I’ve just read ‘Why we sleep’ by Matthew Walker. On the back cover it has the usual ‘OTT quotes to grab your attention’ although with this book I’ve had to retract somewhat on that comment. O’Connell (Guardian) says ‘it’s been an eye opener’ and now I am agreeing with him. McConnachie (Sunday Times) says ‘you’ll never think of your bedtime in the same way again’ and again for me, he’s right.
The book is an absorbing and sobering read.
It has a lovely balance between being readable and yet giving neuroscience or other hard-hitting facts. When I picked it up, I read 120 pages that day as it was fascinating. It was a little bit repetitious but methodically works it way through explaining various aspects and then various consequences. The underlying theme is that we are designed for a different way of life than we currently live and there are consequences to that.
My lasting thought is whether mobiles phones and tablets are the equivalent of 21st century cigarettes: Addictive and carcinogenic.
He talks about how sleep is one of the most stupid things nature could allow us to do as we are so vulnerable, especially when paralysed in REM sleep. Therefore, it must be incredibly valuable. However, he also talks about how with ‘earlier risers’ and ‘night owls’, a group of people can effectively spread who is awake across 20 hours thus only being totally vulnerable for 4 hrs. It also means that for us night owls, early mornings required for work and school are not that healthy. Interestingly, dolphins rest (sleep) each hemisphere of their brain separately so that one half is awake and keeps them alive – being totally asleep underwater isn’t a good option. The info on birds made me smile. For birds that roost together in a line, say on a telegraph wire, everyone gets a full sleep except the ones at each end. They need to keep their outer eye, and therefore opposite brain hemisphere, awake to watch out for predators. So, half way through the night they supposedly turn around by 180o so that they can rest the other half of their brain.
I hadn’t realised that sleep is driven by 3 facets: The circadian rhythm which is our 24hr 15min clock rises and falls twice a day which is why we have a lull around 3pm and 3am. Melatonin release is triggered as the light goes down and is the signal to the rest of the brain to shut down for sleep. Walker has a lot to say about the effects of being on electronic devices, LED lighting and general bright lighting and how much that delays this trigger happening. As the morning light rises the Melatonin concentration reduces and we wake up. So, if you are feeling groggy in the morning then bright light is useful but, in the evening, lower level or mood light is much better. This is one thing I have changed as a result of reading this book – I use lamps or use fewer lights and resist the urge to have brightly lit rooms. I also have the blue light filters on my electronic devices and being strict about switching the m off around 8pm. Even reading on a tablet will push out the melatonin effect verses reading a paper book.
The third item is a chemical called Adenosine which I hadn’t heard of before. Basically, Adenosine starts building up from the point you wake up. Its effect is to build up an ‘urge to sleep’. The longer you are awake the more pressure it puts on you to sleep which is why you start to feel tired after 16hrs awake. Then when you get 8hrs sleep the Adenosine is flushed out from the brain and you wake up refreshed. Any less sleep time and some of the Adenosine remains so that next day you have a higher starting level of it already and thus feel tired more quickly. There appears to be a lot of evidence for the effects of 6 or less hours sleep which he says is effectively self-euthanasia. (He’s very passionate about sleep.)
He covers how learning, memory and cogitative abilities are enhanced or impaired with sleep. This couples with the information in ‘Anxious’ as the proteins that build long-term memory need 4-6hrs to do so either through sleeping or through being more relaxed after learning something otherwise the process is interrupted. A thought for L&D people perhaps.
He quite graphically covers how lack of sleep kills you and a number of the various sleep conditions. Narcolepsy sounds terrible. One aspect is that the switch, which fully paralyses you during REM sleep (except your eyes), is faulty so that with any heightened emotion or startlement it flicks on and at that instance your body paralyses itself. Not a good outcome if you are up a ladder or swimming. Apparently, these people learn to nullify their emotions in order to reduce this happening.
He goes on to talk about how to get a decent night’s sleep (p291) and how to do that sensibly. I have to say having followed one or two relevant items for me, I am getting off to sleep much better these days and I am much more committed to doing that having read this book.
On a lighter note, a colleague sent me through this YouTube video, which covers everything you need to know about the brain and it is hilarious.
And on a final note, at Cambridge University’s 30th Neuroscience Day I attended earlier this month, there was a research poster talking about how their ‘findings show that recalling more specific positive memories has long-lasting effects on cortisol and mood’ (reducing and enhancing respectively). This gives me more conviction when advocating this type of exercise to coachees.
I am off now to set-up the login to my new University Moodle website – 6 months after leaving the other one! Puts swapping banks or internet providers into context.