Table 1.

List of parameters used in the software simulations^a.

νbias	Mean firing rate of bias Poisson spike train	All figures	1000Hz
σ	Noise amplitude	All figures, except Figure 1	3· 10−11 A/s0.5
		Figure 1 (left)	2· 10−11 A/s0.5
		Figure 1 (right)	3· 10−10 A/s0.5
		Figure 1 (bottom)	1· 10−9 A/s0.5
β	Exponential factor (fit)	All figures	2.044· 109A−1
γ	Baseline firing rate (fit)	All figures	8808Hz
τr	Refractory period	All figures	4ms
τsyn	Time constant of recurrent, and bias synapses	All figures	4ms
τbr	“Burn-in” time of the neural sampling	All figures	10ms
gL	Leak conductance	All figures	1nS
urst	Reset potential	All figures	0V
C	Membrane capacitance	All figures	10−12F
θ	Firing threshold	All figures	100mV
W	RBM weight matrix (ϵ ℝNυ × Nh)	Figure 4	N(−0.75, 1.5)
bυ, bh	RBM bias for layer υ and h	Figure 4	N(−1.5, 0.5)
Nυ, Nh	Number of visible and hidden units in the RBM	Figure 4	5,5
		Figures 7, 8, 7	824, 500
Nc	Number of class label units	Figures 7, 8, 7	40
2T	Epoch duration	Figures 4, 7, 8	100ms
		Figure 9	300ms
Tsim	Simulation time	Figure 2	5s
		Figure 4	1000s
		Figure 7	0.2s
		Figure 9	0.85s
		Figure 8 (testing)	1.0s
		Figure 8 (learning)	2000s
τSTDP	Learning time window	Figure 7	4ms
η	Learning rate	Standard CD	0.1· 10−2
		Event-driven CD	3.2· 10−2

^aSoftware simulation scripts are available online (https://github.com/eneftci/eCD.