Fig. 1: Overview of the whole-brain model and the choice of optimization target.
From: Transient destabilization of whole brain dynamics induced by N,N-Dimethyltryptamine (DMT)
A Dynamics of a single node (“Local Model”), consisting of a Stuart-Landau nonlinear oscillator with bifurcation parameter \(a\), and the imaginary and real part of complex variable \(z\) vs. \(a\), showing a transition between stable spirals and limit cycles at \(a\) = 0. B Temporal parametrization of the bifurcation parameter \(a(t)\), given by a gamma function with parameters \(\lambda\) (peak amplitude) and \(\beta\) (peak latency). C Illustration of how the nodes were coupled (“Inter-areal coupling”) following the structural connectivity given by DTI scaled by \(G\) to reproduce the empirical FCD. D Representation of the computation of the FCD matrix, which contains in its \(i,j\) entry the similarity between FC matrices computed over short windows starting at time points \(i\) and \(j\). The diagonal block encased in red indicates the baseline period before the administration of DMT (FCD: functional connectivity dynamics; DMT: dimethyltryptamine; DTI: diffusion tensor imaging).
