Sleep Deprivation
Sleep deprivation is a common problem in the United States affecting milllions of all ages. While the consequences of insufficient sleep are well known through first hand experience the scientific causes are not as established. However more details as to why people function less capably are coming to light as studies related to the problem continue. One area of concern has been decreased brain related functions. An article, whose web address follows, describes the link between sleep deprivation and impaired spatial learning.
http://news.biocompare.com/newsstory.asp?id=115859
Spatial learning involves a common experience in life- the ability to memorize how to get to a destination. Some of us are better at this than others but all of us appear to lose memory capacity when deprived of sleep. As stated in the article, "learning spatial tasks increases the production of new cells in an area of the brain involved with spatial memory called the hippocampus. Sleep plays a part in helping those new brain cells survive. A team of researchers from the University of California and Stanford University found that sleep-restricted rats had a harder time remembering a path through a maze compared to their rested counterparts. And unlike the rats that got enough sleep, the sleep-restricted rats showed reduced survival rate of new hippocampus cells."1 The hippocampus is a part of the brain involved in both memory function and spatial activity.
Health benefits of sleep have been underestimated. If you believe lack of sleep equates merely to increased fatigue you hold a commonly held view that is nevertheless wrong. Lack of sleep negatively impacts our ability to learn.
"Sleep-restricted individuals have a shorter attention span, impaired memory, and a longer reaction time. "Sleep is necessary for general health, but it now appears that the brain needs sleep more than any other part of the body," Hairston said. Previous studies have shown that the hippocampus is important for spatial learning. "The hippocampus also has the unique ability to generate new brain cells throughout life, a process called 'neurogenesis,'" Hairston noted. "When animals learn a task that requires the hippocampus, the rate of neurogenesis increases. This suggests that learning itself rejuvenates the brain." 2
Spatial learning has been indicated as causing the production of new brain cells in the hippocampus. Researchers using rats in an experiment concluded that "lack of sleep undoes the cell rejuvenation benefit that would normally come from the task. "3 While spatial learning can be like a work out for the brain, lack of sleep curtails the benefits of that learning within the hippocampus. It could be thought of as similar to a weight lifter who after a beneficial work out does not allow the muscles suffcient time to rest and thereby strengthen themselves due to the exercise.
Researchers had a good news, bad news conclusion based on experimental results. By learning one can increase intellectual capabilities that result from the learning and the physiological effects within the brain induced by learning. It is a strategy that could provide a more effective intellect for the young and stave off brain related aging effects for older people. However as the article points out "not getting enough sleep eliminates the potential benefit of new learning on the hippocampus by suppressing neurogenesis."4
Although sleep deprivation hinders performance it appears to affect separate areas of the brain differently. After having been deprived of sleep researchers have found that some areas of the brain are still very active while others may go into shut down mode.
A more detailed treatment of the subject matter appears in a news release from the UCSD School of Medicine. It cited the use of functional magnetic resonance imaging technology to monitor brain activity specifically referring to the prefrontal cortex, the temporal lobe and the parietal lobes. Brain function was said to vary according to task and a phenomenon known as compensation was referred to in explaining how adverse effects caused by sleep deprivation are coped with. The following comment would be revealing of benefits conferred by proper amount of sleep.
"The researchers speculate that the brain is adversely affected by sleep deprivation because certain patterns of electrical and chemical activity that occur during sleep are interrupted, impeding the brain’s ability to function normally."5
A separate article appearing in WebMD Medical News indicates that abstract thinking dependent tasks may suffer more due to lack of sleep than other tasks. "Sleep deprivation is bad for your brain when you are trying to do high-level [thinking] tasks," study co-author J. Christian Gillin, MD, tells WebMD. "It may have serious consequences both on performance and on the way your brain functions."6
There is still more to learn about the relationship between sleep deprivation and brain function however while there is the expected evidence of sub-par performance there is also evidence that parts of the brain work even more in compensating or as is noted in the article:
"Jim Horne, PhD, director of the sleep research laboratory at Loughborough University in England, notes in a commentary accompanying the study that the part of the brain that overworks in the sleep-deprived people normally is one of the most active areas of the brain. It is involved in complex functions such as updating working memory, planning, attention, sense of time, dealing with novel situations, and verbal fluency. "Some years ago, we suspected that if sleep offers some sort of recovery process, then the parts of the cortex that work hardest during wakefulness may be those that suffer the deprivation initially," he tells WebMD. "But what seems to be happening is that the functional part of the brain appears to be working even harder during compensation -- to no avail, because performance shows deterioration." 7
One of history's great geniuses, Thomas Edison, was fond of taking naps to rejuvenate himself. There now may be scientific data validating his habit. The initial stage of sleep may be more important for the brain than the latter stages. As the article went on to state:
"However, Horne says that this part of the brain gets its rest during the earliest stages of sleep. "Not all of sleep is for recovery. A particular part of sleep occurring in the early part of sleep is most important for [brain] recovery, and the latter part is not so important in that regard," he says. "As we can eat more food than we require and drink more fluids than we require, we may sleep more than we require. Rather than trying to extend one's sleep ? perhaps we should take short naps instead."8
While the effects of lack of sleeep on the brain have been documented and those who have experienced lack of sleep can testify about the fatigue felt the next day, there was a surprising finding coming out of research from the University of Quebec concerning a relationship between insufficient sleep and a tendency for children to be overweight. Surprisingly enough lack of sleep may contribute more to weight gain than physical inactivity brought on by watching too much television or other physically passive activities according to an article appearing in the Science Daily website. According to the article:
"Researchers from the University of Laval in Quebec looked at the lifestyles, habits, body mass index and waist size of 422 children between the ages of 5 and 10. In all, 20 percent of boys and 24 percent of girls in the study were overweight. After analyzing the data, researchers discovered that those children who slept fewer than 10 hours a night were 3.5 times more likely to be overweight than those who slept more than 12 hours a night. Other factors that may contribute to weight gain, including time spent watching television, parental education, family income and regular physical activity, were found to have much lower impact on a child becoming overweight."9
It seems almost counter-intuitive to think that more sleep, the physically least active endeavor, can lead to weight loss but as the following quote from the article explains important regulatory activity may occur during sleep which influences whether or not we feel hungry.
