Figure 2

Variability in the activation threshold enhances bimodality in the output signal y. (a-c) A fixed input-output response curve was considered. (d-f) Variability in the activation threshold was introduced. (g-i) Additional variability in the saturation level of the response curve was considered. The simulation details are exactly the same except that the sample size was 10⁴ and, for the Gamma distribution, the value of a was 100 (refer to Figure 1 legend). The variability in the activation threshold and the saturation level was generated from normal distributions.