Bedtime reading with a tablet or smartphone can interfere with a good night’s sleep, some studies and many anecdotal reports suggest. Now researchers have conducted a small experiment to test the idea.

一些研究和个案报告表明，使用平板电脑或手机进行睡前阅读可能会影响睡眠质量。研究人员进行了一个小实验来验证这一说法。

Scientists had nine people spend 10 nights in a sleep laboratory. For five consecutive nights, they read before sleep with an iPad; then they read print for five nights. In both scenarios, they read in a dimly lit room until they felt ready to go to sleep.

科学家让九人在睡眠实验室中度过了10个晚上。他们将连续五个夜晚使用iPad进行睡前阅读，接下来的五个夜晚，他们会阅读印刷品。两种情况下，他们都会在光线昏暗的房间里阅读，直到他们感觉已准备好入睡。

The experiment, described in Physiological Reports, found that when people used iPads instead of reading print, they selected a later bedtime and had a later sleep onset. They also had suppressed levels of melatonin, the hormone that regulates sleep, and delayed time to melatonin secretion. Periods of REM sleep — the rapid eye movements of the dreaming stage of sleep — were reduced when they used the iPad rather than printed material.

根据《生理学报告》(Physiological Reports)中的描述，该实验发现，当人们读的是iPad而非印刷品时，他们的就寝时间更晚，且更晚入睡。他们调节睡眠的荷尔蒙——褪黑素水平受到抑制，分泌时间延缓。而当他们使用iPad而非印刷材料时，REM睡眠时段——也就是睡眠中做梦时的快速眼动阶段——会缩短。

The volunteers also reported feeling less sleepy in the evening, and less alert in the morning after using the electronic device.

志愿者还报告说，在使用电子设备后，他们感觉到晚上的困意减少，早上也没那么清醒。

“These devices are not benign,” said a co-author of the study, Jeanne F. Duffy, a neuroscientist at Brigham and Women’s Hospital in Boston. “They have biological effects on us. They can be bad for adults, but really bad for kids and adolescents who already don’t get enough sleep.”

“这些设备不是良性的，”该研究的共同作者、波士顿布莱根妇女医院(Brigham and Women’s Hospital)的神经学家珍妮·F·达菲(Jeanne F. Duffy)说。“它们对我们有着生物效应。它们对成人有害，但对孩子和已经缺乏睡眠的青少年来说更是有害。”