"One possible explanation for the connection between lack of sleep and weight, according to Dr. Jean Philippe Chaput and colleagues, is that, during sleep, the body regulates the levels of certain hormones that make us feel either hungry or satiated. In other words, excess time in bed may help the body stave off hunger pains. "It is somewhat paradoxical that sleeping, the most sedentary of all activities, may be associated with leanness," writes Chaput. "10
References
1. Losing Sleep Undoes The Rejuvenating Effects New Learning Has On The Brain, Biocompare's Life Science News, 1/9/2006, Source: American Physiological Society
http://news.biocompare.com/newsstory.asp?id=115859
2. Losing Sleep Undoes the Rejuvenating Effects New Learning Has on the Brain, Ref. 1
3. Losing Sleep Undoes the Rejuvenating Effects New Learning has on the Brain, Ref. 1
4. Losing Sleep Undoes the Rejuvenating Effects New Learning has on the Brain, Ref. 1
5. Brain Activity is Visibly Altered Following Sleep Deprivation, July 29, 2002, UCSD School of Medicine,
http://health.ucsd.edu/news/2000_02_09_Sleep.html
6. DeNoon, Daniel, Lack of Sleep Takes Toll on Brain Power, WebMD Medical News,
http://www.webmd.com/content/article/21/1728_54980
7. DeNoon, Daniel, Ref. 6
8. DeNoon, Daniel, Ref. 6
9. Barrow, Karen, Less Sleep May Mean More Weight for Kids, Science Daily website,
http://tinyurl.com/zjbbr
10. Barrow, Karen, Ref. 9
http://news.biocompare.com/newsstory.asp?id=115859
Spatial learning involves a common experience in life- the ability to memorize how to get to a destination. Some of us are better at this than others but all of us appear to lose memory capacity when deprived of sleep. As stated in the article, "learning spatial tasks increases the production of new cells in an area of the brain involved with spatial memory called the hippocampus. Sleep plays a part in helping those new brain cells survive. A team of researchers from the University of California and Stanford University found that sleep-restricted rats had a harder time remembering a path through a maze compared to their rested counterparts. And unlike the rats that got enough sleep, the sleep-restricted rats showed reduced survival rate of new hippocampus cells."1 The hippocampus is a part of the brain involved in both memory function and spatial activity.
Health benefits of sleep have been underestimated. If you believe lack of sleep equates merely to increased fatigue you hold a commonly held view that is nevertheless wrong. Lack of sleep negatively impacts our ability to learn.
"Sleep-restricted individuals have a shorter attention span, impaired memory, and a longer reaction time. "Sleep is necessary for general health, but it now appears that the brain needs sleep more than any other part of the body," Hairston said. Previous studies have shown that the hippocampus is important for spatial learning. "The hippocampus also has the unique ability to generate new brain cells throughout life, a process called 'neurogenesis,'" Hairston noted. "When animals learn a task that requires the hippocampus, the rate of neurogenesis increases. This suggests that learning itself rejuvenates the brain." 2
Spatial learning has been indicated as causing the production of new brain cells in the hippocampus. Researchers using rats in an experiment concluded that "lack of sleep undoes the cell rejuvenation benefit that would normally come from the task. "3 While spatial learning can be like a work out for the brain, lack of sleep curtails the benefits of that learning within the hippocampus. It could be thought of as similar to a weight lifter who after a beneficial work out does not allow the muscles suffcient time to rest and thereby strengthen themselves due to the exercise.
Researchers had a good news, bad news conclusion based on experimental results. By learning one can increase intellectual capabilities that result from the learning and the physiological effects within the brain induced by learning. It is a strategy that could provide a more effective intellect for the young and stave off brain related aging effects for older people. However as the article points out "not getting enough sleep eliminates the potential benefit of new learning on the hippocampus by suppressing neurogenesis."4
Although sleep deprivation hinders performance it appears to affect separate areas of the brain differently. After having been deprived of sleep researchers have found that some areas of the brain are still very active while others may go into shut down mode.
