mean value of connectivity strength differs from zero. Connections that do not differ from zero are then excluded."

Do you recommend such an approach? Should we not be concerned that selecting connections based on group 'extremes' will lead to an inevitable conclusion that the other group will be less extreme, and that therefore we are biasing our statistical analysis when we use NBS. I am thinking of it as something like regression toward the mean, where we inevitably are generating group differences by selecting connections that are defined by extremes in any one group. Somehow it seems like between group differences are not independent from single group differences from 0.

Can you explain how I might be thinking about this incorrectly?

Do you have citations for papers that you think have implemented such a thresholding approach in a sound manner?

Thanks!