Category: Sleep

How sleep helps us adapt our memories for future experiences.

Sleep helps to strengthen both old and new versions of an experience, new research shows.

Instead of overwriting old versions of a memory, the brain stores another copy of the same experience.

Sleep keeps both old and new memories alive, which gives memory more flexibility.

Dr Scott Cairney, who led the research said:

“Previous studies have shown sleep’s importance for memory.

Our research takes this a step further by demonstrating that sleep strengthens both old and new versions of an experience, helping us to use our memories adaptively.

In this way, sleep is allowing us to use our memory in the most efficient way possible, enabling us to update our knowledge of the world and to adapt our memories for future experiences.”

For the study people were learning the locations of words on a screen over two learning sessions.

One group slept between learning sessions for 90 minutes, the other did not.

The catch was that some of the words moved between training session.

Those that slept in between had better memory for both the original location and the updated location.

This suggested sleep had had a positive effect on both the new and old version of the memory.

Professor Gareth Gaskell, study co-author, said:

“For the sleep group, we found that sleep strengthened both their memory of the original location as well as the new location.

In this way, we were able to demonstrate that sleep benefits all the multiple representations of the same experience in our brain.”

Curiously, the study may also show how some inaccuracies in memories arise.

After all, if we are carrying around multiple memories of the same thing, then it is easy for us to get confused.

The study was published in the journal Cortex (Cairney et al., 2017).

It almost doubled the amount of times that people awoke during the night.

The blue light emitted by screens damages the length and quality of sleep, new research finds.

Screens that emit redder light, though, do not damage sleep in the same way.

Professor Abraham Haim, one of the study’s authors, said:

 “The light emitted by most screens — computers, smartphones, and tablets — is blue light that damages the body’s cycles and our sleep.

The solution must be the use of the existing filters that prevent the emission of this light.”

Screens are particularly damaging to sleep if used at bedtime.

The screens suppress the secretion of melatonin, the hormone that helps control the body’s sleep-wake cycle.

One of the ways blue light damages sleep, the researchers found, was by interrupting how they body regulates its temperature.

Professor Haim said:

“Naturally, when the body moves into sleep it begins to reduce its temperature, reaching the lowest point at around 4:00 a.m.

When the body returns to its normal temperature, we wake up.

After exposure to red light, the body continued to behave naturally, but exposure to blue light led the body to maintain its normal temperature throughout the night — further evidence of damage to our natural biological clock.”

Blue light compared to red light almost doubled the amount of times that people awoke during the night.

Professor Haim said:

“Exposure to screens during the day in general, and at night in particular, is an integral part of our technologically advanced world and will only become more intense in the future.

However, our study shows that it is not the screens themselves that damage our biological clock, and therefore our sleep, but the short-wave blue light that they emit.

Fortunately various applications are available that filter the problematic blue light on the spectrum and replace it with weak red light, thereby reducing the damage to the suppression of melatonin.”

The study was published in the journal Chronobiology International (Green et al., 2017).

Two surveys hint at links between sleep position, personality and the strength of your relationship.

People who are more creative tend to sleep on their left-hand-side, a survey finds.

The survey also found that people who are more extraverted tend to sleep closer to their partners.

In fact, being in closer contact with your partner during sleep was related to having a better relationship.

12% of couples spend the night less than 1 inch apart.

Among these couples, 86% were happy with their relationship.

On the other hand, 2% slept more than 30 inches apart.

Among these couples the amount happy with their relationship dropped to 66%.

Touching was also an important factor, said Professor Richard Wiseman, who conducted the survey:

“One of the most important differences involved touching, with 94% of couples who spent the night in contact with one another were happy with their relationship, compared to just 68% of those that didn’t touch.”

It did not seem to make much difference in which direction couples were sleeping.

The most popular sleeping positions for couples were:

• 42% slept back to back,
• 31% slept facing the same direction,
• and 4% slept facing each other.

A previous survey for a budget hotel chain also examined the link between sleep position and personality.

It found that:

• 41% slept in the foetal position. This was linked to having a sensitive heart and being a little shy.
• 15% adopted the ‘log’, lying on your side with arms by your side. These people were easy-going and social.
• 13% slept in the ‘yearning’ position: same as the log but with arms outstretched. Yearners have open natures, but can be cynical.
• 8% slept like soldiers, on their backs with arms by their sides. These are quiet and reserved people who don’t like to make a fuss, the survey suggested.
• 7% slept in free fall, face down, hands around the pillow. These were somewhat thin-skinned people, often extroverted and brash.

Speaking about his survey, Professor Wiseman said:

“This is the first survey to examine couples’ sleeping positions, and the results allow people to gain an insight into someone’s personality and relationship by simply asking them about their favourite sleeping position.”

The surveys were conducted to publicise a book and a budget hotel chain, respectively. In other words: take with a pinch of salt.

Insomnia is the most common complaint people have about their health.