A more detailed treatment of the subject matter appears in a news release from the UCSD School of Medicine. It cited the use of functional magnetic resonance imaging technology to monitor brain activity specifically referring to the prefrontal cortex, the temporal lobe and the parietal lobes. Brain function was said to vary according to task and a phenomenon known as compensation was referred to in explaining how adverse effects caused by sleep deprivation are coped with. The following comment would be revealing of benefits conferred by proper amount of sleep.
"The researchers speculate that the brain is adversely affected by sleep deprivation because certain patterns of electrical and chemical activity that occur during sleep are interrupted, impeding the brain’s ability to function normally."5
A separate article appearing in WebMD Medical News indicates that abstract thinking dependent tasks may suffer more due to lack of sleep than other tasks. "Sleep deprivation is bad for your brain when you are trying to do high-level [thinking] tasks," study co-author J. Christian Gillin, MD, tells WebMD. "It may have serious consequences both on performance and on the way your brain functions."6
There is still more to learn about the relationship between sleep deprivation and brain function however while there is the expected evidence of sub-par performance there is also evidence that parts of the brain work even more in compensating or as is noted in the article:
"Jim Horne, PhD, director of the sleep research laboratory at Loughborough University in England, notes in a commentary accompanying the study that the part of the brain that overworks in the sleep-deprived people normally is one of the most active areas of the brain. It is involved in complex functions such as updating working memory, planning, attention, sense of time, dealing with novel situations, and verbal fluency. "Some years ago, we suspected that if sleep offers some sort of recovery process, then the parts of the cortex that work hardest during wakefulness may be those that suffer the deprivation initially," he tells WebMD. "But what seems to be happening is that the functional part of the brain appears to be working even harder during compensation -- to no avail, because performance shows deterioration." 7
One of history's great geniuses, Thomas Edison, was fond of taking naps to rejuvenate himself. There now may be scientific data validating his habit. The initial stage of sleep may be more important for the brain than the latter stages. As the article went on to state:
"However, Horne says that this part of the brain gets its rest during the earliest stages of sleep. "Not all of sleep is for recovery. A particular part of sleep occurring in the early part of sleep is most important for [brain] recovery, and the latter part is not so important in that regard," he says. "As we can eat more food than we require and drink more fluids than we require, we may sleep more than we require. Rather than trying to extend one's sleep ? perhaps we should take short naps instead."8
While the effects of lack of sleeep on the brain have been documented and those who have experienced lack of sleep can testify about the fatigue felt the next day, there was a surprising finding coming out of research from the University of Quebec concerning a relationship between insufficient sleep and a tendency for children to be overweight. Surprisingly enough lack of sleep may contribute more to weight gain than physical inactivity brought on by watching too much television or other physically passive activities according to an article appearing in the Science Daily website. According to the article:
"Researchers from the University of Laval in Quebec looked at the lifestyles, habits, body mass index and waist size of 422 children between the ages of 5 and 10. In all, 20 percent of boys and 24 percent of girls in the study were overweight. After analyzing the data, researchers discovered that those children who slept fewer than 10 hours a night were 3.5 times more likely to be overweight than those who slept more than 12 hours a night. Other factors that may contribute to weight gain, including time spent watching television, parental education, family income and regular physical activity, were found to have much lower impact on a child becoming overweight."9
It seems almost counter-intuitive to think that more sleep, the physically least active endeavor, can lead to weight loss but as the following quote from the article explains important regulatory activity may occur during sleep which influences whether or not we feel hungry.
"One possible explanation for the connection between lack of sleep and weight, according to Dr. Jean Philippe Chaput and colleagues, is that, during sleep, the body regulates the levels of certain hormones that make us feel either hungry or satiated. In other words, excess time in bed may help the body stave off hunger pains. "It is somewhat paradoxical that sleeping, the most sedentary of all activities, may be associated with leanness," writes Chaput. "10
References
1. Losing Sleep Undoes The Rejuvenating Effects New Learning Has On The Brain, Biocompare's Life Science News, 1/9/2006, Source: American Physiological Society
http://news.biocompare.com/newsstory.asp?id=115859
2. Losing Sleep Undoes the Rejuvenating Effects New Learning Has on the Brain, Ref. 1
3. Losing Sleep Undoes the Rejuvenating Effects New Learning has on the Brain, Ref. 1
4. Losing Sleep Undoes the Rejuvenating Effects New Learning has on the Brain, Ref. 1
5. Brain Activity is Visibly Altered Following Sleep Deprivation, July 29, 2002, UCSD School of Medicine,
http://health.ucsd.edu/news/2000_02_09_Sleep.html
6. DeNoon, Daniel, Lack of Sleep Takes Toll on Brain Power, WebMD Medical News,
http://www.webmd.com/content/article/21/1728_54980
7. DeNoon, Daniel, Ref. 6
8. DeNoon, Daniel, Ref. 6
9. Barrow, Karen, Less Sleep May Mean More Weight for Kids, Science Daily website,
http://tinyurl.com/zjbbr
10. Barrow, Karen, Ref. 9
posted by Paul at 7:11 PM
0 comments
