Gain function fit.

<p>Left, multiplicative and additive gain function predictions plotted together with the original somatic firing rate for the low Δ<i>E</i><sub>K</sub><sup>+</sup> condition as a function of stimulus orientation relative to target orientation. The ξ values denote the fit parameter that describes the firing rate change either as a gain coefficient or as a gain constant for the multiplicative (ξ<sub>mul</sub>) and additive (ξ<sub>add</sub>) gain transformation, respectively. Predictions were generated by either adding ξ<sub>add</sub> or multiplying ξ<sub>mul</sub> to the tuning curve with no <i>E</i><sub>K</sub><sup>+</sup> change. Errors were assumed Gaussian and reported as ± standard deviations. Right, actual multiplicative and additive gain function fits plotted with the simulated somatic firing rate data with no <i>E</i><sub>K</sub><sup>+</sup> shift (firing rate before) against low <i>E</i><sub>K</sub><sup>+</sup> shift (firing rate after). The original firing rate data was plotted as ± standard deviations on each axis. To fit the data, we have only considered data with nonzero standard deviation.</p> <p>(PDF)</p>