O sleep, O gentle sleep, Nature’s soft nurse,
How have I frightened thee.
That thou no more will weigh my eyelids down,
And steep my senses in forgetfulness
How right Shakespeare was!
Air, water, food, sleep. Four essentials of human life. Matthew Walker, a neuroscientist, sets out to prove in this book that sleep is infinitely complex, profoundly interesting and immensely health relevant. He uses science, facts and studies to show that sleep is as important as the other three.
Our sleep-wake cycle is governed by two main factors: Process C or circadian rhythm, reset daily by the sun, through the suprachiasmatic nucleus and Process S, the sleep pressure created by a gradually increasing level of Adenosine. Melatonin is another important player. Its job is to signal the onset of darkness throughout the organism and hence the timing of sleep onset.
Sleep is neither passive nor homogenous. It has its own pattern or architecture consisting of ninety minutes cycles of NREM and REM sleep. Each stage has its own function. NREM weeds out unnecessary neural connections and moves recent experiences from a short term storage to long term storage. REM strengthens neural connections, regulating emotions and fuels creativity. Dreaming, an integral part of sleep, contributes to emotional healing.
How and why sleep evolved with life is not known definitively. What is known is that all organisms sleep-from the active and passive phases of unicellular organisms to the REM sleep of birds and mammals.
One possibility is that the sleep state fixes that which has been upset by wake state. Or, maybe sleep was the first state of life and then wakefulness emerged.
REM sleep, which has evolved last, is highest in humans. The shift of Homo erectus from tree to ground sleeping increased REM (which is accompanied by atonia) leading to increase cognitive creativity, emotional intelligence, social complexity and a rapid evolutional rise to power.
The benefits of a good sleep and the deleterious effects of sleep deprivation are well documented. Hence, why we should sleep well is a no brainer.
How we should sleep is also important. Modern man has a monophasic pattern. However, for eons, humans have had a biphasic pattern and numerous studies have shown immense benefits of an afternoon nap.
Sleep architecture is equally important. Certain diseases have been strongly associated with sleep architecture disruptions eg. Autism has a 30 to 50% decrease in REM sleep. Sleep and its effects on neurological and psychological disease processes is an exciting field of research.
Lastly, the author makes an impassioned plea to incorporate lifestyle changes, taking advantage of our scientific knowledge of sleep –
Avoid sleeping pills as they effectively knock out the higher cortical regions
Let the child sleep: no matter what the age, the longer the child sleeps more is the intellectual development
Drowsy driving is more dangerous than drunk driving.
In summary, this book is about reclaiming one of our most fundamental physiological functions. Give sleep state equal importance as the wake state.
Comments