Showing posts with label sleepy. Show all posts
Showing posts with label sleepy. Show all posts

Tuesday, March 12, 2013

Sleep Improves Children’s Ability to Absorb Information and Learn

By Matthew D. Mingrone, M.D. of eOs Sleep

It has been common scientific knowledge for some time that when people sleep, our brains consolidate the information we subconsciously absorb during the day, and process it into explicit, conscious knowledge.

Both children and adults do this, but an interesting new study out of Germany shows that during sleep, children's brains convert subconsciously absorbed information—known as implicit learning—into active, useful knowledge even more effectively than adult brains do.
Implicit learning is typically considered subconscious learning; the acquisition of knowledge independent of conscious attempts to learn. For example, a child can say a sentence without understanding the rules of English grammar.

Explicit learning, on the other hand, is deliberate, conscious learning; the active and aware acquisition of skills and/or knowledge. Typically, explicit learning is accompanied by “meta-awareness,” a person can explain how they acquired the skill and/or knowledge.
When we sleep, implicit knowledge becomes explicit memory, making it easier for us to recall and use the information we have previously absorbed.

In a new study conducted by Dr. Ines Wilhelm of the University of Tübingen's Institute for Medical Psychology and Behavioral Neurobiology in Germany, and colleagues, the researchers studied 35 children between the ages of 8 and 11 years old, as well as 37 adults between 18 and 35.

For the test, the subjects were asked to press a sequence of buttons after they lit up. Half of the subjects did the test before sleep, the other half after sleep. They were then asked to recall the sequence of buttons/lights 10 to 12 hours later. Following a night of sleep or a day awake, the subjects’ memories were tested.

An article explaining the results of the study, entitled, “The sleeping child outplays the adult's capacity to convert implicit into explicit knowledge,” is published in the February 24, 2013 online edition of Nature Neuroscience.

The authors observed that after a night’s sleep, both age groups—8 to 11 and 18 to 35—remembered a larger sequence of buttons/lights than those who did not sleep. It also showed the children were better at it than the adults—almost all of the children could remember the sequence they had pressed perfectly, while adults experienced smaller gains.

Lead author Dr. Ines Wilhelm wrote, “In children, much more efficient explicit knowledge is generated during sleep from a previously learned implicit task. And the children’s extraordinary ability is linked with the large amount of deep sleep they get at night. The formation of explicit knowledge appears to be a very specific ability of childhood sleep, since children typically benefit as much or less than adults from sleep when it comes to other types of memory tasks.”

Children absorb massive amounts of information every day. They also generally sleep longer and deeper, and experience three times more slow-wave sleep and higher electrical activity in the brain during sleep than adults. This may help them “convert” the information they take in every day into knowledge they can recall and use. This is yet another important reason why parents should ensure their children are getting enough uninterrupted sleep every night.

Friday, December 21, 2012

Can more sleep help ease pain? Yes, says new study!

Chalk another one up for the benefits of sleep. Researchers at the Sleep Disorders and Research Center at the Henry Ford Hospital in Detroit have found that getting more sleep improves daytime alertness and reduces pain sensitivity in healthy adults.

The study was led by Timothy A. Roehrs, Ph.D. of the Sleep Disorders and Research Center at the Henry Ford Hospital and supported by the Fund for Henry Ford Health System. Roehrs and his colleagues studied 18 pain-free, but mildly sleepy volunteers.

For the study, the participants were randomly assigned to four nights of either their normal amount of sleep, or extending their sleep time to 10 hours in bed per night. Their daytime sleepiness was measured on days one and four using the Multiple Sleep Latency Test (MSLT), a tool that measures how quickly a person falls asleep. Their pain sensitivity was also measured using finger withdrawal latency pain testing to a radiant heat stimulus.

The first study to prove sleep reduces pain.

The results of the study were published in the Dec. 1 issue of the journal Sleep. It is the first research of its kind to prove that extended sleep in mildly sleep-deprived adults can significantly reduce their sensitivity to pain.

