Dependence of source encoding accuracy on constants. Left panels show the magnitudes of the correlations between sources and responses of a neuron expected to encode source 1: $|corr(st(1),xt1)|$ and $|corr(st2,xt1)|$⁠. The right panels show the magnitudes of the correlations between sources and responses of a neuron expected to encode source 2: $|corr(st(1),xt2)|$ and $|corr(st2,xt2)|$⁠. (A) Dependence on the constant $α$ that controls the excitability of a neuron when $β$ is fixed to zero. The dashed line (0.5) indicates the optimal value of $expαj1$⁠. (B) Dependence on constant $β$ when $α$ is fixed as $αj1,αj0=-ln2,-ln2$⁠. Elements of $β$ were randomly generated from a gaussian distribution with zero mean. The standard deviation of $β$ was varied (horizontal axis), where zero deviation was optimal. Lines and shaded areas indicate the mean and standard deviation of the source-response correlation, evaluated with 50 different sequences.