Fig. 7

Average action in progressively shorter time intervals before the spike threshold is reached for both Type I (a) and Type II (c) ML models. The horizontal axis represents the duration of time over which action is calculated, starting at the time when spiking threshold is reached. The shorter the time interval, the closer it is to the threshold. The thick solid curve represents the average action of reliable SEEs and the thick dotted curves represent the upper and lower limits based on the SD. The thin solid curve denotes the average action of unreliable SEEs and the thin dotted curves mark the upper and lower limits of the SD. The thick solid curves are averages of 400 reliable SEEs and the thin solid curves are averages of 600 unreliable SEEs. The histogram of the values of the gating variable w when the reliable (bold line) and unreliable (thin line) spike trajectories pass through the threshold at $v_{\mathrm{th}}=-20\text{ mV}$ are plotted in b and d for Type I and II models, respectively. Noise coefficients ${\delta }_1$ and ${\delta }_2$ for Type I and Type II are as in Figs. 3b, d