模拟飞行任务对飞行员认知能力和心率变异性的影响

摘要

目的 通过持续任务操作建立飞行员脑力疲劳模型,比较任务前后飞行员认知能力的变化,探究任务过程中心率变异性的变化规律,为筛选飞行员功能状态的客观监测指标提供依据.方法 选取30名被试完成持续4h的模拟飞行任务,采用自身前后对照设计,在任务前后完成斯坦福嗜睡量表(SSS)、警戒作业任务模拟(PVT)和注意力转换测试(SAT).在模拟飞行过程中对飞行员的心电指标进行监测.结果 模拟飞行任务后,30名被试SSS评分升高(P＜0.05),PVT和SAT反应时间延长(P＜0.05).在模拟飞行过程中,心率(F=9.81,P＜0.05)和心率变异性的时域指标即相邻R-R间期差值的均方根(RMSSD) (F=4.75,P＜0.05)有显著性变化,心率下降,RMSSD升高;其他心率变异性指标变化差异无统计学意义.结论 认知能力相关指标判断脑力疲劳具有较好的敏感性,心电指标对于判别脑力疲劳具有一定的约束性.%Objective Through the establishment of the model of mental fatigue which was induced by continuous mental workload,compare the changes in cognitive function before and after simulated flight and investigate the pattern of heart rate variability (HRV) during the period of simulated flight,thus providing the foundation of screening objective indices for monitoring mental fatigue.Methods A total of 30 participants were informed to take part in a simulated flight for 4 hours.They were arranged to complete the Stanford Sleepiness Scale (SSS) and two cognitive tests,including psychomotor vigilance task (PVT) and shifting attention test (SAT) before and after simulated flight severally.HRV was recorded continuously during the period of simulated flight.Results After simulated flight,the scores of SSS significantly increased (P＜0.05) and mean reaction times to PVT and SAT were longer compared with presimulated flight (P＜0.05).Heart rate (HR) and RMSSD considered as the time domain index of HRV showed significant difference during the period of simulated flight (F=9.81,F=4.75,respectively,both P＜0.05).The results indicate that HR declined and RMSSD of HRV increased significantly,while no significant differences were found in other time domain component and the frequency domain component of HRV.Conclusions The mean reaction times of cognitive tests are sensitive indices to monitor mental fatigue.However,when the time domain component and the frequency domain component of HRV are applied into monitoring mental fatigue,there are still some limitations in different conditions.