Fig. 3: Effects of neonatal versus adult connectome and coupling strength on SGM spectral realizations.

We compared the differential effects of utilizing a neonatal versus adult connectome and strong versus weak long-range coupling (α) on Spectral Graph Model (SGM) spectra realizations across different brain regions (frontal, temporal, parietal, occipital, and whole-brain). The left and right columns demonstrate SGM power spectral density (PSD) realizations instantiated with group-averaged neonatal and adult connectomes, respectively (N = 1000 per connectome). Each subplot shows mean SGM realizations instantiated with weak (red-dotted line) and strong (blue line) α, with 95% confidence intervals (CI) indicated by the corresponding shaded regions. α was sampled uniformly at random between 0.1 to 0.3 for weak and between 0.7 to 0.9 for strong α regimes, respectively. Remaining SGM parameters were uniformly randomly sampled from physiologically-informed prior ranges (Table 1). Qualitatively, there is a broadband increase in spectral power with relatively stronger augmentation in alpha power seen with stronger α. The alpha peak is not as well defined as seen in Fig. 2 due to the effects of PSD averaging. There were subtle differences in PSD distribution resulting from selection of neonate versus adult structural connectome, demonstrated in Supplementary Fig. 3. Distances between normalized mean spectra per connectome were assessed with Jensen–Shannon divergence (JSH). Across all cortical regions, there was a significant difference in the spectral distribution shift induced by α compared to the shift induced by structural connectome, with whole-brain JSH difference of 0.0899 (p < 1.0e−7).