Nonlinear Dynamics of EEG Signal Based on Coupled Network Lattice Model

摘要

EEG signals were expressed as the typical non-stationary signal. More and more evidences were found that both EEG and ERP signals are also chaotic signal from the nonlinear dynamics system. A novel model based on the time-varying coupled map lattice model is proposed for investigating the nonlinear dynamics of EEG under specified cognitive tasks. Moreover, the time-variant largest Lyapunov exponent (LLE) is defined for the purpose of defining quantitative parameters to reveal the global characters of system and extract new information involved in the system. Both simulations and real ERP signals were examined in terms of LLE parameter for studying the signal's dynamic structure. Several experimental results show that the brain chaos changes with time under different attention tasks of the information processing. The influence of the LLE with the different attention tasks occurs in P2 period.