Information dynamics of in silico EEG Brain Waves: Insights into oscillations and functions
Fig 9
Comparison of δ − β rhythms coexistence and emergence of dominant β rhythm shows different information dynamics profile.
Panels (A, B) depict maximum PSD in δ, θ, α and β bands and three information measures (Transfer, Redundancy and Differentiation) within Phase II.a for fixed τrec ≈ 180. (A) Excitatory and (B) Inhibitory neuron populations. As observed in Fig 8, information transfer (blue × symbol data), but also Redundancy (green × symbol data) in inhibitory group are maximum for the same μ that maximizes PSD for β rhythms in both populations (vertical dotted line in μ ≈ 4.5). The inhibitory differentiation (magenta × symbol data curve) increases considerable close to the discontinous transition between phase II.b and III (see 7C bottom). Here, we observe the beginning of this behaviour, which are not related to emerging waves in phase II.a. We also observe a first peak of PSD of β waves coexisting with slow waves—cf. panel (E) red PSD—that does not relate with a peak in information transfer (vertical dotted line for μ ≈ 1.8 in panel (B)). In this “waves coexistence” regime we observe a relatively small peak in Redundancy in excitatory neurons but no information transfer (see green × symbol curve and blue × symbol curve on panel (B)). Panels (C, D, E, F) illustrate the averaged membrane potential fluctuations and the corresponding PSDs for a group of excitatory and inhibitory neuron populations for μ ≈ 1.8 (panels C and E) and μ ≈ 4.5 (panels D and F). The membrane fluctuations features are clearly different and, while in (C) we have a rhythm with multiple frequency waves including slow and fast components (i.e. δ − β waves coexistence), in (D) we observe a clear dominant β rhythm regime.