stdp_dopamine_synapse – Synapse type for dopamine-modulated spike-timing dependent plasticity¶
Description¶
stdp_dopamine_synapse
is a connection to create synapses with
dopamine-modulated spike-timing dependent plasticity (used as a
benchmark model in [1], based on [2]). The dopaminergic signal is a
low-pass filtered version of the spike rate of a user-specific pool
of neurons. The spikes emitted by the pool of dopamine neurons are
delivered to the synapse via the assigned volume transmitter. The
dopaminergic dynamics is calculated in the synapse itself.
Warning
This synaptic plasticity rule does not take precise spike timing into account. When calculating the weight update, the precise spike time part of the timestamp is ignored.
Parameters¶
Common properties |
||
vt |
integer |
ID of volume_transmitter collecting the spikes from the pool of dopamine releasing neurons and transmitting the spikes to the synapse. A value of -1 indicates that no volume transmitter has been assigned. |
A_plus |
real |
Multiplier applied to weight changes caused by pre-before-post spike pairings. If b (dopamine baseline concentration) is zero, then A_plus is simply the multiplier for facilitation (as in the stdp_synapse model). If b is not zero, then A_plus will be the multiplier for facilitation only if n - b is positive, where n is the instantenous dopamine concentration in the volume transmitter. If n - b is negative, A_plus will be the multiplier for depression. |
A_minus |
real |
Multiplier applied to weight changes caused by post-before-pre spike pairings. If b (dopamine baseline concentration) is zero, then A_minus is simply the multiplier for depression (as in the stdp_synapse model). If b is not zero, then A_minus will be the multiplier for depression only if n - b is positive, where n is the instantenous dopamine concentration in the volume transmitter. If n - b is negative, A_minus will be the multiplier for facilitation. |
tau_plus |
ms |
STDP time constant for weight changes caused by pre-before-post spike pairings. |
tau_c |
ms |
Time constant of eligibility trace |
tau_n |
ms |
Time constant of dopaminergic trace |
b |
real |
Dopaminergic baseline concentration |
Wmin |
real |
Minimal synaptic weight |
Wmax |
real |
Maximal synaptic weight |
The common properties can only be set by SetDefaults()
and apply
to all instances of the synapse model.
Individual properties |
||
c |
real |
Eligibility trace |
n |
real |
Neuromodulator concentration |
References¶
Transmits¶
SpikeEvent