Doran S M, Van Dongen H P, Dinges D F
Division of Sleep and Chronobiology, Department of Psychiatry, Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, 1013 Blockley Hall, 423 Guardian Drive, Philadelphia, Pennsylvania 19104, USA.
Arch Ital Biol. 2001 Apr;139(3):253-67.
Nathaniel Kleitman was the first to observe that sleep deprivation in humans did not eliminate the ability to perform neurobehavioral functions, but it did make it difficult to maintain stable performance for more than a few minutes. To investigate variability in performance as a function of sleep deprivation, n = 13 subjects were tested every 2 hours on a 10-minute, sustained-attention, psychomotor vigilance task (PVT) throughout 88 hours of total sleep deprivation (TSD condition), and compared to a control group of n = 15 subjects who were permitted a 2-hour nap every 12 hours (NAP condition) throughout the 88-hour period. PVT reaction time means and standard deviations increased markedly among subjects and within each individual subject in the TSD condition relative to the NAP condition. TSD subjects also had increasingly greater performance variability as a function of time on task after 18 hours of wakefulness. During sleep deprivation, variability in PVT performance reflected a combination of normal timely responses, errors of omission (i.e., lapses), and errors of commission (i.e., responding when no stimulus was present). Errors of omission and errors of commission were highly intercorrelated across deprivation in the TSD condition (r = 0.85, p = 0.0001), suggesting that performance instability is more likely to include compensatory effort than a lack of motivation. The marked increases in PVT performance variability as sleep loss continued supports the "state instability" hypothesis, which posits that performance during sleep deprivation is increasingly variable due to the influence of sleep initiating mechanisms on the endogenous capacity to maintain attention and alertness, thereby creating an unstable state that fluctuates within seconds and that cannot be characterized as either fully awake or asleep.
纳撒尼尔·克莱特曼是第一个观察到人类睡眠剥夺并未消除执行神经行为功能的能力，但确实使得难以维持超过几分钟的稳定表现的人。为了研究作为睡眠剥夺函数的表现变异性，13名受试者在88小时的完全睡眠剥夺（总睡眠剥夺，TSD条件）期间，每2小时在一项10分钟的持续注意力心理运动警觉任务（PVT）上接受测试，并与15名受试者组成的对照组进行比较，该对照组在88小时期间每12小时允许小睡2小时（小睡条件，NAP条件）。相对于NAP条件，TSD条件下受试者之间以及每个个体受试者内的PVT反应时间均值和标准差显著增加。在清醒18小时后，TSD受试者的表现变异性也随着任务时间的增加而越来越大。在睡眠剥夺期间，PVT表现的变异性反映了正常及时反应、漏报错误（即失误）和虚报错误（即无刺激时做出反应）的组合。在TSD条件下，漏报错误和虚报错误在整个剥夺过程中高度相互关联（r = 0.85，p = 0.0001），这表明表现不稳定更可能包括补偿性努力而非缺乏动机。随着睡眠缺失的持续，PVT表现变异性的显著增加支持了“状态不稳定”假说，该假说认为，由于睡眠启动机制对维持注意力和警觉性的内源性能力的影响，睡眠剥夺期间的表现越来越多变，从而产生一种在几秒钟内波动的不稳定状态，这种状态不能被描述为完全清醒或睡眠。
