Sleep - Page 15 of 18

Late-Night Snacking Is A Widespread Habit That May Damage Memory

Learning and memory could be damaged by this common habit.

Learning and memory could be damaged by this common habit.

Habitual late-night snacking could damage a type of memory and learning, a new study suggests.

Eating meals at odd hours has already been linked to metabolic problems.

This, though, is some of the first evidence of potential psychological effects.

Dr Dawn Loh, the study’s first author, said:

“We have provided the first evidence that taking regular meals at the wrong time of day has far-reaching effects for learning and memory.
Since many people find themselves working or playing during times when they’d normally be asleep, it is important to know that this could dull some of the functions of the brain.”

The study, carried out on mice, tested their ability to recognise novel objects.

Those fed when they usually slept showed worse memory performance.

The late-night-snacking-mice also had problems filing the objects away in long-term memory.

Professor Christopher Colwell, one of the study’s author, said:

“Modern schedules can lead us to eat around the clock so it is important to understand how the timing of food can impact cogitation.
For the first time, we have shown that simply adjusting the time when food is made available alters the molecular clock in the hippocampus and can alter the cognitive performance of mice.”

The mice that snacked at night also had worse sleep.

Their sleep was more fragmented and they require more naps during the day.

Researchers will need to carry out tests on human subjects to see if the effect is the same.

However, we already know from other studies that shift-workers under-perform on cognitive tests.

We also know that eating less at night may help to reduce the mental problems caused by lack of sleep.

The study was published in the journal eLife (Loh et al., 2015).

Brain image from Shutterstock

Pets In Bed: Study Reveals If It Helps or Hurts Sleep

Is having a pet in bed beneficial for sleep?

Is having a pet in bed beneficial for sleep?

Having a pet in the bed may benefit some people’s sleep, a new survey suggests.

The conclusion comes from 150 patients at the Mayo Clinic’s Center for Sleep Medicine in Scottsdale, AZ.

They found that just over half of pet owners allowed their pets into the bedroom.

One-fifth of those reported some disruptive behaviours like whimpering, wandering and snoring.

But 41% said their pets did not disrupt their sleep, with some claiming it helped them sleep.

Single people in particular said their pets provided relaxation, companionship and security.

One single 64-year-old woman spoke of feeling more confident with her dog in the bed at her feet.

Another woman said her two small dogs were good bed-warmers.

A cat lover described the animal as providing a soothing presence.

The study’s authors said:

“The value of these experiences, although poorly understood, cannot be dismissed because sleep is dependent on a state of physical and mental relaxation.”

The researchers note, though, that pet owners could have been biased in their responses:

“Respondents appeared eager to disclose whether they owned a companion animal and where it slept but seemed more reluctant to reveal any undesirable consequences.
This response bias may have resulted in these data underreporting the frequency of disrupted sleep.”

The authors conclude:

“Many pet owners view companion animals as family members that they wish to incorporate into as many aspects of their life as possible.
Because humans spend considerable time sleeping, a pet owner’s desire to have animals close at night is understandable.
As more households include multiple pets, the challenge of securing appropriate sleeping arrangements is increased.”

The study was published in the journal Mayo Clinic Proceedings (Krahn et al., 2015).

Pet in bed image from Shutterstock

Interrupted Sleep Has a Fascinating Effect On Some Emotions

The type of sleep linked to feeling more positive emotions.

The type of sleep linked to feeling more positive emotions.

More sleep isn’t always better for your mood.

In fact, more sleep that’s disrupted reduces positive moods more than less sleep that’s uninterrupted, a new study finds.

Uninterrupted sleep is particularly beneficial for the positive emotions of friendliness and sympathy for others.

Dr Patrick Finan, who led the study, said:

“When your sleep is disrupted throughout the night, you don’t have the opportunity to progress through the sleep stages to get the amount of slow-wave sleep that is key to the feeling of restoration.”

The study compared three groups who came into a sleep lab for three nights:

One group were forcibly awakened throughout the night.
Another group had their bedtime delayed.
A final group were left to sleep normally.

People were asked about their positive and negative moods during the day.

After two nights, the different groups started to diverge.

People whose sleep was interrupted had 31% less positive mood during the day.

Those who had their sleep delayed experienced 12% less positive mood.

There was little difference in negative moods.

Naturally those in the study who’d slept solidly also felt more energetic.

So it seems that interrupted sleep mainly dampens the feelings of positive emotions rather than increasing negative emotions.

Frequent awakenings during the night is one of the symptoms of insomnia.

Dr Finan said:

“Many individuals with insomnia achieve sleep in fits and starts throughout the night, and they don’t have the experience of restorative sleep.”

The study was published in the journal Sleep.

Jumping image from Shutterstock

A Fact About Sleepwalking That Few Appreciated — Until Now

One sleepwalker had jumped out of a third-floor window and sustained severe fractures.

One sleepwalker had jumped out of a third-floor window and sustained severe fractures.

Sleepwalkers are unlikely to feel pain while sleepwalking despite suffering horrendous injuries, a new study finds.

