Fundamental Dynamical Modes Underlying Human Brain Synchronization

Figure 1

After a narrow band filtering of the intracranial EEGs in the delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta 1 (13–20 Hz), beta 2 (20–30 Hz), and gamma (30–50 Hz) frequency bands, local- and long-range synchronizations were, respectively, estimated by the spectral power of each recording contact and by the mean phase-locking values (PLV) between every contact and all the others. This computation allows the characterization of the multifrequency synchronization patterns of each time window 𝑡 as a vector S(t). (b) Scatter and density plots of 4 successive days (i.e., 96 hours, patient 1), in the space of the first principal components. (c, d) Distributions in the state space across several days and during waking and sleep states. (e) The spectral amplitudes were color coded in the state space, characterizing three main internal frequencies of individual regions in the delta, alpha, and gamma bands.