Psychologist Matthew Walker of the University of California, Berkeley, says that “almost all psychiatric disorders show some problems with sleep.'’ But, he says that scientists previously believed the psychiatric problems triggered the sleep issues. New research from his lab, however, suggests the reverse is the case; that is, a lack of shut-eye is causing some psychological disturbances. (…)

“There seems to be a causal relationship between impaired sleep and some of the psychiatric symptomatology and disorders that we’re seeing,” says Robert Stickgold, an associate professor of psychiatry at Harvard Medical School who was not involved in this study. He cites research linking sleep apnea, in which breathing is disrupted, to attention deficit hyperactivity disorder and the evidence of a connection between depression and insomnia as examples. “It might be that those medial frontal regions tell the rest of the brain, ‘You can chill,’” he says. “Those circuits become exhausted or altered after a lack of sleep.”

“I think we may start to think about a new potential function for sleep,” says Walker. “It does actually prepare our emotional brains for next-day social and emotional interactions.”

{ Scientific American | Continue reading }

photo { Brad Miller, Strange Girls | interview }

Without sleep, the emotional centers of our brains dramatically overreact to bad experiences, research now reveals.

“When we’re sleep deprived, it’s really as if the brain is reverting to more primitive behavior, regressing in terms of the control humans normally have over their emotions,” said researcher Matthew Walker, a neuroscientist at the University of California, Berkeley.

Anyone who has ever gone without a good night’s sleep is aware that doing so can make a person emotionally irrational. While past studies have revealed that sleep loss can impair the immune system and brain processes such as learning and memory, there has been surprisingly little research into why sleep deprivation affects emotions, Walker said.

“While we predicted that the emotional centers of the brain would overreact after sleep deprivation, we didn’t predict they’d overreact as much as they did,” Walker said. “They became more than 60 percent more reactive to negative emotional stimuli. That’s a whopping increase—the emotional parts of the brain just seem to run amok.”

{ LiveScience | Continue reading }

Fish might not have eyelids, but they do sleep, and some suffer from insomnia, scientists reported today.

California scientists studying sleep disorders in humans found some zebrafish, a common aquarium pet, have a mutant gene that disrupts their sleep patterns in a way similar to insomnia in humans.

Zebrafish with the mutant gene slept 30 per cent less than fish without the mutation. When they finally drifted off, they remained asleep half as long as the normal fish, the researchers at the Stanford University School of Medicine said.

{ Herald Sun | Continue reading }

About three years ago Eva Salem got into some trouble with a crocodile. It snapped her hand in its jaws. In a panic, she managed to knock out the crocodile and free herself. Then, she woke up.

“I imagine that’s what it’s like when you’re on heroin. That’s what my dreams were like—vivid, crazy and active,” she says. Salem, a new mother, had been breast-feeding her daughter for five months before the croc-attack dream, living on four hours of sleep a night. If she did sleep a full night, her dreams boomeranged, becoming so vivid that she felt like she wasn’t sleeping at all.

Dreams are amazingly persistent. Miss a few from lack of sleep and the brain keeps score, forcing payback soon after eyelids close. “Nature’s soft nurse,” as Shakespeare called sleep, isn’t so soft after all.

“When someone is sleep deprived we see greater sleep intensity, meaning greater brain activity during sleep; dreaming is definitely increased and likely more vivid,” says neurologist Mark Mahowald of the University of Minnesota and director of the Minnesota Regional Sleep Disorders Center in Minneapolis.

The phenomenon is called REM rebound. REM refers to “rapid eye movement,” the darting of the eyes under closed lids. In this state we dream the most and our brain activity eerily resembles that of waking life. Yet, at the same time, our muscles go slack and we lie paralyzed—a toe might wiggle, but essentially we can’t move, as if our brain is protecting our bodies from acting out the stories we dream.

Sleep is divided into REM and four stages of non-REM; each has a distinct brain wave frequency. Stage one of non-REM is the nodding off period where one is between sleeping and waking; it’s sometimes punctuated with a sensation of falling into a hole. In stage two the brain slows with only a few bursts of activity. Then the brain practically shuts off in stages three and four and shifts into slow-wave sleep, where heart and breathing rates drop dramatically.

