急性高原低氧环境对不同情绪状态脑电功率的影响

Effects of acute high altitude hypoxia on EEG power in different emotional states

目的:探讨急性高原低氧环境对不同情绪状态脑电功率的影响。方法:本研究为双因素多水平试验设计(氧气环境2个水平!情绪类型4个水平)。通过编写情绪图片诱导12名年龄在20~25岁之间的男性被试产生四类不同情绪:低效价低唤醒(LVLA)、高效价低唤醒(HVLA)、低效价高唤醒(LVHA)、高效价高唤醒(HVHA),分别近似于沮丧、轻松、恐惧、快乐四类情绪,并使用Brain Products 32导脑电采集设备采集不同情绪状态下的脑电信号;次日,采用常压低氧舱模拟4 300 m的高原低氧环境,同一批被试在低氧10 h后使用相同试验范式采集脑电信号。对采集来的脑电信号进行功率谱分析(FFT),同时对额叶(F3\Fz\F4)脑电的五个频段(delta、theta、alpha、beta、gamma)进行两因素重复测量方差分析。结果:功率谱分析发现:急性低氧前后,四类情绪状态下alpha波的全脑分布差异主要集中在额叶、顶叶及部分颞叶;HVLA情绪状态下alpha波全脑分布差异最小。两因素重复测量方差分析结果发现:(1)delta、beta频段功率受氧气环境影响显著(P<0.05),低氧环境下功率增强。(2)theta、alpha频段功率指标上,氧气环境和情绪类型交互作用显著(P<0.05),低氧环境下除HVLA情绪状态外,theta、alpha频段功率皆出现了显著增强。(3)两因素对gamma频段影响都不显著(P>0.05)。结论:在四类情绪状态下,氧气环境的变化对大脑活动的影响差异区域主要集中在额叶、顶叶及部分颞叶;低氧环境对沮丧、恐惧、快乐情绪状态有明显影响,低氧与情绪类型对于theta及alpha频段功率的改变具有协同作用。

Objective:To investigate the effects of acute high altitude hypoxia on EEG power in different emotional states.Methods:This study was two-factor within-subject design(2 levels of oxygen environment ×4 levels of emotion type).Twelve male subjects aged between 20 and 25 years old were induced to produce four different types of emotions by emotional picture evoked paradigm:low valence and low arousal(LVLA),high valence and low arousal(HVLA),low valence and high arousal(LVHA),high valence and high arousal(HVHA).Brain Products 32 was used to collect EEG signals under different emotional states.The next day,a constant depressed oxygen chamber was used to simulate a 4 300 m plateau hypoxia environment,and the same group of subjects used the same experimental paradigm to collect EEG signals 10 h after hypoxia.The collected EEG signals were analyzed by power spectrum(FFT),and the five frequency bands(Delta,Theta,Alpha,beta,gamma) of the frontal lobe(F3\Fz\F4) were analyzed by variance analysis of two-factor repeated measurements.Results:FFT analysis found that before and after acute hypoxia,the whole brain distribution of alpha wave in four emotional states was mainly concentrated in frontal and parietal leaves;the distribution of alpha wave in the whole brain was the least in relaxed emotional state.The results of the two-factor repeated measurement ANOVA showed that:(1)the power of delta \ beta band was significantly affected by the oxygen environment(P<0.05),and the power was enhanced under hypoxia.(2)The power index of theta \ alpha band showed a significant interaction between the oxygen environment and emotional types(P<0.05).Except for the HVLA emotional state,the power of theta alpha band was significantly enhanced under hypoxia.(3) The two factors had no significant influence on the gamma band(P>0.05).Conclusion:Under the four kinds of emotional states,the difference of the influence of oxygen environment on brain activity was mainly in the frontal lobe,parietal lobe and part of temporal lobe.Of the four types of emotions,the oxygen environment had the least significant effect on brain activity in HVLA emotional states,while the rest showed significant differences.