Insomnia is not just “all in your head”, neuroscientists have found.

For the first time, seven risk genes have been identified for insomnia.

This could be the first step in understanding the biological causes of insomnia.

It helps to show that insomnia is not — as is sometimes claimed — just a psychological condition.

Professor Van Someren, one of the study’s authors, said:

“As compared to the severity, prevalence and risks of insomnia, only few studies targeted its causes.

Insomnia is all too often dismissed as being ‘all in your head’.

Our research brings a new perspective. Insomnia is also in the genes.”

The study of 113,006 people identified seven genes involved in insomnia.

There was also a genetic overlap with two other related disorders: Restless Leg Syndrome and Periodic Limb Movement Disorder.

Genetic overlap was also seen with anxiety disorders, depression and neuroticism.

Dr Anke Hammerschlag, the study’s first author, said:

“This is an interesting finding, because these characteristics tend to go hand in hand with insomnia.

We now know that this is partly due to the shared genetic basis.”

The researchers also looked at the difference between insomnia in men and women.

Professor Danielle Posthuma, another study author, said:

“Part of the genetic variants turned out to be different.

This suggests that, for some part, different biological mechanisms may lead to insomnia in men and women.

We also found a difference between men and women in terms of prevalence: in the sample we studied, including mainly people older than fifty years, 33% of the women reported to suffer from insomnia.

For men this was 24%.”

The study was published in the journal Nature Genetics (Hammerschlag et al., 2017).

Send this survey to Human Resources so we can all have afternoon meetings, our faces adorned with sleep creases.

People who take short naps are happier than those who take long naps or no naps, a new survey finds.

The conclusion comes from a survey of over 1,000 people’s napping habits and their happiness.

66% of people who took naps under 30 minutes reported being happy.

This compared with 56% who took naps over 30 minutes and 60% who did not take naps.

Professor Richard Wiseman, who led the research, said:

“Previous research has shown that naps of under 30 minutes make you more focused, productive and creative, and these new findings suggest the tantalising possibility that you can also become happier by just taking a short nap.

Similarly longer napping is associated with several health risks and again, this is in line with our results.”

Professor Wiseman continued:

“A large body of research shows that short naps boosts performance.

Many highly successful companies, such as Ben & Jerry’s and Google, have installed dedicated nap spaces, and employees need to wake up to the upside of napping at work.”

The research also found that ‘only’ 11% were allowed to take naps at work.

The reason I scare-quote ‘only’ is that I’m surprised anyone is allowed to take a nap at work.

While companies may pay lip service to the nap, many prefer workers to stay at their desks all day and all night.

Whatever.

I suggest sending this research straight to Human Resources.

Every office in the country should shut down between 2 and 3pm so we can all get a little nap.

Then we could all have our 3pm meetings in pyjamas and dressing gowns with sleep creases across our faces.

Wouldn’t that be a great world to live in?

The study was presented at the 2017 Edinburgh International Science Festival by Professor Richard Wiseman.

The herb is central to the traditional home medicine of India called Ayurveda.

Ashwagandha is a herb central to the traditional home medicine of India called Ayurveda.

Its Latin name is W. somnifera, meaning sleep-inducing, and it has been used for that purpose for centuries.

It is sometimes known as “Indian ginseng”.

Modern scientific studies have shown that crude powder of Ashwagandha helps to promote sleep.

Now, new research has revealed the active ingredient.

The Ashwagandha leaf is rich in triethylene glycol (TEG), which scientists have now found helps improve deep sleep.

Although this study was carried out on mice, no side-effects are generally found for humans.

The researchers hope that investigating TEG will revolutionise the treatment of insomnia.

Around 10-15% of the general population suffer from insomnia, rising to 30-60% in the elderly.

Insomnia is linked to many other problems, such as depression, obesity and cardiovascular disease, to name a few.

The active component of Ashwagandha, triethylene glycol (TEG), is commercially available and was found in the study to have the same effect as the crude powder.

The study was published in the journal PLOS ONE (Kaushik et al., 2017).

Organic Ashwagandha image from Shutterstock

A survey of 30,500 people in the UK across 4 years reveals dramatic mental and physical benefits.

Improving sleep quality leads to dramatic mental and physical health benefits, new research finds.

The boost from better sleep is equivalent to winning $250,000 on the lottery or taking an 8-week course in meditation.

Quality of sleep is more important than quantity, the researchers also found.

The conclusions come from a survey of 30,500 people in the UK across 4 years.

The researchers also found that lack of sleep led to greater use of sleep medications and worse emotional and physical states.

Dr Nicole Tang, the study’s first author, said:

“We are far from demonstrating a causal relationship, but the current findings suggest that a positive change in sleep is linked to better physical and mental wellbeing further down the line.

It is refreshing to see the healing potential of sleep outside of clinical trial settings, as this goes to show that the benefits of better sleep are accessible to everyone and not reserved for those with extremely bad sleep requiring intensive treatments.

