SigmoidalJansenRitCoupling

SigmoidalJansenRitCoupling#

class brainmass.SigmoidalJansenRitCoupling(x, conn, k=1.0, cmin=0.0, cmax=0.005, midpoint=6.0, r=0.56)#

Sigmoidal Jansen-Rit coupling (TVB SigmoidalJansenRit, pre-nonlinearity).

Applies the Jansen-Rit firing-rate sigmoid to each source before the network sum:

\[ c_i = k \sum_j g_{ij} \, \sigma_{\mathrm{JR}}(x_{D_{ij}}), \qquad \sigma_{\mathrm{JR}}(x) = c_{\min} + \frac{c_{\max} - c_{\min}}{1 + e^{\,r\,(\mathrm{midpoint} - x)}}. \]

k is the global coupling strength (TVB G; G ≡ k). The source is whatever the caller prefetches (e.g. the Jansen-Rit y1 - y2).

Parameters:

  • x (PrefetchDelayAt | PrefetchDelay | Prefetch | Callable) – The (optionally delayed) presynaptic source, shaped (..., N_out, N_in).

  • conn (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Connection matrix (N_out, N_in) or square-flattened (N_out * N_in,).

  • k (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Global coupling strength (TVB G).

  • cmin (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Lower asymptote of the sigmoid.

  • cmax (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Upper asymptote of the sigmoid.

  • midpoint (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Half-activation potential.

  • r (Callable | Array | ndarray | bool | number | bool | int | float | complex | Quantity | Param) – Steepness of the sigmoid.

Return type:

Any

See also

SigmoidalCoupling

post-nonlinearity sigmoid.

__init__(x, conn, k=1.0, cmin=0.0, cmax=0.005, midpoint=6.0, r=0.56)[source]#
Parameters:
init_state(*args, **kwargs)[source]#

State initialization function.

update(*args, **kwargs)[source]#