我們可以從極夜之地學到什麼關於睡眠的知識

In the northernmost parts of the Earth, there are times during winter when the Sun does not rise for several weeks. This phenomenon, known as the polar night, can lead to sleep difficulties for some individuals. However, even amidst this prolonged darkness, it is not entirely devoid of light. Occasionally, the Sun's rays manage to filter through the atmosphere, casting beautiful twilight hues of blue, pink, and purple across the sky. Additionally, the Moon and stars provide illumination, while the snow reflects artificial light, creating a unique 'snowglow' that brightens the surroundings. For those residing in the Arctic, the polar night is an integral aspect of their lives, and many adapt to it remarkably well. Some even claim to experience better sleep during this time. Esther Berelowitsch, a resident of Inari, Finland, expresses her fondness for the polar night, stating, 'Polar night is too short. I wish it lasted for two months. I go to bed earlier and sleep better. ' Yet, not everyone shares this sentiment. For some, the absence of sunlight during winter can lead to feelings of sadness and fatigue, resulting in sleep disturbances. The extended periods of darkness can pose challenges, particularly for those who spend significant time indoors. Nevertheless, Arctic inhabitants have developed coping mechanisms to address the unique sleep challenges posed by the polar night. Research indicates that individuals living in these regions may experience fewer sleep-related issues compared to visitors from warmer climates. So, what insights can we glean from Arctic residents regarding our own sleep patterns? In countries such as Norway, Sweden, Finland, Greenland, Russia, Canada, and Alaska, the Sun remains below the horizon for much of the winter season. The duration of the polar night varies by location; for instance, in Rovaniemi, Finland, the polar night lasts only two days, while in Tromsø, Norway, it extends for approximately six weeks. At the extreme end, military personnel stationed at Alert, a Canadian facility located in Nunavut, experience the polar night for an even longer duration. The combination of limited daylight and frigid temperatures can make winter particularly challenging. One well-known consequence of the dark, cold winter months is Seasonal Affective Disorder (SAD), which affects a significant number of individuals during the shorter days. Symptoms of SAD include low energy, increased appetite, and excessive sleepiness, typically manifesting in the autumn or winter and subsiding in the spring or summer. In Europe, it is estimated that around 8 to 14 million people are affected by SAD, with similar rates observed in the United States. The impact of latitude is evident in communities located within the Arctic Circle, where those living in northern Greenland experience higher rates of SAD compared to their southern counterparts. Inuit communities in the Canadian Arctic also report elevated rates of SAD compared to those further south, with rates significantly higher than those found in southern regions of the United States. However, research on this topic remains inconclusive. Some studies suggest a correlation between symptoms of depression and the amount of sunlight received, while others indicate that how individuals perceive winter may play a crucial role. A study involving 238 participants in Norway found that those who maintained a positive outlook on winter activities, such as skiing and cozy evenings by the fire, reported better overall well-being during the polar night. Furthermore, research indicates that the indigenous Sámi population in northern Norway tends to rely less on medication for sleep compared to the non-Sámi population. The Sámi exhibit a more relaxed approach to sleep, allowing children to self-regulate their sleep patterns rather than adhering to strict bedtimes. This highlights the importance of mindset in relation to sleep quality. Michèle Noach, an artist who divides her time between the UK and Vadsø, Norway, describes the polar night as a time of coziness that makes her want to curl up and sleep. However, Leibowitz suggests that individuals with a negative mindset may struggle more during winter. For instance, those who use bright lights to combat darkness may inadvertently create a stark contrast that intensifies the perception of darkness outside. The amount of light we are exposed to during the day significantly influences our sleep patterns, as it helps regulate the production of melatonin, a hormone that induces sleepiness. The near-constant darkness of the polar night can disrupt melatonin production, leading to challenges for those who must adhere to a fixed daily schedule. Research conducted on military personnel in the Canadian Arctic indicates that it is possible to realign melatonin production with sleep patterns through the use of specialized light visors emitting blue-green light. Many Arctic residents utilize soft lighting in the evenings to prepare for sleep. Håkan Långstedt, a lighting designer based in Helsinki, recommends using low-level lighting during the polar night, stating, 'If you have a lot of darkness, you don't need a lot of light to compensate. ' He emphasizes the importance of gradually reducing light levels as bedtime approaches, allowing the body to transition smoothly into sleep mode. Exercise also plays a vital role in regulating our circadian rhythms and can positively impact sleep quality. Engaging in physical activity shortly after waking and again in the afternoon can help shift sleep patterns. Esther Berelowitsch, who relocated to Inari from Paris, dedicates two hours each day to outdoor activities like walking or skiing during the polar night. She believes it is essential to embrace the limited daylight available. Maintaining a consistent sleep schedule is crucial, especially for those with fixed work hours. Research indicates that individuals tend to go to bed later during winter months. A study conducted in Kiruna, Sweden, revealed that participants went to sleep approximately 39 minutes later in winter compared to summer, resulting in an overall reduction in sleep duration. Cold temperatures and diminished daylight hours can disrupt our internal body clocks, leading to increased daytime sleepiness. Some studies have shown that people experience longer REM sleep during winter months, which is the stage of sleep associated with dreaming. Håkan Långstedt has observed that he sleeps better during the polar night, attributing this to the slower pace of life and the opportunity to engage in meaningful social interactions. Esther Berelowitsch appreciates the polar night for allowing her to slow down and enjoy quiet activities. She finds joy in spending time with friends and family during this season, emphasizing the importance of connection and creativity during the dark winter months. Many Arctic residents embrace the polar night, finding beauty and inspiration in the darkness.