Appunti di informatica

Sinapsi predefinite ANNarchy

http://annarchy.readthedocs.io/en/latest/_modules/ANNarchy/models/Synapses.html

DefaultSpikingSynapse, STP, STDP, Hebb, Oja, IBCM

Sono di tipo rate-coded:

DefaultSpikingSynapse
Hebb
Oja
IBCM

Default

http://annarchy.readthedocs.io/en/latest/_modules/ANNarchy/core/Projection.html

By default, the synapse only ensures linear synaptic transmission:

* For rate-coded populations: ``psp = w * pre.r``
* For spiking populations: ``g_target += w`

STP

sinapsi di tipo spinking model con potenziamento e depressione a breve termine, implementata usando il modelllo di Tsodyks, Markram et al.

par	valore	descrizione
tau_rec	100.0	depression time constant (ms)
tau_facil	0.01	facilitation time constant (ms)
U	0.5	use parameter

time constant of the post-synaptic current, nel modello del neurone…

var	descrizione	equazione
x	recovery variable	dx/dt = (1 - x)/tau_rec
u	facilitation variable	du/dt = (U - u)/tau_facil

vocabolario	valore
pre_spike	g_target += w * u * x
	x *= (1 - u)
	u += U * (1 - u)

STDP

Spike-Timing Dependent Plasticity

par	valore	descrizione
tau_plus	20.0	time constant of the pre-synaptic trace (ms)
tau_minus	20.0	time constant of the pre-synaptic trace (ms)
A_plus	0.01	increase of the pre-synaptic trace after a spike
A_minus	0.01	decrease of the post-synaptic trace after a spike
w_min	0.0	minimal value of the weight w
w_max	1.0	maximal value of the weight w

var	descrizione	equazione
x	pre-synaptic trace	tau_plus * dx/dt = -x
y	post-synaptic trace	tau_minus * dy/dt = -y

Vocabolario eventi	valore
pre_spike	g_target += w
	x += A_plus * w_max
	w = clip(w + y, w_min , w_max)
post_spike	y -= A_minus * w_max
	w = clip(w + x, w_min , w_max)

Table of Contents

Sinapsi predefinite ANNarchy

Default

STP

STDP