The progression of border ownership (BO) assignment for a $3×2$ c shape with and without ambiguity. The top of the figure shows the ground-truth data, with edges colorized by the correct polarity assignment. The bottom portion of the image is split into two columns: with and without ambiguity. Each row shows the network state at a different time step, beginning with the onset of the stimulus and ending with the first iteration of correct polarity assignment. BO responses are accompanied by the percentage of BO neurons that had correct polarity assignments when the result was probed. At $t$ = 2, the polarity assignment is driven by random noise and purely feedforward input. At $t$ = 3, feedback begins to arrive from the grouping and proto-object layers. Note that the grouping neurons are initially responsive for the concavity of the c shape for both networks. The network with ambiguity shows dampening of ambiguous BO neurons starting at $t$ = 3, when feedback input is received from both sides of each neuron. This dampened activity propagates to the grouping neurons at $t$ = 4, which lowers the ambiguity of the BO neurons. At $t$ = 6, the neurons are fully unambiguous, and the correct assignment emerges. Without ambiguity, the assignment in the concavity is both random and muted due to constant competition.