Interests:Group and institutional dynamics; The interplay between our psychology and our spirituality Expertise:Psychology Occupation:MR/RD Service Coordinator Industry:Psychology/Ministry
"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," researcher Matthew Walker, a neuroscientist at the University of California, Berkeley, told LiveScience.
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.
Walker and his colleagues had 26 healthy volunteers either get normal sleep or get sleep deprived, making them stay awake for roughly 35 hours. On the following day, the researchers scanned brain activity in volunteers using functional magnetic resonance imaging (fMRI) while they viewed 100 images. These started off as emotionally neutral, such as photos of spoons or baskets, but they became increasingly negative in tone over time—for instance, pictures of attacking sharks or vipers.
"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."
The researchers pinpointed this hyperactive response to a shutdown of the prefrontal lobe, a brain region that normally keeps emotions under control. This structure is relatively new in human evolution, "and so it may not yet have adapted ways to cope with certain biological extremes," Walker speculated. "Human beings are one of the few species that really deprive themselves of sleep. It's a real oddity in nature."
In modern life, people often deprive themselves of sleep "almost on a daily basis," Walker said. "Alarm bells should be ringing about that behavior—no pun intended."
Future research can focus on which components of sleep help restore emotional stability—"whether it's dreaming REM sleep or slow-wave, non-dreaming forms of sleep," Walker said.
Many psychiatric disorders, "particularly ones involving emotions, seem to be linked with abnormal sleep," he added. "Traditionally people mostly thought the psychiatric disorders were contributing to the sleep abnormalities, but of course it could be the other way around. If we can find out which parts of sleep are most key to emotional stability, we already have a good range of drugs that can push and pull at these kinds of sleep and maybe help treat certain kinds of psychiatric conditions."
LONDON (Reuters) - People who do not get enough sleep are more than twice as likely to die of heart disease, according to a large British study released on Monday.
Although the reasons are unclear, researchers said lack of sleep appeared to be linked to increased blood pressure, which is known to raise the risk of heart attacks and stroke.
A 17-year analysis of 10,000 government workers showed those who cut their sleeping from seven hours a night to five or less faced a 1.7-fold increased risk in mortality from all causes and more than double the risk of cardiovascular death.
The findings highlight a danger in busy modern lifestyles, Francesco Cappuccio, professor of cardiovascular medicine at the University of Warwick's medical school, told the annual conference of the British Sleep Society in Cambridge.
"A third of the population of the UK and over 40 percent in the U.S. regularly sleep less than five hours a night, so it is not a trivial problem," he said in a telephone interview.
"The current pressures in society to cut out sleep, in order to squeeze in more, may not be a good idea -- particularly if you go below five hours."
Previous research has highlighted the potential health risks of shift work and disrupted sleep. But the study by Cappuccio and colleagues, which was supported by British government and U.S. funding, is the first to link duration of sleep and mortality rates.
The study looked at sleep patterns of participants aged 35-55 years at two points in their lives -- 1985-88 and 1992-93 -- and then tracked their mortality rates until 2004.
The results were adjusted to take account of other possible risk factors such as initial age, sex, smoking and alcohol consumption, body mass index, blood pressure and cholesterol.
The correlation with cardiovascular risk in those who slept less in the 1990s than in the 1980s was clear but, curiously, there was also a higher mortality rate in people who increased their sleeping to more than nine hours.
In this case, however, there was no cardiovascular link and Cappuccio said it was possible that longer sleeping could be related to other health problems such as depression or cancer-related fatigue.
"In terms of prevention, our findings indicate that consistently sleeping around seven hours per night is optimal for health," he said.
I am leaving for Chicago on October 4th to visit Wheaton College. I will be staying with a friend of mine at TIU. Should be a gay ol' time. Also, I am teaching for the High School youth at Apostles. In other news, I hate my job and I am getting married in December. There is my update!
