Algorithm 2.

Algorithmic implementation of three-factor STDP.

function processRow(t)

for all j in postSynapticNeurons do

history ← getHistoryEntries(j, told, t)

(tprev, sprev, Dprev, typeprev) ← getPrecedingHistoryEntry(t)

tc ← told

$D_c\leftarrow D_{prev}exp\left(\frac{-(t_c-t_{prev}}{{\tau }_D}\right)$

for all (tj, sj, Dj, typej) in history do

$w_{ij}\leftarrow w_{ij}+\frac{C_{ij}{D}_c}{-\left(\frac{1}{{\tau }_C}+\frac{1}{{\tau }_D}\right)}\left(exp\left(-\frac{(t_j-t_c}{{\tau }_C}\right)exp\left(-\frac{(t_j-t_c}{{\tau }_D}\right)-1\right)$

$C_{ij}\leftarrow C_{ij}exp(-\frac{t_j-t_c}{{\tau }_C})$

if typej is not dopamine then

Cij ← applyPostSpike(Cij, tj, told, si)

Dc ← Dj

tc ← tj

(tj, sj, Dj, typej)←getLastHistoryEntry(t)

$w_{ij}\leftarrow w_{ij}+\frac{C_{ij}{D}_c}{-\left(\frac{1}{{\tau }_C}+\frac{1}{{\tau }_D}\right)}\left(exp\left(-\frac{(t-t_c}{{\tau }_C}\right)exp\left(-\frac{(t-t_c}{{\tau }_D}\right)-1\right)$

$C_{ij}\leftarrow C_{ij}exp(-\frac{t-t_c}{{\tau }_C})$

Cij ← applyPreSpike(Cij, t, tj, sj)

addWeightToRingBuffer(wij, j)

si ← addPreSpike(si, t, told)

told ← t