Inhibitory
Excitatory
Local coupling strengths ($\sigma_l$)
$w_{ii}$
$w_{ie}$
$w_{ee}$
$w_{ei}$
Spatial spread
$\sigma_i$
$\sigma_e$
$\sigma_l$
Lateral coupling strengths ($\sigma_{e,i}$)
$a_{ii}$
$a_{ie}$
$a_{ee}$
$a_{ei}$
Time constants (ms)
$\tau_i$
$\tau_e$
Diffusion constants
$D_{u_i}$
$D_{v_i}$
$D_{u_e}$
$D_{v_e}$
Maximum rates
$r_i$
$r_e$
Thresholds
$\theta_i$
$\theta_e$
Stimulus gain
$g_i$
$g_e$
Noise
$N_i$
$N_e$
Adaptation
$\alpha_i$
$\beta_i$
$\alpha_e$
$\gamma_e$
$\beta_e$
Stimulation
$A$
$f$
size
where
wave
Time stepping
skip
$\Delta t$
Boundary
radius
hardness
Firing rate variables $U_e$, $U_i$, $3|U_e-U_i|$
Adaptation variables $U_e$, $U_i$, $3|U_e-U_i|$
Phase space (steady-state $V_{e,i}$)
E-cell firing rate
I-cell firing rate
0
1
0
1
Eigenvalues at selected point: Real; Imaginary
Angular spatial frequency (1/pixels)
Temporal frequency; Lines: multiples of $1/\tau_e$
Click to start
\[
\begin{aligned}
\text{Firing-rates:} &&
\dot{U_e} &= \frac{1}{\tau_e}\big\{ -U_e + \color{cyan}{r_e} f\big[A_e - \theta_e + g_e S(t) - \beta_e V_e\big] \big\}
\color{cyan}{+ D_{U_e}\nabla^2U_e}
\\&&
\dot{U_i} &= \frac{1}{\tau_i}\big\{ -U_i + \color{cyan}{r_i} f\left[A_i - \theta_i + g_i S(t) - \beta_i V_i \right] \big\}
\color{cyan}{+ D_{U_i}\nabla^2U_i}
\\
\text{Synaptic activations:}&&
A_e &= (w_{ee} K_l + a_{ee} K_e) \star U_e - (w_{ie} K_l + a_{ie} K_i) \star U_i
\\&&
A_i &= (w_{ei}K_l +a_{ei} K_e) \star U_e - (w_{ii}K_l + a_{ii} K_i) \star U_i
\\
\text{Synaptic adaptation:}&&
\dot{V_e} &= \frac{1}{\tau_{ve}}(U_e - V_e)
\color{cyan}{+ D_{V_e}\nabla^2V_e},\,\,
\text{ where }\tau_{ve} =
\begin{cases}
\alpha_e & \text{if }V_e< U_e
\\
\gamma_e & \text{if }V_e\ge U_e
\end{cases}
\\&&
\dot{V_i} &= \frac{1}{\alpha_i}(U_i - V_i)
\color{cyan}{+ D_{V_i}\nabla^2V_i}
\\
\text{Interaction kernels:}&&
K_{e,i,l}(x,y)
&\propto \exp\big(\frac{1}{2} \tfrac{x^2}{\sigma_{e,i,l}^2}
+\tfrac{1}{2} \frac{y^2}{\sigma_{e,i,l}^2}\big)
\\&&
\color{cyan}{\text{Cyan: }}&\color{cyan}{\text{extended terms to support reaction-diffusion}}
\end{aligned}
\]
Wave State Demonstration
This page is part of the github.com/michaelerule/neuralfield repository, which collects various implementations of the Wilson-Cowan neural field and similar equations over the years. The project can be browsed as a website here. We used these and similar equations to model flicker-induced geometric hallucinations, optogenetic stimulation in motor cortex, and retinal waves.This code uses webGL shaders and encodes floats as 16-bit fixed point in an ad-hoc way. Results are for demonstration and exploration only and not guaranteed to be especially accurate.
Simulation
Presets