Only after 70 minutes of non-REM sleep do we experience our first period of REM, and it lasts only five minutes. A total non-REM–REM cycle is 90 minutes; this pattern repeats about five times over the course of a night. As the night progresses, however, non-REM stages shorten and the REM periods grow, giving us a 40-minute dreamscape just before waking.

{ Scientific American | Continue reading }

photo { skatemoss }

Researchers from the University of Warwick, and University College London, have found that lack of sleep can more than double the risk of death from cardiovascular disease. However they have also found that point comes when too much sleep can also more than double the risk of death. (…)

Amongst other things the data they used provided information on the mortality rates and sleep patterns on 10,308 civil servants at two points in their life (1985-8 and those still alive in 1992-3). (…)

Those who had cut their sleeping from 7h to 5 hours or less faced a 1.7 fold increased risk in mortality from all causes, and twice the increased risk of death from a cardiovascular problem in particular.

Fewer hours sleep and greater levels of sleep disturbance have become widespread in industrialised societies. This change, largely the result of sleep curtailment to create more time for leisure and shift-work, has meant that reports of fatigue, tiredness and excessive daytime sleepiness are more common than a few decades ago. Sleep represents the daily process of physiological restitution and recovery, and lack of sleep has far-reaching effects.

Curiously the researchers also found that too much sleep also increased mortality. They found that those individuals who showed an increase in sleep duration to 8 hours or more a night were more than twice as likely to die as those who had not changed their habit, however, predominantly from non-cardiovascular diseases.

{ Yuba | Continue reading }

Every day after lunch, you find yourself overcome by drowsiness, and you can’t get any work done because you just want to crawl under your desk and go to sleep. What is happening in the body that it craves rest after lunch?
First, the 24-hour cycle of the body, or its circadian rhythm, is naturally in a resting phase at this time. It is entirely natural for humans to want to go to sleep about seven hours after they have awakened. In the afternoon, it happens to converge with another physiological cycle — known as homeostatic — that measures the amount of time spent awake and that is also pushing for a rest. Add the effects of food, which can also induce drowsiness, and an overpowering desire to sleep may result.

Do all people experience the post-lunch dip?
The effect may be natural, but “not everyone experiences it with equal intensity,” said David F. Dinges, a professor and sleep scientist at the University of Pennsylvania School of Medicine. A few people say they don’t feel the dip at all, while others — about 15 percent to 20 percent of the population, he estimates — are “closet nappers.” These are the ones who steal into empty rooms or their parked cars, or fall asleep at their desks, because they can’t fight off the urge to close their eyes.

{ NY Times | Continue reading }

photo { Bert Stern, Marilyn Monroe, 1962 }

related { Tired and strained eyes? You’re looking at the wrong part of your computer monitor. }

A study completed this spring by Washington State University Spokane suggests that our sleep patterns are embedded in our bodies - perhaps in our very genes. It’s a conclusion that challenges previous assumptions in sleep research.

“Always, since the beginning of sleep research, it’s been assumed that individual differences in sleep were due to circumstance,” said Tucker, the lead author of a report on the study. Such circumstances could include consistently going to bed late and getting up early, or trying to sleep in noisy conditions, or choosing a certain type of bed.

Tucker said the WSU study shows that habits and choices play a role in sleep patterns, but that differences are biologically driven.

“For the average person, that means there’s only a limited amount of control you will have over changing your sleep,” Tucker said. So much for those soothing cups of chamomile tea. (…)

Researchers logged data about 18 types of sleep parameters, including how long people slept, how long it took them to fall asleep and the amounts of time spent in the various stages of sleep. For most categories, researchers found that biology accounted for about half of the differences observed. But in the deeper, most restorative stages of sleep, biology appeared to influence sleep behaviors almost entirely.

{ The Columbian | Continue reading }

Viagra used in combination with light aid jetlag recovery, animal research suggests.

A team of Argentine scientists found the drug helped hamsters recover up to 50% faster from forward shifts in their daily time cycles. However, the drug only worked in conjunction with light therapy, and only in one time direction - the equivalent to flying eastbound.

In mammals, the light-dark cycle regulates the body’s biological clock, which promotes activity during the daytime, when it is light, and sleep at night.

