The Body And Sleep
The Body And Sleep
Chris Idzikowski (Director of the Edinburgh Sleep Centre) gives expert video advice on: What happens to my brain when I sleep?; What happens to my muscles when i sleep?; What happens to my breathing when I sleep? and more...
What happens to my brain when I sleep?
What happens to the brain when you go to sleep. It is really complicated. When the brain is in rapid eyeball movement to dreaming sleep, a lot of it is acting in the same way as it is during wakefulness. It is really hard to say. Ten years ago, so we're talking about mid-nineties, we would say it is rather like the brain shuts down, rather like putting a night-cap on the head, the brainwaves become much slower and eventuallly the whole brain is generating this big, large and slow waves. Now we know that is not true. There's just a lot of stuff going on.
What happens to my muscles when i sleep?
When you first go to sleep, your muscles may twitch. Invariably they do--one may or may not be aware of it. It's a kind of disconnection of the system that keeps muscle tone going. Then, as one goes into deep sleep, the muscle tone goes down even more. During Rapid Eye Movement in dreaming sleep, you get active paralysis. If that didn't happen, you'd start to act out your dreams.
What happens to my breathing when I sleep?
With breathing, because one is using less oxygen, breathing rates tends to slow down. That's not necessarily true during Rapid Eye Movement dreaming sleep. During that stage the brain is again quite active and in many ways emotionally not as well controlled as it usually is, so one tends to get extremes in those behaviors that are normally automatically controlled, so breathing can become shallow and irregular.
What happens to my heart when sleep?
The heart rate will go down initially and continue going down into deep sleep. But again, during rapid eye movement dreaming sleep, an emotionally excited time of the brain, it can become much more rapid and irregular.
What are the effects on my body due to the lack of sleep?
The effects on the body due to lack of sleep are marginal at best when lots of sleep is missed it's different. Lots of people, when they become sleep deprived, ethically or even unethically for a long time, end up falling asleep. When one's looking at animal experiments, and there one finds ten to twelve days into sleep deprivation the rats will die. If you selectively deprive them of a particular stage they will take longer to die. The curious thing is that we're not absolutely sure of what the cause of death is. The animals lose control of their body temperature and their body temperature starts to go down. Or it could be a general septic reaction within the body to not being able to rest properly. There is this problem of distinguishing between lack of sleep and lack of rest. In some ways, I almost can't answer the question. It's not good for one, not getting enough sleep, but the precise reason why - we're not entirely sure.
What is atonia?
Atonia is a lack of muscle tone. The phrase muscle atonia during rapid eye movement sleep means that the muscles are paralyzed during rapid eye movement sleep. And it's a real paralysis. The brain's activity centers, movement centers, are trying to get to do things but there's a center low down in the brain that's actively blocking those signals and the antonia results.
Does atonia affect everyone?
Everybody during rapid eye movements sleep has muscle atonia. There is one condition called rapid eye movement behaviour disorder which can be found in its own right or in Parkinson's patients, where the center isn't operating and at that point people are acting out their dreams.
How do brainwaves differ in a sleeping state than when we are awake?
How we describe sleeping waves from us using brainwaves is complicated. But when brainwaves were first discovered, by a chap called Hans Berger, he immediately identified and classified some of the frequencies that could be seen. So, if you put electrodes onto somebody and get them to close their eyes and they are relaxed, then generally they will produce what is called alpha rhythm and that is 8 to 12 cycles per second activity. Not particularly high voltage, very, very obvious, for the most part. When one is in deep sleep one has a situation where one is getting roughly a quarter through to two cycles per second activity; very high voltage is being produced and if you just compare those to alpha sleep and delta sleep, the slow wave sleep, then you can say well that is the big difference between the two. In fact, there are all kinds of shades in between that make it more complicated but, for the most part, alpha sleep is defined by the frequency, delta sleep by the frequency, there is also theta sleep. Theta is a bit faster than delta, there is also beta sleep which is faster than theta. So the slowest frequency is delta, then theta, then alpha, then beta.
Why do we move about in our sleep?
It's a hard question to answer because there's an element of how big of a movement should there be before you classify it as a movement. There's certainly been a lot of work done on moving but we've no real idea, the main thing is probably a lack of comfort.
Why do I wake if I hear a noise?
We don't necessarily awaken when we hear a noise. The lower level senses will work out whether there is a need to awaken. So if it's an alarm or a really odd sound then the brain will start to wake itself up. Not so true in deep sleep, it's much harder to arouse the brain at that point. It's also quite difficult in dreaming sleep, because the sound can get incorporated into the dream as well. But it's a low level sort of response to, well, what's this about? And if it's a question that can't be answered then the rest of the brain is brought in to work it out.
Why is the best way to wake someone from a deep sleep?
The best way to awaken somebody is really just to call out their name, do that sort of quietly and repeatedly.
Why do some people twitch in their sleep?
Everybody has some degree of twitching during sleep. It's not particularly clear why, possibly because movement isn't coordinated in any sense. And some parts of the brain decide to fire off volumes, some muscles twitch.
What ailments are associated with lack of sleep?
There are very few physical effects from lack of sleep. If somebody is having problems with sleeping I always tell them to rest because virtually everything physical will sort itself out during rest. One comment that's been made in the past is that sleep is for the brain, it's mainly for the brain to recover one way or the other. So it's a separation between physical and what the brain needs mentally. If somebody has a lot of problems with sleep, like a <a href="http://www.videojug.com/interview/sleep-disorders-3">sleep disorder</a>, and is thus visiting their general practitioner a lot, then they're very much more likely, subsequent in the future, to develop depression or a mental disorder, so there's an indication of there things possibly going wrong. The other thing that can go wrong with not getting enough sleep, and it's just something that we've become aware of in the last couple of years, is that if people chronically restrict themselves of sleep it may have an impact on their appetite control hormones and the current obesity epidemic may be associated with getting less sleep as well. So although it's not a direct physical effect, we end up being up and around more and our appetite not being controlled means that we eat a lot more and end up putting on more weight.
What is the affect of napping on the body?
Generally can be quite beneficial and one of the things, one of the mysteries about sleep is we don't know what causes us to feel refreshed after sleeping. Good nappers, people who can take a ten, fifteen minute nap, can feel as refreshed after that nap as they can do after nighttime sleep. So we don't know what's going on there. I'd have the general rule of thumb of small amounts of sleep will invariably help mental performance and would say any sleep anytime is worth while getting. Where I wouldn't say that is if somebody has <a href="http://www.videojug.com/interview/hypersomnia-2">hypersomnia</a> or is having problems with nighttime sleep and they were trying to improve their night time sleep. Then what one would do is avoid the daytime sleep to try to increase the pressure for sleep that following night.