午睡剥夺诱发脑力疲劳对认知能力和心率变异性的影响

Effect of metal fatigue induced by nap deprivation on cognitive function and heart rate variability

目的通过建立午睡剥夺的脑力疲劳模型,探究午睡剥夺诱发的脑力疲劳对认知功能和心率变异性的影响,为筛选快速有效的监测指标提供参考依据。方法选取34名受试者在12∶00、15∶00和18∶00分别填写斯坦福嗜睡量表(stanford sleepiness scale,SSS),完成认知能力测试和心率变异性的监测。认知能力测试包括警戒作业任务模拟(psychomotor vigilance task,PVT)、选择性注意力测试(choice reaction time,CRT)、注意力转换测试(shift attention test,SAT)、符号译码(digit symbol substitution test,DSST)、手指敲击(finger tapping test,FTT)。采用重复测量的统计学方法处理数据。结果午睡剥夺后,受试者的SSS评分显著升高(P<0.05),其中15∶00的评分最高,主观疲劳感最明显。评估认知能力的PVT、CRT、SAT、DSST和FTT在午睡剥夺后差异均有统计学意义(P<0.05),在15∶00反应时延长最明显。心率变异性(heart rate variability,HRV)的时域指标相邻R-R间期差值的均方根(root mean square of the successive normal intervals difference,RMSSD)和频域指标高频成分(high frequency normalized unit,HFnu)差异均有统计学意义(P<0.05)。且RMSSD和HFnu在15∶00均表现有显著上升。而低频成分(1ow frequency normalized unit,LFnu)和LF/HF虽有变化趋势,但差异无统计学意义(P>0.05)。结论认知能力指标是监测脑力疲劳较为敏感的指标。将生理指标和认知能力指标相结合可对脑力疲劳评估提供科学依据。

ObjectiveTo gain insights into the effect of mental fatigue on cognitive function and heart rate variability（HRV）in order to provide data for screening objective indices on mental fatigue. MethodsA total of 34 participants were selected to complete the Stanford Sleepiness Scale（SSS）, cognitive tests and HRV monitoring at 12∶00, 15∶00 and 18∶00 respectively. Cognitive tests included the psychomotor vigilance task（PVT）, choice reaction time（CRT）, shift attention test（SAT）, digit symbol substitution test（DSST）, and finger tapping test（FTT）. Statistical analysis was carried out for each variable（SSS, PVT, DSST, SAT, FTT, and CRT）. The scores of SSS and cognitive tests were submitted to repeated measurement for analysis of variance（ANOVA）. ResultsAfter nap deprivation, the scores of SSS significantly increased（P〈0.05）. The highest score occurred at 15∶00, suggesting the increased feeling of metal fatigue. Cognitive function was measured with PVT, CRT, SAT, DSST and FTT（P〈0.05）. Significant difference was observed between these cognitive tests and reactions were the slowest at 15∶00, suggesting that cognitive performance deteriorated compared with 12∶00 and 18∶00. RMSSD as the time component and HFnu as the frequency domain component of HRV showed significant difference（P〈0.05）. HFnu and RMSSD increased at 15∶00, indicating an increased stimulation of the sympathetic and vagus systems. There was no significant difference between LFnu and LF/HF（P〉0.05）. ConclusionMetal fatigue induced by nap deprivation has significant effect on cognitive performance. Thus, cognitive tests are sensitive indices to monitor mental fatigue. The combination of physiologic measures with neurobehavioral measures can play an important role in assessing mental fatigue.