研究目的：過去的研究已經證實睡前的光照會影響後續的睡眠，包括增加入睡所需時間以及減少第一個睡眠週期或前半夜的深睡。然而這些研究使用數千勒克斯(lux)的強光或特定波長的單色光且照光時參與者需要維持不動的姿勢或是暴露同一光源下6小時以上的時間，因此實驗情境與現實生活有很大的不同，所以目前還不清楚這些研究結果是否可以類推至現實生活中。本研究將實驗情境貼近日常生活，探討現代化生活的光照是否會對睡眠產生影響。
研究方法：本研究採受試者內設計來進行實驗。以市售3000K和5000K兩種不同色溫的光源進行實驗，將亮度固定在300多勒克斯，並將結果與弱光(<10 lux)進行比較。九名21至31歲的正常參與者維持規律睡眠一星期後，前來實驗室三晚分別接受睡前三小時不同的光照以及整夜的睡眠記錄。在三小時的光照期間，每半小時測量一次參與者的腦波和心跳速率，並要求他們填寫卡羅連斯加嗜睡量表(The Karolinska Sleepiness Scale)。睡眠資料的部分，針對三個依變項進行分析，分別為入睡時間、前兩個睡眠週期的深睡期以及Delta波的頻譜功率。
結果：高色溫光源相較於低色溫光源更能降低主觀睡前嗜睡狀態，並影響後續的睡眠，包括入睡時間較長以及深睡期較短。高色溫情境與弱光相比，除了上述變項同樣有效果外，Theta-低頻Alpha波(5-9Hz)的頻譜功率在5000K的光照後，有出現下降的狀況，但其它腦波的頻譜功率並沒有出現光照效果。心跳速率和前兩個睡眠週期的Delta波頻譜功率在各比較上均不達顯著，此外3000K光照和弱光在所有依變項上的比較均沒有統計上的顯著差異。
結論：本研究將實驗情境貼近日常生活後，仍大致可看到與過去研究類似的結果，即睡前高色溫的光照相對於低色溫，會降低嗜睡程度並影響後續睡眠。另外，現代化生活的光照，與弱光相比，會增加參與者的入睡時間以及減少前半夜的深睡，但室內燈強度的低色溫光源並不會對參與者的睡眠產生這些影響。因此本研究結果建議睡前可選擇低色溫的光源，以避免光照對入睡時間及深睡的影響。 / Objective：Previous studies confirmed that light exposure before sleep has negative impacts on sleep, including increased sleep onset latency and decreased deep sleep in the first sleep cycle. However experimental manipulations in those studies, such as exposure to bright light or to monochromatic light of specific wavelength and participants keeping a constant posture or light exposure for more than 6 hours are very different from daily life situation. It was not clear that whether those results could be generalized to everyday life. In our study, experiment condition was designed to approximate everyday life in order to examine the effect of presleep light exposure on daily life situations.
Methods：The present study adopted within-subjects design. We used fluorescent light of color temperature of 5000K or 3000K in the experiment and the results were compared with dim light. Nine normal subjects participated in the study. They kept a regular sleep schedule during week before experiment. They came to sleep lab on three experiment nights and exposed to different light for three hours before sleep. During light exposure, EEG power, heart rate and subjective sleepiness were assessed every 30 minutes. For the sleep after light exposure, we analysed sleep onset latency, slow-wave sleep (SWS) duration and delta power after light exposure.
Results： Subjective sleepiness decreased, sleep onset latency increased and SWS significantly decreased under color temperature of 5000K compared with color temperature of 3000K and dim light. Theta/low-frequence alpha (5-9Hz) power was lower under the color temperature of 5000K than dim light, but there were no effects of light on other EEG power. Effects of light exposure on heart rate and delta power were not evident. When 3000K compared with dim light, there were no significant differences on all the variables.
Conclusion： Compared with previous experiments, our study showed similar results when experiment condition was close to everyday life. Exposure to light of high color temperature decreases participants，sleepiness and influences their sleep by increasing sleep onset latency and decreasing SWS duration. When compared with dim light, exposure to light of low color temperature does not influence sleep. These findings implies that light of low color temperature should be used before sleep in order to avoid the detrimental effects of light on sleep.
| Identifer | oai:union.ndltd.org:CHENGCHI/G0094752019 |
| Creators | 薛旭任 |
| Publisher | 國立政治大學 |
| Source Sets | National Chengchi University Libraries |
| Language | 中文 |
| Detected Language | English |
| Type | text |
| Rights | Copyright © nccu library on behalf of the copyright holders |
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