Julia Dec (MAM S2ENC)
If you’re already home after school, after a long day… look out through the window now: it’s already dark! Winter. Short days, long nights. To add insult to injury, it is raining all the time! It seems to be the best moment to share a couple of interesting facts about an activity to which, on average, we devote 25 years (!) of our lives to – sleep.
Let’s first look at more (or less) scientific definition of sleep. It is a natural state which allows the body to rest, reducing the sensitivity to stimuli, slowing down physiological functions accompanied by a temporary loss of consciousness.
You cannot do without sleep. It is a function of our body, like breathing – impossible to switch off or to replace with something else.
The effects of sleep deprivation
The documented longest sleep deprivation record belongs to Randy Gardner and can be found in the Guinness Book of Records. This 17-year-old from California did not sleep for 264 hours… that’s 11 days! After such a lack of sleep, both his physical and mental capacities were sharply reduced. It was reported that he experienced hallucinations – he mistook a road sign for a human. Moreover, his cognitive capacities were seriously impaired: he suffered from short-term paranoia and psychosis.
Obviously, after what we call ‘pulling an all-nighter’ we will most probably not suffer any of these symptoms. However, already 24-hours sleep deprivation can lead to increased irritability, some light memory deficits, drowsiness and in certain situations, vision and hearing impairments. Some studies compare the effects of 24-hour wakefulness to having a blood alcohol level of 0.1% implying slower reaction times, difficulty in detecting danger, difficulties with maintaining lane position, etc.…
Staying awake all night may be a short-term quick fix before an important test or due date of an assignment, but it is nothing more than ‘borrowing’ the sleep from your body. Be sure it will ask for it back immediately!
The Guinness Book of Records is silent on how long Randy slept after such an insomnia…
Understanding our sleep cycle
Anyway, waking up is never pleasant. One always wants to sleep a minute longer. Have you ever asked yourself why sometimes after a short sleep we wake up refreshed and full of energy, while on other occasions we sleep for a long time, and still wake up tired and in a bad mood? Where do these mood swings come from? There is a scientific explanation for that as well. It turns out that our morning well-being is determined not only by the length of sleep but also by which phase of sleep we woke up in. We distinguish two phases of sleep – both named after behavior of our body: REM (Rapid Eye Movement) and NREM (Non-Rapid Eye Movement).
Sleep phases occur approximately every 90 minutes. Scientists believe that generally, it is better to wake up in the REM sleep phase even after a shorter period of rest than in the NREM after resting longer. A person awakened in the REM phase is well rested and alert, while the one in the NREM, – confused. Usually, our sleep begins with an NREM phase, thus doing simple math, if one wakes up around 6AM, the best time to fall asleep would be around midnight! This isn’t probably the most effective method, and 6 hours of sleep may not be enough for many of us, but why not give it a try?
The mechanics of dreams
When 90 minutes pass from falling asleep, we begin to experience dreams. We lie still, muscles completely relaxed: the body makes no movements in relation to the dream. Fort example, one does not swing one’s legs while dreaming about running away or chasing someone. Instead, the eyeballs work intensely – they move in different directions under closed eyelids. If one dreams of playing tennis, the eyes move as if we are watching the ball, thus the name of the phrase REM – rapid eye movement.
Visually impaired people also dream. According to recent studies, they do not see images in them, but they experience sensations with other senses: smell, touch, and hearing. Most people’s dreams are colorful. Only 12% of us dream in black and white. Apparently, this proportion was much higher prior to the invention of color television.
Night owls and early birds
Some people, like night owls, are in their element only at night: they are better at working or studying. To compensate late night activity, they are usually functioning less well during early mornings. Then there are others – early birds – waking up at dawn, fresh and ready to go. However, these larks (as we call them in several languages), perform less well during late hours.
Historically, especially in agrarian societies, owls were regarded as ‘lazy’ and less productive. Since people used to live according to the rhythm of nature, they had to feed animals and go to the field before night falls. Candles were not cheap, so people were saving them by not staying up long in the night. Somebody waking up late, and not managing to complete his chores during daylight was perceived as a bad farmer and looked disorganized and lazy. The invention of an artificial electrical light source – the bulb – in the late 19th century made the distinction between owls and larks more anecdotical than anything else.
I would like to remain on a rather light tone. I would like to share with you another tittle-tattle, which certainly is to be taken with a grain of salt: apparently, whether we become owls or larks depends on the season in which we were born in. It has been suggested that early birds are born in spring and summer, and owls in autumn and winter. I am not sure I am buying this “theory” – I was born in April, and I am writing this article for you at midnight…
I am finishing this column quite late at night and hope to find myself in the arms of Morpheus soon. I hope you haven’t completely fallen asleep reading my article. Good night and sleep well!