脑力疲劳对飞行员认知功能的影响及相关认知指标探讨

Influence of mental fatigue on cognitive function in pilots and its related cognitive indexes

目的筛选评估飞行员脑力疲劳的客观指标,为飞行员航卫保障提供依据。方法选取20名男性飞行员,在持续飞行任务前后对其注意力、执行能力和运动控制能力进行评估。运用警戒作业模拟任务(psychomotor vigilance task,PVT)衡量持续性注意力和警觉性,选择注意力测试(choice reaction time,CRT)和注意力转换测试(shifting attention test,SAT)分别考察选择性注意力和注意力转换能力,执行功能评估运用符号译码测试(digit symbol substitution test,DSST),运动控制功能运用手指敲击测试(finger tapping test,FTT)。结果飞行任务前后,PVT分析指标的平均反应时(Mean RTs):飞行前(307.00±6.15)ms,飞行后(349.63±6.65)ms;平均反应时倒数(Mean 1/RTs):飞行前0.003 8±0.000 11,飞行后0.002 9±0.000 12;最慢反应时的10%的倒数(Slowest 10%1/RTs):飞行前(0.002 2±0.000 01)ms,飞行后(0.001 9±0.000 01)ms;以上三项指标飞行前后差异均有统计学意义(P均<0.05)。但最快反应时的10%(Fastest 10%RT)、前跳次数(False Starts)、遗漏次数(Lapses),飞行前后差异无统计学意义(P>0.05)。另外,CRT飞行前后平均反应时分别为(382.93±12.09)ms和(430.42±12.20)ms,SAT飞行前后平均反应时分别为(538.66±12.01)ms和(598.58±13.13)ms,二者飞行前后差异均有统计学意义(P均<0.05)。结论飞行任务后飞行员的平均反应时延长,持续性注意力、选择注意力和注意力转换能力下降;而执行功能和运动控制能力无明显下降。因此注意力指标对脑力疲劳具有较好敏感性。

Objective To screen the objective indicators of evaluating mental fatigue in pilots and provide basis for aeromedical support. Methods Totally 20 male pilots were chosen to participate in cognitive evaluation including attention, executive function and control of movement before and after continuous flight mission. Attention evaluation consisted of alerting and sustained attention measured by psychomotor vigilance task（PVT）, response selection measured by choice reaction time（CRT） and shift of attention measured by shifting attention test（SAT）. Executive function was assessed by digit symbol substitution test（DSST）, and control of movement was measured by finger tapping test（FTT）. Results Significant differences were found in mean reaction time（mean RTs） [pre-flight：（307.00±6.15） ms vs post-flight：（349.63±6.65） ms], mean 1/RTs [pre-flight：（0.003 8±0.000 11） ms vs postflight：（0.002 9±0.000 12） ms] and slowest 10%RTs [pre-flight：（0.002 2±0.000 01） ms vs（0.001 9±0.000 01） ms]（all P〈0.05）. But there was no significant difference in fastest 10%RT, false starts and lapses（P〉0.05）. In addition, the mean RTs of CRT [pre-flight：（382.93±12.09） ms vs post-flight：（430.42±12.20） ms] and SAT [pre-flight：（538.66±12.01） ms vs post-flight：（598.58±13.13） ms] also showed significant differences in our study（P〈0.05, respectively）. Conclusion Pilots show longer mean reaction time and decreased function in sustained, selective and shift of attention after flight mission, which suggests that attention is a sensitive component in assessing mental fatigue among pilots.