The researchers from the National University of Quilmes shifted the light-dark cycle of hamsters six hours forwards, by switching on lights six hours earlier than usual. They then monitored the hamsters’ running wheel activity to assess when their body clocks had adjusted to the new time cycle - the hamsters are active in the day but stop running when the lights go out.

Injection of Viagra before the time shift meant the hamsters adjusted to the new time cycle faster, even when low doses of the drug, which did not cause penile erections, were used. When used without the shifts in light, the drug did not induce changes in the hamsters’ activity, so it seems to work by enhancing the light-induced response. { BBC | Continue reading }

image { Thanks Buzzman }

24 hours not enough? Get ready for the 25-hour day. A new study, funded by NASA, shows that it’s possible to cram an extra hour into the day. Researchers studied 12 healthy young adults (average age: 28) who volunteered to spend 65 days living in individual rooms without windows, clocks, or any other time cues.

Before the experiment began, the volunteers got eight hours of nightly sleep at home for at least three weeks. When they reported to the lab, they spent three days on a normal 24-hour day. Then the researchers tweaked the hours of light and darkness to pinpoint the participants’ natural circadian rhythm, commonly called the “body clock.” Next, the scientists tacked on an extra hour of light to each participants’ natural amount of daily wakefulness. (…) Participants stayed on the 25-hour-day cycle for a month. They adjusted to the schedule, judging by their core body temperature and levels of melatonin, a hormone involved in circadian rhythms.

The findings may come in handy if astronauts go to Mars. A Martian day lasts for 24.65 earthly hours, note the researchers. They argue that without resetting the body clock to a 25-hour day, astronauts on Mars would be constantly jetlagged, which could be dangerous. { CBS | Continue reading }

photo-montage { Adrian Price }

A new discovery could make it possible to take a “power nap” at the flick of a switch. Scientists have found a way to turn on deep sleep at will using a machine that magnetically stimulates the brain. A device worn on the head could in squeeze the benefit of eight hours’ sleep into just two or three hours.

Scientists in the US used a technique called transcranial magnetic stimulation (TMS) to induce slow waves - indicative of the deepest phase of sleep and essential for learning ability and mood, in a group of sleeping volunteers.

A TMS device sends harmless magnetic signals through the scalp and skull and into the brain, where it activates electrical impulses. The researchers found that positioning the TMS machine the right way triggered slow waves that travelled throughout the brain. Slow wave activity occupies 80% of sleeping hours.

During slow wave sleep, waves of electrical impulses wash across the brain at a rate of roughly one a second. With each magnetic pulse, the volunteers’ brains immediately generated slow waves typical of deep sleep.

“Creating slow waves on demand could some day lead to treatments for insomnia,” said study leader Prof Giulio Tononi, from the University of Wisconsin-Madison. “Theoretically, it could also lead to a magnetically stimulated `power nap’ which might confer the benefit of eight hours’ sleep in just a few hours.” { Sky News | Continue reading }

An early-morning German bank customer had a bit of a shock when he found a horse already in line at the automatic teller machine in front of him. It seems the horse’s owner, identified only as Wolfgang H., had a bit too much to drink the night before and decided to sleep it off inside the bank’s heated foyer, police said Tuesday. { WTOP | Continue reading }

+ { A woman is accused of hiding 27 horses }

Researchers categorized each patient as a morning or evening person, or an intermediate case, depending on when they went to bed and the time of day they preferred to do things. Compared with the morning and intermediate types, night owls went to bed an hour or more later but reported more time spent sleeping and more time in bed. On average, they slept 6.4 hours, compared to 5.9 for early risers, and spent 8.7 hours in bed compared to 7.9.

“Even after we adjusted for the severity of their insomnia [the amount of time they spent awake in bed], there were still differences between the night owls and the morning people,” says Jason Ong, a behavioral sleep psychologist at Stanford University, and lead author of a report published this week in the Journal of Clinical Sleep Medicine. For one thing, night owls were less consistent in when they went to bed and got up.

In addition, “they seemed to hold more negative and more rigid beliefs about what their sleep should be,” Ong says. They reported feeling less in control of their sleep and feeling that they have a hard time getting through the day with less sleep, which might perpetuate insomnia, the researchers say. And the night owls had more risk factors for depression. { Scientific American | Continue reading }

artwork { Roy Lichtenstein, Sleeping Girl, 1964 }