Folkard S, Hume K I, Minors D S, Waterhouse J M, Watson F L
Nature. 1985;313(6004):678-9. doi: 10.1038/313678a0.
It is common knowledge that our feelings of alertness or drowsiness vary throughout the day. Indeed, this diurnal variation is so widely accepted that it has been used to validate the drowsy/alert component of activation obtained from mood adjective checklists. There is, however, some evidence from sleep deprivation and shiftwork studies that this variation is not simply a reflection of our sleep/wake cycle, as might be expected, but is at least partially dependent on an endogenous circadian (approximately 24 h) oscillator such as that proposed to account for the circadian rhythm in body temperature and other physiological variables. Here we have tested this suggestion by separating the body-temperature rhythm from the sleep/wake cycle by progressively shortening artificial time cues (zeitgebers). Our results indicate that the circadian rhythm in alertness can become independent of both the sleep/wake cycle and the rhythm in body temperature. Further, and contrary to our expectations, the results suggest that the sleep/wake cycle exerts less influence on the alertness rhythm than it does on that of temperature.
众所周知，我们一天之中的警觉或困倦程度会有所变化。实际上，这种昼夜变化已被广泛认可，以至于它被用于验证从情绪形容词检查表中获得的激活状态下的困倦/警觉成分。然而，睡眠剥夺和轮班工作研究提供了一些证据，表明这种变化并非如预期的那样仅仅是我们睡眠/清醒周期的反映，而是至少部分依赖于一种内源性昼夜节律（约24小时）振荡器，比如被认为可解释体温及其他生理变量昼夜节律的振荡器。在此，我们通过逐步缩短人为时间线索（授时因子），将体温节律与睡眠/清醒周期分离，从而对这一观点进行了测试。我们的结果表明，警觉性的昼夜节律可以独立于睡眠/清醒周期和体温节律。此外，与我们的预期相反，结果表明睡眠/清醒周期对警觉性节律的影响小于其对体温节律的影响。
