Table 1: The interpretation and value of model parameters.
Here we summarize the parameters used in equation 1–5. Most parameters assume a fixed value, which was introduced by [35]. A “~” indicates that this parameter is manipulated in the present study to explore the behavior of the model or to fit the model to empirical data. For local connectivity, three pairs of values were used in the present study for wEE and wEI, which are (0.7, 0.35), (2, 1), and (2.8, 1). These parameters were chosen from three different regimes of the local model (regime e, d, a in Figure S1–S2), which are dominated by stable fixed points, damped oscillations, and sustained oscillations respectively. wIE matches wEE to provide feedback inhibition [13]. These values fall within a range comparable to that of existing studies [13, 16]. The constant excitatory input IE to the local model ranges between 0 and 1 to demonstrate how the dynamics of a single brain region can be altered by inputs from other regions (Figure 4). When modeling resting brain dynamics using the global model IE is zero, assuming no external input to the brain. G ranges between 0 and 5, used to explore the effect of global coupling on multistability (Figure 4) and to fit the model to empirical data. The range of G used was consistent with that of existing studies [13, 16]. Cij is defined by each subject’s structural connectome. The noise amplitude σ is set to zero for verifying the classification of fixed points, is set to 0.01 when calculating within-attractor coordination, following [13].
| parameter | interpretation | value |
|---|---|---|
| τ E | decay time of NMDA receptor | 0.1 (s) |
| τ I | decay time of GABA receptor | 0.01 (s) |
| γ E | kinetic parameter of excitatory population | 0.641 |
| γ I | kinetic parameter of inhibitory population | 1 |
| a E | parameter of HE | 310 (nC−1) |
| b E | parameter of HE | 125 (Hz) |
| d E | parameter of HE | 0.16 (s) |
| a I | parameter of HI | 615 (nC−1) |
| b I | parameter of HI | 177 (Hz) |
| d I | parameter of HI | 0.087 (s) |
| r max | maximum firing rate | 500 (Hz) |
| w EE | excitatory-to-excitatory coupling | ~ (nA) |
| w EI | excitatory-to-inhibitory coupling | ~ (nA) |
| w IE | inhibitory-to-excitatory coupling | ~ (nA) |
| w II | inhibitory-to-inhibitory coupling | 0.05 (nA) |
| I E | external input to excitatory population | ~ (nA) |
| I I | external input to inhibitory population | 0.1 (nA) |
| G | global coupling | ~ (nA) |
| C ij | structural connectivity between brain regions | ~ |
| σ | noise amplitude | ~ |