Fig. 4
Simulated signals with high and low connectivity degeneration accurately reproduce observed N1 evolutions in Low FC and High FC subgroups. A Absolute values of N1 integral from simulated signals according to \(cp\) and \(lp\) values. Each point represents the value of the N1 integral computed from occipital channels from a simulation with a given combination of \(cp\) and \(lp\). Values are normalized for better visualization. B Simulated N1 integral values according to \(lp\), for each \(cp\)<0.5. Values were normalized between 0 and 1 for each \(cp\) separately. Red line represents the best fitting line of the linear regression analysis (r = 0.86, p < 0.00001). Darker blue represents higher \(cp\) values. C Simulated N1 integral values according to\(lp\), for \(cp\)>0.5. Notation is the same as in (B). Red curve represents the best fitting function, a gaussian (r2 = 0.33). While for \(cp\)<0.5, N1 integral monotonically decreased with \(lp\), for \(cp\)>0.5 the evolution resembles an inverted-U shape. D Simulated N1 components in occipital channels for \(lp\) values of escalating intensity, \(cp\)<0.5. E Simulated N1 components in occipital channels for \(lp\) values of escalating intensity, 0.5 < \(cp\)<0.75. F Peak values of simulated N1 components for \(lp\) values of escalating intensity and \(cp\)<0.5 (with the same parameters used in Panel D) compared with experimental peak values of N1 components in the Low FC subgroup. As the \(lp\) value increases, simulated N1 component peaks exhibited the same monotonic decrease as experimental N1 component peaks with increasing cognitive decline severity. G Peak values of simulated N1 components for \(lp\) values of escalating intensity and 0.5 < \(cp\)<0.75 (with the same parameters used in Panel E) compared with experimental peak values of N1 components in the High FC subgroup. Simulated and experimental signals present the same inverted U-shaped evolution. Abbreviations: \(cp\): connectivity parameter; CTR: Control; FC: Functional Connectivity; \(lp\): local parameter; MCI: Mild Cognitive Impairment; SCD: Subjective Cognitive Decline