Objective To improve the technology of photic stimulative activation (PSA) and enhance the efficiency of electroencephalogram (EEG) examination in Air Force pilot selection.Methods A new flashlight for PSA was developed by optimizing the current technology and verified in pilot selection.Results Comparing to the old type the improvements of new flashlight included:① the cambered appearance design enabled wider view field covered,the added LEDs and enhanced photic luminance allowed better evoking effect,and those improved the performance of flashlight.②The photic frequency order was optimized by retaining 8,10,13,and 15 Hz but abandoning 6,20,and 30 Hz.③The new flashlight showed more significant photic evoking effects for the suspended abnormal EEG on such indices as photic driving reaction,multiple reaction and abnormal EEG waveform in PSA assessment.But for the diagnosed abnormal the evoking effects with new flashlight on 4 indices had no significant difference with the old one.④The detection rate of PSA photic driving reaction duration time (≤5 s) evoked by the new flashlight increased by 10％ as compared with that evoked by the old one.Conclusions The new PSA technology could significantly enhance the detection rate of the suspended abnormal EEG.It's also helpful on effectively grading the stability of cerebral function.

Objective To study the effects of autonomic nervous biofeedback training on heart rate variabitity (HRV) and blood pressure of the military personnel stationed on plateau and to supply them with psychological support.Methods Seventy-one male military personnel (average age:27.6±6.5 yr) were selected as subjects.They were stationed on plateau of 3780 m for 60 d.Autonomic nervous biofeedback training that combined deep breath with HRV biofeedback was performed on them.HR,HRV and blood pressure of subjects were collected at sitting state and biofeedback state.Only 47 subjects' blood pressures were collected becauseof experimental condition limitation.Results ①Mean heart rate under autonomic nervous biofeedback state was significantly lower than that under sitting state (t=2.010,P＜0.05).Subjects' standard deviation of HRV in N-N interval and low frequency under autonomic nervous biofeedback state were significantly higher than those under sitting state (t 3.700,5.401,P＜0.01).②Ratio of diastolic pressure higher than 90 mm Hg was 31.91％under sitting state.Both systolic pressure and diastolic pressure under biofeedback state were significantly lower than those under sitting state (t=4.062,7.632,P＜0.01).The level of blood pressure was positively correlated to age under both states (r=0.363-0.605,P ＜ 0.05).Conclusions Autonomic nervous biofeedback training can reduce heart rate and blood pressure,but increase HRV of the subjects on plateau.It is suggested to strengthen psychological support for the military personnel stationed on plateau because of its benefits on moderating the hypoxia effects on physiology and improving mental state.

Objective To study on the improvement of cognitive performance in mental fatigue state through biofeedback relaxation at 3780m altitude.Methods Experiments were conducted in 12 male testees who have stayed at 3780 m altitude for 50 d.Mental fatigue state was induced by 90 min successional simulative flight.Then in experiment 1,cognitive performance including multi-task performance,memory scanning,visual reaction time,visual choice reaction time and target tracting were tested after 15min rest.In experiment 2,cognitive performance were tested after 15min biofeedback relaxation.Results In experiment 2,cognitive performance including multi-task performance,visual choice reaction time and memory scanning ((73.28 ± 16.29) scores,(0.54 ± 0.11) s,(0.50 ± 0.12) s,respectively) were significantly better than those in experiment 1 ((68.66 ± 13.14) scores,(0.60 ± 0.13) s,(0.63 ± 0.17) s,respectively) (P ＜ 0.05).Conclusion Biofeedback relaxation can improve cognitive performance in mental fatigue state at 3780m altitude.

Objective To investigate the effects of transcranial micro-electric current physiological training (TMCPT) on cerebral function (CF) in order to provide technology and methods for maintaining and training CF under altitude hypoxia.Methods Forty healthy volunteers served as subjects,who took flight to the altitude and were trained by TMCPT in the condition of altitude hypoxia (3700 m above sea level).Current intensity of TMCPT was limited within safety physiological range.Subjects were trained 2 times per day (one in the morning and the other in the afternoon) and each lasted 5 min.Neurobehavioral ability index (NAI) were respectively observed in rush entry phase (first 10 days after entry) and in various resident phases (resided in plateau for 1,2,3 months respectively).Self-evaluating questionnaire and Pittsburgh sleep quality index were investigated to evaluate the sleep quality in different phases.Results ① In rush entry phase:the subjects' digit scan (DS),memory scan (MS),simple visual reaction time (SVRT),complex visual reaction time (CVRT),pursuit aiming (PA) and consecutive performance (CP) were significantly increased by 10-d TMCPT training (t=1.982 4.412,P＜0.05) as compared with those of the 1st day.②Resident phase:compared to the NAI in 1st month,only subjects' DS,MS,SVRT out of 6 NAIs were significantly increased by 3-month TMCPT training (t=3.744 5.812,P＜0.05) as compared with those of the 1st month.③ Sleep quality evaluation:subjects' sleep quality indexes had significant reduction as compared with those in rush entry phase (t =1.833-3.552,P ＜ 0.05).Conclusions TMCPT can improve CF and sleep quality under altitude hypoxia.It＇s suggested that to take β frequency brain wave feedback training to promote CF,and to take α frequency brain wave feedback training to improve sleep quality.