We tend to think of sleep as a positive thing. Not enough of it, and we suffer: our moods drop, and we find it harder to both concentrate on what’s in front of us and remember what’s happened. Being well-rested, on the other hand, is associated with greater ability to communicate, to achievement at home and at work, and to superior recollection of previously learned facts or events.
How did you sleep last night? If the answer is “badly” followed by an uninvited pang of anxiety, look no further for an explanation than a study published this month in Nature Human Behaviour.
A lack of sleep is known to lead to feelings of anxiety, even among healthy people. But the new paper reveals that the amount of “deep” or slow-wave sleep is most pertinent to this relationship. That, the authors conclude, is because slow-wave brain oscillations offer an “ameliorating, anxiolytic benefit” on brain networks associated with emotional regulation.
Poor sleepers may be hoping that with the gradual liberalisation of marijuana laws around the world, a new drug to help them sleep will soon become legally available. Bad news, then, from a new diary study, published in Health Psychology, of people who take cannabis as a sleep aid. While the drug seemed to improve some aspects of sleep, it also led people to feel more tired the next day.
Your personality traits play an important part in how long you are likely to live, as much as, or even more than, other personal factors like your intelligence and your family’s economic background. Now a study in the Journal of Research in Personality has identified a key factor that mediates the personality-mortality link – sleep. Simply put, people with certain personality characteristics are more likely to sleep too little, or too much, or to experience greater sleepiness during the day, and in turn this raises their year-on-year risk of dying (too little or excess sleep, and poor quality sleep, have known links with various health risks, such as cardiovascular disease, depression and chronic inflammation).
“Sleep has been associated with both personality and longevity, yet [before now] no study has investigated whether sleep is a pathway linking personality to objective health outcomes,” say the researchers, led by Shantel Spears at West Virginia University.
We often think of sleep as a chance to switch off from the outside world, leaving us blissfully ignorant of anything going on around us. But neuroscience research has shown this is a fantasy – we still monitor the environment and respond to particular sounds while we’re sleeping (at least in some stages of sleep) – a fact that will be unsurprising to anyone who has woken up after hearing someone say their name.
Now a study published in Nature Human Behaviour has revealed more about the brain’s surprisingly sophisticated levels of engagement with the outside world during sleep. Not only does the sleeping brain respond to certain words or sounds – it can even select between competing signals, prioritising the one that is more informative.
As every parent knows, gentle rocking helps a baby to fall asleep. Now a new study, published in Current Biology by researchers in Switzerland, shows that a rocking bed also benefits adults, extending the time that they spend in deep, slow-wave sleep, helping them sleep more soundly, and increasing their memory consolidation through the night. A related rocking study on mice, conducted by a team involving some of the same researchers, and published in the same journal issue, helps to reveal how rocking might have these effects.
The last time you and your class-mates or co-workers pulled an all-nighter before a deadline, you may have noticed:there are always those lucky individuals who seem to do just fine after a lack of sleep, while others feel drowsy and confused – almost like they had too much to drink.
New research conducted at the German Aerospace Center suggests this could be because alcohol intoxication and sleep deprivation are more similar than we once thought.
In their study published recently in PNAS, Eva-Maria Elmenhorst and David Elmenhorst and their colleagues show how both affect us via a shared mechanism. And what’s more, if you’re sensitive to one, you’re likely to cope poorly with the other as well.
“I have been lost in a daydream for as long as I can remember….These daydreams tend to be stories…for which I feel real emotion, usually happiness or sadness, which have the ability to make me laugh and cry…They’re as important a part of my life as anything else; I can spend hours alone with my daydreams….I am careful to control my actions in public so it is not evident that my mind is constantly spinning these stories and I am constantly lost in them.”
The 20-year-old woman who emailed these reflections to Eli Somer at the University of Haifa, Israel, diagnosed herself with Maladaptive Daydreaming, sometimes known as Daydreaming Disorder. While Maladaptive Daydreaming is not included in standard mental health diagnostic manuals, there are cyber-communities dedicated to it, and “in recent years it has gradually become evident that daydreaming can evolve into an extreme and maladaptive behaviour, up to the point where it turns into a clinically significant condition,” write Somer and Nirit Soffer-Dudek at Ben-Gurion University of the Negev, in a new paper on the disorder, published in Frontiers in Psychiatry.
This is Episode 11 of PsychCrunch the podcast from the British Psychological Society’s Research Digest, sponsored by Routledge Psychology. Download here.
Can psychology help us get a better night’s sleep? Our presenter Ginny Smith hears how worry about sleep is sometimes more of a problem than lack of sleep itself. She gives us some evidence-backed sleep tips and finds out about “sleep engineering” – deliberately manipulating the sleep process to aid memory and enhance its health benefits.