An important next step is to look at the differences between those who demonstrate a positive and negative change in sleep over time, and identify what lifestyle factors and day-to-day activities are conducive to promoting sleep. Further research in this area can inform the design of public health initiatives.”

The study was published in the journal SLEEP (Tang et al., 2017).

People in the study slept better and their memory was boosted.

Special sounds during sleep can improve sleep and boost memory, new research finds.

The gentle sounds were timed to coincide with natural ‘brain waves’: the waves of electrical activity in the brain.

People in the study were able to recall 26% more words they had learned after being exposed to the sounds during sleep.

Dr Phyllis Zee, a study author, said:

“This is an innovative, simple and safe non-medication approach that may help improve brain health.

This is a potential tool for enhancing memory in older populations and attenuating normal age-related memory decline.”

Deep sleep is known to be critical for memory consolidation: the process by which memories are laid down for the long-term.

However, in older adults the amount of time spent in deep sleep typically reduces.

The study compared the acoustic simulation with sham treatments, which acted as a placebo.

Older individuals — who were targeted for the study — showed better sleep and enhanced memory only after the real acoustic stimulation.

The study’s authors explain their conclusions:

“Acoustic simulation that was phase-locked to sleep slow waves in older adults had systematic effects on sleep indices and performance on a declarative memory test.

These results provide the first demonstration that acoustic stimulation alters SWA [slow wave activity or, colloquially, deep sleep] and can enhance word pair recall in older adults.

These results converge with other findings in young adults indicating that acoustic stimulation during sleep is a promising tool for altering SWA and enhancing sleep-dependent memory consolidation.”

The sound waves in the study were timed to coincide with people’s brain waves.

Their brain waves were read in real time and the sounds timed to help synchronise activity across the neurons.

Dr Nelly Papalambros, the study’s first author, said:

“The idea is to be able to offer this for people to use at home.

We want to move this to long-term, at-home studies.”

The study was published in the journal Frontiers in Human Neuroscience (Papalambros et al., 2017).

Supplement found to buffer the body against stress and improve sleep.

For a long time probiotics — the so-called ‘good bacteria’ in fermented foods and elsewhere — have been linked to all sorts of physical and psychological benefits.

Now the lesser-known prebiotics are getting in on the act.

Prebiotics are dietary fibres found in foods such as:

• Onions,
• leeks,
• artichokes,
• and chicory.

Prebiotic fibre — also available as dietary supplements — can improve the health of your gut by helping beneficial bacteria to multiply.

New research has found that prebiotics can help improve sleep and protect the body against stress.

Dr Agnieszka Mika, one of the study’s authors, explained:

“Acute stress can disrupt the gut microbiome, and we wanted to test if a diet rich in prebiotics would increase beneficial bacteria as well as protect gut microbes from stress-induced disruptions.

We also wanted to look at the effects of prebiotics on the recovery of normal sleep patterns, since they tend to be disrupted after stressful events.”

The study, carried out on rats, found that prebiotics increased both major types of sleep (REM and NREM).

The study’s authors write:

“Given that sufficient NREM sleep and proper nutrition can impact brain development and function and that sleep problems are common in early life, it is possible that a diet rich in prebiotics started in early life could help improve sleep, support the gut microbiota and promote optimal brain/psychological health.”

Dr Robert S. Thompson, the lead author of the research, explained that the rats were also stressed:

“The stressor the rats received was the equivalent of a single intense acute stressful episode for humans, such as a car accident or the death of a loved one.

A next set of studies will be looking exactly at that question – can prebiotics help humans to protect and restore their gut microflora and recover normal sleep patterns after a traumatic event?”

Professor Monika Fleshner, another study author, thinks it is too early to recommend prebiotic supplements for sleep problems.

However, Dr Mika said:

“So far no adverse effects from prebiotics have been reported, and they are found widely in many plants, even present in breast milk, and are already commercially available.”

The study was published in the journal Frontiers in Behavioral Neuroscience (Thompson et al., 2017).

Sleep has important effects on memory.

Going to bed angry really does make it worse, new research finds.

Sleeping after making a fresh bad memory, can give that memory more strength.

Yunzhe Liu, the study’s first author, said:

“This study suggests that there is certain merit in this age-old advice: ‘Do not go to bed angry’.

We would suggest to first resolve (the) argument before… bed.”

In the study 73 students were purposefully given negative memories.

The results showed that it was much more difficult to suppress these negative memories after sleep.

The study may help in the treatment of post-traumatic stress disorder.

The study’s authors write:

“For example, sleep deprivation immediately after traumatic experiences may prevent traumatic memories from being consolidated… and thus provide the opportunity to block the formation of traumatic memories.”

The study was published in the journal Nature Communications (Liu et al., 2016).

Sleep image from Shutterstock