Campbell S S, Zulley J
Psychophysiology. 1989 Sep;26(5):580-5. doi: 10.1111/j.1469-8986.1989.tb00714.x.
The occurrence of slow wave sleep within spontaneously initiated daytime sleep episodes was studied to examine hypothesized associations with prior wakefulness and circadian factors. There was a strong relationship between measures of slow wave sleep and the proximity of sleep episodes to the maximum of body core temperature. Those sleep episodes that began within 4 hours of the maximum in body core temperature contained significantly more slow wave sleep than did all other daytime sleep periods, approximating proportions typical of nocturnal sleep. Multiple regression analysis revealed no relationship between measures of slow wave sleep and prior wakefulness. These findings are consistent with an hypothesized approximately-12-hour rhythm in the occurrence of slow wave sleep and they underscore the influence imposed on human sleep by the endogenous circadian timing system.
研究了自发开始的白天睡眠阶段中慢波睡眠的发生情况，以检验与先前清醒状态和昼夜节律因素的假设关联。慢波睡眠指标与睡眠阶段距体核温度最高值的接近程度之间存在很强的关系。那些在体核温度最高值后4小时内开始的睡眠阶段所含的慢波睡眠明显多于所有其他白天睡眠时段，接近夜间睡眠的典型比例。多元回归分析显示慢波睡眠指标与先前清醒状态之间没有关系。这些发现与慢波睡眠发生的假设的约12小时节律一致，并且强调了内源性昼夜节律计时系统对人类睡眠的影响。
