Dynamic scaling behavior of human brain electroencephalogram

After filtering out the αα and ββ peaks in the power spectrum of the human brain electroencephalogram signals Y(t′)Y(t′), the probability distribution of the variation ΔY(t′)≡Y(t′+Δt)-Y(t′)ΔY(t′)≡Y(t′+Δt)-Y(t′) exhibits a dynamic scaling behavior. The auto-correlation functions, persistence probabilities and detrended fluctuation functions of the time series |ΔY(t′)||ΔY(t′)| all show a nontrivial power-law behavior. These results indicate that the dynamics of the human brain electroencephalogram is long-range correlated in time.