Christine and Bruce, the first and last authors, have a previous paper on Cyclopean Edge Responses in Macaque V2 (J Neurosci, 2006, 26:7581-7596 ) , showing that many V2 cells respond to depth edges in random-dot stereograms. They suggested there that the responses they observed could result from a simple feedforward scheme in which V2 neurons receive inputs from several V1 subunits with different disparity selectivity. In this paper, we carried out quantitative modelling demonstrating this. I like this paper because much of my work has been on modelling the properties of neurons in V1. It's nice to feel that we can begin to trace how those calculations are then used beyond V1 to result in our depth perception.