Research Of Brain Vigilance Regulation Based On Extremely Low Frequency Pulse Magnetic Stimulation

With the rapid development of manned spaceflight in China,many key problems in aerospace engineering research are increasingly remarkable.The special diurnal variation in space,weight loss and isolated claustrophobic environment,as well as mental overload and other factors which would cause mental fatigue,are very likely to impose negative impact on astronauts’ state of vigilance,thereby affecting task performance and even leading to catastrophic accidents.Therefore,the study of rapid and effective technology to improve vigilance has become a hotpot in the field of aerospace ergonomics.As an effective means of regulating brain functions,extremely low frequency pulsed magnetic field(ELF MF)has great potentials to modulate vigilance due to its characteristics of being painless and noninvasive,safe and easy to operate.Vigilance refers to the ability to sustain attention over prolonged periods of time.Based on the previous studies,this paper presented a scientific hypotheses based on the magnetic stimulation to induce the rhythmic changes of brain electroencephalogram signals,and then quickly regulated the vigilance of the brain.The state of vigilance decrement were induced and evaluated by utilizing N-back experiments and Psycho-Vigilance-Test(PVT)in this study.Through comparative analysis between stimulation and control groups,whether magnetic stimulation can effectively mitigate the degradation of vigilance was investigated.Furthermore,subjects’ electroencephalogram(EEG)and electrocardiosignal throughout the whole experiment were collected,and the characteristic variations of these physiological signals induced by ELF MF exposure were analyzed and subjective rating scales were filled before and after PVT.Finally,subjective scale scores,behavioral performance and physiological parameters were comprehensively analyzed to study the feasibility of magnetic stimulation to regulate brain vigilance and its physiological mechanism.In the stimulation group,the EEG power of high frequencies(alpha,beta)enhanced while that of low frequencies(delta,theta)reduced compared to the control group.Additionally,the complexity of a plurality of leads was relatively high and the average aggregation coefficient of brain networks increased in the stimulation group,which indicated that the local transmission efficiency of the network had beenimproved.Heart rate variability(HRV)analysis was conducted mainly in the time and frequency domains.Finding that in the magnetic simulation group,activities of sympathetic nerves were elevated whereas parasympathetic nerves were inhibited.Demonstrating that the activity of the body increased after magnetic stimulation.Taken together,the results showed that magnetic stimulation can induce the rhythmic changes of brain electroencephalogram signals,thus resulting in the regulation of vigilance.The effect of extremely low frequency pulsed magnetic field on brain vigilance was explored in this paper,which proved the feasibility and validity of this method.It laid a theoretical and experimental basis for the future application of this method in manned spaceflight.