CAJ | 학술논문

目的通过分析在4种不同高度和5种不同声强条件下P300的潜时及波幅，反应时，得出轻、中度缺氧条件下最佳声强值. 方法 14名受试者在地面及1500 m, 3000 m, 4500 m三个模拟高度（吸低氧混合气体）分别进行5种不同声强值（55, 60, 70, 80, 85 dB）的听觉oddball测试，记录脑电图（EEG）、反应时（RT）及主观感觉，EEG经平均叠加处理提取出脑事件相关电位（ERP）中的P3波幅、潜时. 以P3潜时和RT为主要指标评定脑认知能力，结合主观评价确定最佳声强值. 结果 P300潜时及RT，在地面及1500 m，5种听觉oddball任务声强为55dB时的P300潜时及RT明显长于其它4种声强(P<0.01)，而其余4种声强间则无明显差别. 在3000 m, 5000 m，声强为70, 80, 85 dB时P300潜时及RT明显短于55 dB及60 dB的P300潜时和RT (P<0.01),而主观评价反映80, 85 dB声强刺耳，难以忍受. 结论在地面及1500 m轻度缺氧情况下最佳声强值为60～70 dB；在3000 m及5000 m中度缺氧条件下,最佳声强值为70～80 dB,此时P3潜时及RT最短；缺氧会减慢脑信息加工过程.
목적통과분석재4충불동고도화5충불동성강조건하P300적잠시급파폭，반응시，득출경、중도결양조건하최가성강치. 방법 14명수시자재지면급1500 m, 3000 m, 4500 m삼개모의고도（흡저양혼합기체）분별진행5충불동성강치（55, 60, 70, 80, 85 dB）적은각oddball측시，기록뇌전도（EEG）、반응시（RT）급주관감각，EEG경평균첩가처리제취출뇌사건상관전위（ERP）중적P3파폭、잠시. 이P3잠시화RT위주요지표평정뇌인지능력，결합주관평개학정최가성강치. 결과 P300잠시급RT，재지면급1500 m，5충은각oddball임무성강위55dB시적P300잠시급RT명현장우기타4충성강(P<0.01)，이기여4충성강간칙무명현차별. 재3000 m, 5000 m，성강위70, 80, 85 dB시P300잠시급RT명현단우55 dB급60 dB적P300잠시화RT (P<0.01),이주관평개반영80, 85 dB성강자이，난이인수. 결론재지면급1500 m경도결양정황하최가성강치위60～70 dB；재3000 m급5000 m중도결양조건하,최가성강치위70～80 dB,차시P3잠시급RT최단；결양회감만뇌신식가공과정.
AIM　To explore the most suitable sound intensity for man in light and moderate hypoxia stress. METHODS　Fourteen healthy and well trained students were selected as subjects. They were arranged to perform audio oddball tasks of 5 different sound intensity（55, 60, 70, 80, 85 dB） at four attitudes（Ground, 1500 m, 3000 m， 4500 m）. 486 IBM Personal computer was used to produce different sound intensity tones, which were broadcasted to subjects by ear phone. meter was used to measure sound intensity. The subjects breathed air or low oxygen mixture to simulate different attitudes. EEG data and reaction time (RT) were collected. P300 waves of event-related potential (ERP) were extracted. P300 latency and RT, as the main indexes to measure the brain cognitive response speed, were analysed by using a 2-factor (contrast×attitude) analysis of variance. Finally subject feelings were recorded as another important index of evaluation. RESULTS　At ground and 1500 m when sound intensities were 60, 70, 80, 85 dB, P300 latency and RT were significantly shorter compared with 55 dB (P<0.01). But there were no significant differences of P300 latency and RT among them. At 3000 m and 1500 m when sound intensities were 70, 80, 85 dB, P300 latency and RT were significantly shorter compared with the other two's (P<0.01) while significant distinctions among theirs were not found. According to subject feelings sound intensities above 80 dB were unbearable. So the most suitable sound intensity for ground and light hypoxia is 60～70 dB; while for moderate hypoxia it maybe 70～80 dB. CONCLUSION　In light hypoxia stress the most suitable sound intensity is 60～70 dB whereas in moderate hypoxia it is 70～80 dB.