A Study On Brain Dynamics Of Resting State Based On Chaotic Neural Networks

The brain,which is composed of a large number of neurons,neuron clusters and brain regions to form a complex network,is the most delicate and complex system in the human body.Study on brain dynamics is helpful to the prevention and treatment of brain diseases,and the development of the information technology and the artificial intelli-gence.Brainwaves recorded by electroencephalography(EEG)are bioelectrical signals generated when information is transmitted between neurons.Brainwaves in different bands correspond to different brain activity states,which is an embodiment of brain dynamics.There is no study on the brain dynamics related to brainwaves measured by EEG.It is proved that chaotic behavior exists in brain.The Aihara chaotic neural network model proposed based on the electrophysiological experiment of biological system really manifests the chaotic dynamics characteristics of biological nervous sys-tem.We combined the Aihara chaotic neural network model with the functional brain network constructed by functional magnetic resonance imaging(fMRI)data to explore the dynamic characteristics of brain regions associated with brainwaves from EEG in the resting state.The dynamics of brain regions for 15 volunteers was simulated and the outputs of the networks were analyzed by power spectrum.The statistical results show the alpha rhythm to be the dominant brain state at rest and to appear in most regions of the occipital,medial temporal,frontal,and parietal areas.In contrast,beta waves are found to be active in the regions located either next to the ear or beside the temporal cortex(e.g.,the HES,INS,ROL,STG,and PUT).Finally,"stochastic waves",that are a mix of waves of various frequencies,are found in the PCUN,where the PCUN.L region is more dominant than the PCUN.R in randomness.And brainwave types could not be determined in some regions such as ACG,IFGoperc,ORBsupmed,Ling,and PoCG regions,which indicates the individual differences between individuals’ func-tional networks.Our results also show the brain functional asymmetry.We speculate that the fMRI apparatus noises make beta waves appear next to the ear or beside the temporal cortex.It is those brain regions that have auditory processing functions.The precuneus(PCUN)plays an important role in the interwoven networks related to self-consciousness,some basic spontaneous meditation activities,visual-spatial information processing and episodic memory retrieval,which leads to different types of brainwaves in PCUN at the same time.The results of our study are consistent with the experimental results.Our method provides a way to explore the brain dynamics related to brainwaves measured by EEG.