Fig. A2.

Plot of possible equilibria for Eq. 24. A: extent of each multivalued feedback function defines the minimum input necessary to perturb the system away from equilibrium, defining the fixation lines. As N → ∞, the stable fixed points become more tightly packed on the interval (r⁻; r⁺). B: when the integrator is mistuned, the fixation lines and the feedback line are no longer parallel. The rate that the integrator accumulates input is approximated by the distance between the center line of the feedback subunits [G̃(Ê)], and the feedback line. However, integration only occurs when the “fixation condition” is no longer satisfied, i.e., when the feedback line is no longer bounded by the fixation lines at the current value of Ê.