The results showed that the extended sleep group—those who slept more than normal—slept 1.8 hours more per night than the normal sleep group. It also showed that they experienced less daytime sleepiness. This increase in sleep time during the four nights correlated to increased daytime alertness, as well as less sensitivity to pain.

Regarding the pain test, the extended sleep group showed a greater tolerance for pain/reduced pain sensitivity. The length of time before participants removed their finger from a radiant heat source increased by 25 percent. The researchers noted that this increase in “finger withdrawal latency” is greater than the effect found in a previous study where participants used 60 milligrams of codeine.

In their report, the researchers stated that the results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.

Timothy Roehrs, PhD, the study’s principal investigator and lead author said, “The results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures. We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine.”
Read the press release for the study, “Extended sleep reduces pain sensitivity.”

Lack of sleep and an increase in strokes.

Roehrs’ study adds to growing evidence that more regular, restorative sleep can help reduce the risk of health problems, and the opposite is true, as well.

Last June, the University of Alabama at Birmingham released the results of a study that regularly sleeping less than six hours a night significantly increases the risk of stroke symptoms in middle-age to older adults who are of normal weight and at low risk for obstructive sleep apnea (OSA). That’s worth repeating: Less than six hours of sleep per night increases the risk of strokes in adults of normal weight and not at risk for OSA.
It seems that under six hours of sleep per night is the critical variable, but why? Let’s take a look at the study. The University of Alabama researchers followed 5,666 people  for up to three years who had no history of strokes or stroke-like symptoms, transient ischemic attacks (when blood flow to the brain stops for a brief period causing stroke-like symptoms), or high risk for OSA at the start of the study.

For a period of three years, the researchers followed and studied the subjects’ first stroke symptoms, stroke risk factors, depression symptoms, demographic information and other various health behaviors. What they found was—after adjusting for body-mass index (BMI)—there was a strong association between daily sleep periods of less than six hours and a greater incidence of stroke symptoms for middle-age to older adults, even beyond other risk factors. Interestingly, the researchers did not find any link between short sleep periods and stroke symptoms in overweight and obese participants.

Still, the connection between short sleep and strokes is worthy of great attention from the medical community and general public. I agree with the Alabama study’s lead author, Megan Ruiter, PhD., who said, “The results of the Alabama study provide a strong argument for increasing physician and public awareness of the impact of sleep as a risk factor for stroke symptoms, especially among persons who appear to have few or no traditional risk factors for stroke.”

It looks like the medical community is taking this message to heart, no pun intended. Another study announced in late July is going on at the Alberta Health Services and the University of Calgary. There, Dr. Patrick Hanly of the university’s Hotchkiss Brain Institute is leading a study to learn more about the physiological connection between sleep apnea and stroke—specifically, the brain’s blood flow response in people with and without sleep apnea.

For the study, participants with sleep apnea stay overnight in the sleep laboratory at Calgary’s Foothills Medical Centre, where their breathing and cardiovascular responses are continuously monitored while they sleep. The next day, their brain blood flow response to reduced oxygen levels is assessed while they are awake. Then, the participants receive supplemental oxygen during sleep for two weeks, and are tested again to see if their cerebral defense mechanisms have improved. The researchers are also studying people without sleep apnea to see if their cerebral defense mechanisms function better than in those with sleep apnea. Hanly and team’s theory is that it is the lack of oxygen, or hypoxia, that people with sleep apnea experience during sleep that impairs the body’s normal defense mechanisms in the brain. A better understanding of this connection will lead to better prevention and treatment strategies.

I applaud the work of the Alabama and Calgary researchers. It’s time we all wake up to the health benefits of regular, restorative sleep

For more information, read the University of Alabama at Birmingham study, “Under 6 Hours of Sleep Tops Risks for Stroke in a Low-risk Population.”