sigmoid_rate_gg_1998 – rate model with sigmoidal gain function¶
Description¶
sigmoid_rate_gg_1998 is an implementation of a nonlinear rate model with
input function as in [1] \(input(h) = ( g \cdot h )^4 / ( .1^4 +( g \cdot h )^4 )\).
It either models a rate neuron with input noise (see rate_neuron_ipn)
or a rate transformer (see rate_transformer_node).
Input transformation can either be applied to individual inputs
or to the sum of all inputs.
The model supports connections to other rate models with either zero or non-zero delay, and uses the secondary_event concept introduced with the gap-junction framework.
Nonlinear rate neurons can be created by typing
nest.Create('sigmoid_rate_gg_1998_ipn'). Nonlinear rate transformers can be
created by typing nest.Create('rate_transformer_sigmoid_rate_gg_1998').
Parameters¶
The following parameters can be set in the status dictionary. Note that some of the parameters only apply to rate neurons and not to rate transformers.
rate |
real |
Rate (unitless) |
tau |
ms |
Time constant of rate dynamics |
mu |
real |
Mean input |
sigma |
real |
Noise parameter |
g |
real |
Gain parameter |
rectify_rate |
real |
Rectifying rate |
linear_summation |
boolean |
Specifies type of non-linearity (see above) |
rectify_output |
boolean |
Switch to restrict rate to values >= rectify_rate |
Note:
The boolean parameter linear_summation determines whether the input from different presynaptic neurons is first summed linearly and then transformed by a nonlinearity (true), or if the input from individual presynaptic neurons is first nonlinearly transformed and then summed up (false). Default is true.
References¶
Sends¶
InstantaneousRateConnectionEvent, DelayedRateConnectionEvent
Receives¶
InstantaneousRateConnectionEvent, DelayedRateConnectionEvent, DataLoggingRequest