Biophysically grounded mean-field models of neural populations under electrical stimulation
Fig 6
Phase locking of ongoing oscillations via weak oscillatory inputs.
The left panels show heatmaps of the level of phase locking for (a) the mean-field model and (b) the AdEx network for different stimulus frequencies and amplitudes. Dark areas represent effective phase locking and bright yellow areas represent no phase locking. Phase locking is measured by the standard deviation of the Kuramoto order parameter R(t) which is a measure for phase synchrony. White dashed lines correspond to electric fields with equivalent strengths in V/m. (c) Time series of four points indicated in (a) with the excitatory population’s rate in black and the external input in red (upper panels). In the lower panels, the Kuramoto order parameter R(t) is shown, measuring the phase synchrony between the population rate and the external input. Constant R(t) represents effective phase locking (phase difference between rate and input is constant), fluctuating R(t) indicates dephasing of both signals, hence no phase locking. (d) Corresponding time series of points in (b). Both models are parameterized to be in point A2 inside the fast oscillatory region LCEI. Insets show zoomed-in traces from 15 to 16 seconds. For the AdEx network, N = 20 × 103. All parameters are given in Table 1.