Earlier today, I was surfing the web and came across a term ‘segmented sleep’. Earlier when I talked about awareness, life, activities, my phrases and conjectures were limited to the five letter word ‘sleep’ but the past few minutes, witnessing many adjectives such as polyphasic, segmented, biphasic etc., as prefix to the so common word ‘sleep’ and have left me confused.
The segmented sleep or the bimodal sleep is an interesting approach to sleeping, which can be inculcated in our regular dynamic life, but its grass root knowledge has been derived from the Medieval times, merely from books and literature, and evaluating habitual occurrence. So, what is this complicated segmented sleep?
Segmented Sleep is to sleep in segments i.e., division of sleeping hours into two or more periods, with the phase of wakefulness in-between the periods. ‘First’ and ‘Second’ sleep were the names attributed to the two periods of sleep that a person witnessed. The first is regarded as early slumber while the second is attributed to morning sleep. The span of wakefulness between the two sleep phases was considered a time of quiet, relaxation and intense mental activity.
The industrial revolution has changed many things and one of them is our sleep pattern. The precious night hours we put in our work, catching entertainment, has engraved the perspective “insomnia” in our lives. Many psychiatrists believe that we are compromising our fundamental physiological well-being, falling viciously into the hands of superficial progress and welfare.
If you don’t believe me when I say sleep is important, hear it out from Shakespeare – “Sleep that knits up the ravelled sleeve of care, the death of each day’s life, sore labour’s bath, Balm of hurt minds, great nature’s second course, Chief nourisher in life’s feast.”
The book “At Day’s Close, Night in Times Past” by A. Roger Ekrich is an important resource that proposes, how people would got to sleep for 3-5 hours in the evening as soon as it got dark, also known as the “First” sleep, then wake up for sometime, either lying unconscious on bed, or pray, or have sex, then followed by another 3-5 hours sleep, also known as the “Second” sleep. However, the recent industrialization has forced the mob to work late, altering the sleeping pattern of humans. Humans no longer have segmented sleep, in general. They have adapted to the change of going to bed little late, having a full fledged sleep of longer duration that the individual periods but shorter than the overall sleeping hours, as administered in segmented sleep.
The longer working hours are not primarily held responsible for the lost sleeping pattern replaced by long continuous night hours, but is attributed to artificial lighting. The fact that people used to go to sleep early in the evening, is because of the absence of these electric lights, they reciprocated to the day and night anomaly, sleeping early in winters and a little late in summers.
Charles A. Czeisler, the Harvard chrono-biologist established the effect of modern lightning on sleep. According to his findings, the lightning has affected and altered the levels of melatonin, a hormone helpful in regulating circadian rhythm (a daily cycle of activity observed in many living organisms for a span of 24 hours, also called biological clock). Also, in an experiment conducted at National Institute of Mental Health, Bethesda, it was observed that humans experienced similar segmented sleep pattern when deprived of artificial lights at night.
Even mammals, totally blind such as Spalax maintain their circadian rhythm, regulated as per impact of light-dark cycle.
The newer studies such as Applied Cognitive Studies have revealed the power of sleep cycles, implying that it is not the amount of sleep but indeed the number of sleep cycles you take, makes up for a good night sleep. An average sleep cycle rests for about 90 minutes, and a total of 4-6 sleep cycles are considered enough, and equivalent to 8 hours of sleep.
A website I recently came across “sleepyti.me bedtime calculator“, follows the above ideology and predicts when you should wake up if you sleep at that instant, or the other way round. It gives plenty of options i.e., the time the sleep cycle ends, considering it is best to wake in-between sleep cycles rather than in middle.
So, have a sleep and a good one at that!