Despite that, sleepwalkers are more sensitive to getting headaches and migraines when awake.

Dr. Regis Lopez, who led the study, said:

“Our most surprising result was the lack of pain perception during the sleepwalking episodes.
We report here, for the first time, an analgesia phenomenon associated with sleepwalking.”

The conclusions come from a survey of 100 sleepwalkers.

Amongst sleepwalkers who had injured themselves, 79% felt no pain and the injury did not wake them up.

They only realised they’d injured themselves later in the night or in the morning.

One sleepwalker had jumped out of a third-floor window and sustained severe fractures.

But he hadn’t noticed it until waking later in the night.

Another sleepwalker climbed onto the roof during an episode and fell, breaking his leg.

He felt no pain until he woke in the morning.

Despite this, sleepwalkers were more susceptible to pain during the day.

They were ten times more likely than normal to report migraines and four times more likely to report headaches.

Dr. Lopez said:

“Our results may help to understand the mechanisms of the sleepwalking episodes.
We hypothesize that a dissociate state of arousal may modify the components of sleep-wake behavior, consciousness, and also pain perception.”

The study was published in the journal Sleep (Lopez et al., 2015).

Sleepwalking image from Shutterstock

How The Brain Controls Sleep

Weird ‘zoning out’ sensation when sleepy explained.

Weird ‘zoning out’ sensation when sleepy explained.

Parts of the brain can fall asleep while the rest of the brain stays awake, new research finds.

It might explain the weird sensation of ‘zoning out’ people get when they are trying to avoid falling asleep.

The effect is triggered by a brain structure called the thalamic reticular nucleus (TRN).

The TRN relays signals including a slow oscillating brain wave typical of sleep.

The TRN may be important in how we consolidate new memories.

Dr Laura Lewis, the study’s lead author, said:

“During sleep, maybe specific brain regions have slow waves at the same time because they need to exchange information with each other, whereas other ones don’t.”

Dr Lewis said their animal experience revealed that…

“…when you induce these slow waves across the cortex, animals start to behaviorally act like they’re drowsy.
They’ll stop moving around, their muscle tone will go down.”

The brain circuit could also be responsible for the weird sensation of ‘zoning out’ people get when they are trying to avoid falling asleep.

Dr Lewis said:

“I’m inclined to think that happens because the brain begins to transition into sleep, and some local brain regions become drowsy even if you force yourself to stay awake.”

Professor Emery Brown, a co-author, said:

“The TRN is rich in synapses — connections in the brain — that release the inhibitory neurotransmitter GABA.
Therefore, the TRN is almost certainly a site of action of many anesthetic drugs, given that a large classes of them act at these synapses and produce slow waves as one of their characteristic features.”

The study was published in the journal eLife (Lewis et al., 2015).

Brain image from Shutterstock

The Natural Response That Psychopaths Tend To Lack

The connection between psychopathy and contagious yawning.

Psychopaths display less empathy, which is why they are less prone to this normal behaviour.

People with psychopathic tendencies are less prone to ‘contagious yawning’, a new study finds.

Yawning after seeing someone else yawn is linked to empathy and bonding.

But psychopaths are selfish, manipulative, fearless, domineering and, critically, lack empathy.

Mr Brian Rundle, the study’s first author, said:

“You may yawn, even if you don’t have to.
We all know it and always wonder why.
I thought, ‘If it’s true that yawning is related to empathy, I’ll bet that psychopaths yawn a lot less.’
So I put it to the test.”

The study found that people with psychopathic tendencies were less likely to yawn when they saw someone else yawning.

Mr Rundle said:

“The take-home lesson is not that if you yawn and someone else doesn’t, the other person is a psychopath.
A lot of people didn’t yawn, and we know that we’re not very likely to yawn in response to a stranger we don’t have empathetic connections with.
But what we found tells us there is a neurological connection — some overlap — between psychopathy and contagious yawning.
This is a good starting point to ask more questions.”

The study was published in the journal Personality and Individual Differences (Rundle et al., 2015).

Yawn image from Shutterstock

People Sleep Better With Access To This Healing Resource

Lack of sleep linked to poor thinking skills, worse mental health and even obesity.

Lack of sleep linked to poor thinking skills, worse mental health and even obesity.

Many people sleep better when they have access to nature, a new study finds.

It could be an ocean view, a green space nearby or any natural surroundings.

People over-65 and men of all ages slept better when they had access to nature, the research found.

Professor Diana Grigsby-Toussaint, the study’s first author, said:

“It’s hard to overestimate the importance of high-quality sleep.
Studies show that inadequate sleep is associated with declines in mental and physical health, reduced cognitive function, and increased obesity.
This new study shows that exposure to a natural environment may help people get the sleep they need.”

Data from 255,171 people was included in the research.

It asked about the number of days of insufficient sleep and access to green space.

Across all the age-groups it was men that seemed to benefit more from natural spaces.

It may be that women use natural public spaces less because of safety concerns.

For over-65s, though, the sleep of both men and women benefited from access to nature.

