Fig. 4

Spike triggered averages (STAs) for Type I (a) and Type II (c) ML models together with the corresponding response in membrane voltage. Artificial signals are generated (the upper panel in b and d) by connecting many copies of the STA with pieces of background fluctuations of different lengths that are known to be incapable of generating a spike. A typical response of a Type I (b) or a Type II (d) ML model to such a signal is shown in a raster plot. Noise coefficients ${\delta }_1$ and ${\delta }_2$ for Type I and Type II are as in Figs. 3b, d. The reliability measure R is calculated and marked in the figure for each type