Exploring sleep from A to Zzzzzzz
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A new book from a researcher at Goldsmiths, University of London looks at what we know about sleep and its impact on our waking lives.
While for some people getting to sleep is as easy as shutting their eyes for others it may be a battle or come with its own terrors. Yet there’s a surprising amount we don’t know about this basic need that has a huge influence on our mental and physical wellbeing.
Alice Gregory, Professor in Psychology at Goldsmiths, has spent years studying sleep. In a new book, Nodding Off, she explores the latest sleep science and uses real-life examples to highlight our experiences of sleep and the strange things that can happen when we develop sleep disorders.
I asked Alice about the research behind the book, how our sleep patterns change and problems arise, and any tips on getting babies to nod off…
Pete Wilton: What first got you interested in the science of sleep?
Alice Gregory: I can remember the precise moment I became hooked on understanding more about the science of sleep. It was towards the end of my undergraduate degree in Experimental Psychology and I was attending one of the last lectures of term. It was taken by a new lecturer who was a sleep expert. She argued powerfully how sleep is so often neglected, yet is related to so many aspects of our waking lives. I had learned little about this topic over the course of my degree, and it struck me as a massive oversight. I was left convinced that we need to focus more heavily on sleep when considering mind and behaviour.
PW: How has your research at Goldsmiths influenced Nodding Off?
AG: Much of the research discussed in my new book Nodding Off is led by other scientists, but I’ve also enjoyed describing some of the work that I’ve been involved in. For example, I talk about work on sleep paralysis that I’ve conducted with Chris French (another Professor in the Department of Psychology) and Dan Denis (an ex-Goldsmiths student who is now a Postdoctoral researcher at Harvard Medical School).
Sleep paralysis involves an inability to move just as someone is falling asleep or waking up. It can be associated with hallucinations too and some people find it very frightening. The best explanation is that features of REM sleep (during which we are paralysed and most likely to have vivid dreams) carries over into our waking lives. This topic is under-researched but sleep paralysis is common. We’ve spent time trying to understand more about the factors associated with its occurrence, and it seems that this experience runs in families. It also appears that things that can disrupt our sleep (particularly our REM sleep) can bring on episodes.
PW: What were the most surprising sleep facts you found out while writing the book?
AG: I’ve been studying sleep for a long time so much of what I present in the book is information that I’ve picked up over the years from my own work and reading that of other scientists.
There are so many fascinating sleep-related facts including that dolphins (as well as certain other animals) sleep half a brain at a time – which might be to help them keep track of the environment or to visit the surface of the water to breathe. A friend who proofread my book was particularly intrigued to learn that night-time erections in armadillos occur at a different stage of sleep (NREM) than those in humans (REM)!
Other interesting facts include that a change in sleep timing found in adolescents (a tendency towards a later bedtime and later rise time) appears to be hard-wired - and is reported in adolescents regardless of which country they live in, whether from pre- or post-industrial societies and is found in non-human mammals. Sleep timing suddenly begins to change back at around the age of 20, and that has even been suggested by some scientists to indicate ‘the end of adolescence’. I also think it’s intriguing that age-related changes to our eyes (which as a consequence filter light in a different way) could be linked to sleep problems in older adults.
Whereas in my academic work I focus on empirical research - I wasn’t trying to write an academic book with Nodding Off and wanted it to be accessible to a wider audience, so I spent a lot of time talking to people about their sleep. I also asked lots of other sleep researchers for their thoughts on different topics. This was the most interesting and eye-opening part for me and really brought the science to life. Examples include talking to a railway worker whose job involves a complex pattern of rotating shifts and hearing about how difficult it is to live in this way – such as the effect it has on his relationships with others. I also spoke to a lady in her 70s who was convinced that she had a ghost in her house and was truly petrified until she realised that her experiences were actually likely to be due to sleep paralysis.
PW: How do our sleep patterns and problems tend to vary with age?
AG: Sleep changes throughout our life course in many ways. As an obvious example, there is a trend for our sleep length to reduce as we grow older. Babies can happily easily sleep for 17 hours a day, but this has halved by young adulthood (they are recommended 7 to 9 hours per night).
Sleep changes in other ways too. For example, a sleep cycle may take just 45 minutes in certain premature babies, but is more like 90 minutes in adults. The ratio of REM and NREM sleep also changes as we grow older – and the amount of REM sleep decreases as babies’ age. This might help to provide clues as to the specific roles that different types of sleep play (REM might be particularly key for the developing brain for example). These changes can also bring some reassurance - as specific sleep problems experienced at certain stages of the life - such as NREM-related sleep terrors often experienced in early childhood - are less likely as we get older and our sleep architecture changes.
PW: What links disorders such as sleep paralysis and more ordinary sleep problems?
AG: From reviewing the literature it seems that things that disturb our sleep can sometimes lead to sleep paralysis. In fact, studies in the laboratory have found that if you disturb sleep in specific ways, this can induce episodes of sleep paralysis in certain cases. It’s also true that sleep problems and disorders have been associated with sleep paralysis. This line of work is exciting as it’s possible that improving sleep quality could prevent sleep paralysis occurring – and research is needed to test this idea.
PW: As a sleep scientist and parent what advice do you have for getting a baby to sleep?
AG: This is THE question and if the answer was simple there wouldn’t be endless books, websites, products and articles on this very topic. It’s such an emotive topic too - and parents often feel passionate about their different choices. If you put a baby down to sleep in their crib when they are sleepy but still awake, they can learn that they can fall asleep alone. This can be useful as when they experience natural arousals during the night (as we all do) they are more likely to fall back to sleep without needing input from their caregivers. There are lots of other tips too - and I’ve been involved in a great website www.babysleep.com led by Professor Jodi Mindell Chair of the Pediatric Research Council. It provides freely available advice by experts in the field.
All babies are different, and if a baby is particularly difficult to settle that certainly doesn’t mean that their parents have done anything wrong. It’s helpful to know that things can be improved too. Sometimes just knowing more about babies’ sleep and how it changes over time, can be useful in helping parents cope with disturbed nights in the early years.