Professor Grigsby-Toussaint said:

“If there is a way for persons over 65 to spend time in nature, it would improve the quality of their sleep–and their quality of life–if they did so.

…our results provide an incentive for nursing homes and communities with many retired residents to design buildings with more lighting, create nature trails and dedicated garden spaces, and provide safe outdoor areas that encourage outdoor activity for men and women.”

The research was published in the journal Preventive Medicine (Grigsby-Toussaint et al., 2015).

No sleep image from Shutterstock

How a Jet-Set Lifestyle Could Affect Mental Health

The effect of frequent, long-distance travel on mental health.

The effect of frequent, long-distance travel on mental health.

Frequent, long-distance travel has been linked to high levels of stress and loneliness by new research.

This dark side to travel is in stark contrast to the way it is frequently represented by the media.

Dr Scott Cohen, the study’s lead author, said:

“A man in a sharp suit, reclining in a leather chair, laptop open in front of him, a smiley stewardess serving a scotch and soda.
This is often the image of travel, particularly business travel portrayed in TV ads and glossy magazines.
But there is a dark side to this ‘glamorised’ hypermobile lifestyle that the media, and society ignores.”

The research concluded that jet-setters were more likely to suffer health problems like deep vein thrombosis and radiation exposure.

However, there is little discussion of this darker side.

Dr Cohen said:

“The level of physiological, physical and societal stress that frequent travels places upon individuals has potentially serious and long-term negative effects that range from the breaking down of family relationships, to changes in our genes due to lack of sleep.
It is not only traditional media that perpetuates this image.
Social media encourages competition between travellers to ‘check-in’ and share content from far-flung destinations.
The reality is that most people who are required to engage in frequent travel suffer high levels of stress, loneliness and long-term health problems.
There are also wider implications for the environment and sustainability.
In this context, hypermobility seems far from glamourous.”

Dr Cohen concluded:

“Society needs to recognise that the jet-set lifestyle is not all it’s made out to be.
By striving to travel far, wide and frequently we are damaging the environment, ourselves and potentially our closest loved ones.”

The study was published in the journal Environment and Planning A (Cohen & Gössling, 2015).

Jetset image from Shutterstock

Sleep Does More For Memory Than Just Preserve It, Study Finds

Sleep does more for memory than just protect it against forgetting.

Sleep does more for memory than just protect it against forgetting.

Sleep can double the chance of recalling a forgotten memory, a new study finds.

It may do this by enhancing memories and making them more vivid and accessible.

The boost is in addition to sleep’s well-known ability to protect against forgetting.

For the research people’s memory for made-up words was tested before and after sleep.

The effects of sleep were compared to when people were simply awake for a period.

The study found that sleep did more than just preserve memory.

Sleep actually helped people recall words that previously they could not remember.

Dr Nicolas Dumay, the study’s author, said:

“Sleep almost doubles our chances of remembering previously unrecalled material.
The post-sleep boost in memory accessibility may indicate that some memories are sharpened overnight.
This supports the notion that, while asleep, we actively rehearse information flagged as important.
More research is needed into the functional significance of this rehearsal and whether, for instance, it allows memories to be accessible in a wider range of contexts, hence making them more useful.”

The boost to memory could be down to activity in the hippocampus, Dr Dumay thinks.

It’s in this region of the brain that recently laid down memories may be ‘unzipped’ and ‘replayed’.

It could be this process that helps us remember things we couldn’t before.

The research was published in the journal Cortex (Dumay, 2015).

Sleep waves image from Shutterstock

The Good Habit Which Boosts Self-Control

This good habit can boost attention, decision-making and the ability to resist impulses.

This good habit can boost attention, decision-making and the ability to resist impulses.

Good sleep habits can boost attention, decision-making and the ability to resist impulses, a new review of the evidence finds.

Good sleep habits include going to bed at the same time every night, avoiding caffeine late in the day and allowing time to mentally wind-down before bedtime.

Professor June Pilcher, who led the study, said:

“Self-control is part of daily decision-making.
When presented with conflicting desires and opportunities, self-control allows one to maintain control.
Our study explored how sleep habits and self-control are interwoven and how sleep habits and self-control may work together to affect a person’s daily functioning.”

Professor Pilcher explained the review’s conclusions:

“Poor sleep habits, which include inconsistent sleep times and not enough hours of sleep, can also lead to health problems, including weight gain, hypertension and illness, according to prior research.
Studies have also found that sleep deprivation decreases self-control but increases hostility in people, which can create problems in the workplace and at home.”

Since sleep and self-control are so intimately connected, improving sleep can help in many ways, Professor Pilcher said:

“Many aspects of our daily lives can be affected by better-managed sleep and self-control capacity.
Improved health and worker performance are two potential benefits, but societal issues such as addictions, excessive gambling and over spending could also be more controllable when sleep deficiencies aren’t interfering with one’s decision making.”

The study was published in the journal Frontiers in Human Neuroscience (Pilcher et al., 2015).

Self-control image from Shutterstock