Fig. 4: Model-based results obtained from averaged subjects: parameter estimations, firing and FCs.

First, the SCs of individual groups are averaged (young n = 1, old n = 1). Next, 50 independent simulations are performed. a The 3-D maps of metastability and mean-square root-error between FCs (mseFC) are plotted on T_gaba − T_glu parameter plane. The blue stars, marked on the 2D parameter plane, indicate optimal T_glu, and T_gaba values. b Clouds of estimated parameters are shown for young adults and elders, produced by 50 independent simulations. Blue and red circles represent the average values in young and old groups, respectively. c Regional excitatory and inhibitory firing rates are plotted for the estimated average T_glu, and T_gaba values. d Empirical and simulated static FCs are plotted using estimated parameters, taking average over trials. e Empirical and simulated FC dynamics (FCD) are shown in time-versus-time plot. All the simulated results are produced using estimated parameter values.