I’ve recently read a fascinating book called “Why We Sleep” by Matthew Walker. The book is an International Bestseller and has the subtitle “The New Science of Sleep and Dreams.” As might be deduced from the subtitle, Matthew Walker is a Sleep Scientist and has been scientifically investigating sleep for many, many years. Although the book is American in origin, for that is where Matthew now lives and undertakes his work, he himself is British, born in Liverpool. Despite him being a scientist, the book is far from dry and beyond understanding. While it has some staggering revelations it is immensely readable and practical.So what are the staggering revelations? Well, primarily the way the brain works during sleep. People might be familiar with the term “REM Sleep”, with REM standing for Rapid Eye Movement, so called because in this form of sleep a person’s eyes can be seen to be rapidly moving under closed eye-lids. This REM Sleep is associated with the times within sleep when we typically dream. The other form of sleep is called “NREM Sleep” – yes, you guessed it, NREM stands for Non-Rapid Eye Movement, and has a totally different function to REM Sleep.
So how does sleep work? During the day we have a build up of a substance called Adenosine within our bodies which brings with it something called Sleep Pressure. Towards the end of day the Sleep Pressure is such that we feel the need for sleep. Signals from our eyes to the brain around dusk also tell the brain that it’s time to head for bed. When we do fall asleep a part of the brain called the Thalamus activates a “switch” which cuts off all sensory input to the brain (this is why it can be hard to rouse someone who is in a deep sleep – the prodding just doesn’t get through to the brain!).
During the night we go through several 90 minute phases of sleep. The first few phases are typified by NREM Sleep where the experiences, information and learning from the day are shifted from our short term memory into long term memory. Evidently the different parts of the brain act in a wave type unison from front to back (I visualise a Mexican Wave here where the information is shifted from short to long term memory). The later phases of sleep are typified by REM Sleep where the brain’s electrical pattern is far more erratic. One of the things that is going on is that links are being made from the new information of the day to previously learned information, thereby providing a more complete learning experience and enhancing our skills. On hearing of this a pianist approached Matthew Walker and said that he now understood why he could practice a new piece of music until late in the evening, still not getting it right, and then in the morning sit down and play it perfectly. REM Sleep had combined new learning with old to master the new skill needed. It’s why the phrase, “Let’s sleep on it” is not such a bad idea when faced with a problem.
There is much more in the book which looks into the way good sleep supports such things as our immune system and emotional wellbeing. The effects of caffeine (not good), alcohol (not good), sleeping pills (surprisingly also not good) and blue light from LEDs/iPad’s (equally not good in the evening) are also covered. He ends the book by giving 12 top tips for good sleep – if you consult the NHS website on sleep many of the tips are there.
There are points within the book where Matthew Walker seems to take a step back, and then attributes the amazing mechanisms of sleep to Mother Nature and Evolution. In contrast, what he has discovered takes me directly to a portion of Psalm 139 in the Bible – “I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well.”
Matthew Walker’s book, in my opinion, is brilliant, well worth anyone reading, and to me his scientific investigation reveals the brilliance of God’s design. Perhaps we need to sleep on it.
May God’s blessing be upon you. Tony Stephens