A night of sleep can make memories resistant to interference from other information and allow you to recall them more effectively. It also lets your brain sift through newly formed memories, possibly even identifying what is worth keeping and what to let go of.
During sleep, your mind analyzes collections of memories, helping you discover hidden relations between seemingly random pieces of information, and helps you find the meaning in what you have learned.
It’s been discovered that you need a minimum of six hours of sleep to see an improvement in your performance over the 24 hours following a learning session.
Memories are created by altering the strengths of connections among hundreds, thousands or perhaps even millions of neurons, making certain patterns of activity more likely to recur. These patterns of activity, when reactivated, lead to the recall of a memory—whether that memory is where you left your car keys or something you’re trying to memorize.
These changes in synaptic strength are thought to arise from a molecular process known as long-term potentiation, which strengthens the connections between pairs of neurons that fire at the same time. Thus, cells that fire together wire together, locking the pattern in place for future recall.
During sleep, your brain reactivates the patterns of neural activity that it performed during the day, thus strengthening your memories by long-term potentiation.
As this unconscious rehearsing strengthens memory, something more complex is happening as well—your brain may be selectively rehearsing the more difficult aspects of a task. It seems your brain needs time to process or “rehearse” new information, connecting the dots, so to speak—and sleep provides the maximum benefit.
As exciting new findings about sleep come in more and more rapidly, it becomes more and more clear that your brain is anything but inactive during sleep.
It is now clear that sleep can consolidate memories by enhancing and stabilizing them, and by finding patterns within studied material even when you don’t know that patterns might be there. It’s also clear that skimping on sleep can interfere with crucial cognitive processes. Miss a night of sleep, and the day’s memories might be compromised.
You sleep through one-third of your life, yet why you have to sleep is one of the most important unanswered mysteries of life. What is known is that humans are the only animals that continually push the limits of sleep -- and try to function without enough of it.
Scientific research is getting closer to solving the riddle of the purpose of sleep, however, and the article above offers up some really fascinating insights. In addition to their findings of just how sleep enhances your memories and helps you “practice” and improve particularly difficult skills, other sleep researchers from across the United States have discovered that:
- You can die from sleep deprivation, just like you can die from being deprived of food.
- A single night of sleeping only four to six hours can impact your ability to think clearly the next day.
- Good sleepers and poor sleepers experience about the same number of daily minor stressful events, but good sleepers are less disturbed by them. Poor sleepers experience both their minor and major life events as being more negative than do those who sleep well.
- Sleep deprivation can cause changes in your brain activity similar to those experienced by people with psychiatric disorders.
- Sleep deprivation puts your body into a pre-diabetic state, and makes you feel hungry, even if you’ve already eaten.
- Interrupted sleep can significantly.weaken your immune system
- Tumors grow two to three times faster in laboratory animals with severe sleep dysfunctions.
Is Your Biological Clock Set For the Right Time?
Your body depends on your biological clock (circadian rhythm) to steadily regulate your sleep/wake cycles. When this process gets thrown off balance – which is, unfortunately, very easy to do -- it can wreak havoc on your health.
For instance, all of the following can confuse your body and make it think you should be awake when you should be sleeping, or vice versa:
- Staying up late
- Working the night shift
- Turning on a light in the middle of the night
- Using a night light
- Switching time zones (jet lag)
- Eating in the middle of the night or too close to bedtime
Your body’s internal clocks (you actually have many, in your brain, lungs, liver, heart and even your skeletal muscles) influence so many things -- from your heart rate to body temperature and hormone production -- that when they’re disrupted, a cascade of negative health effects can occur.
For instance, too little sleep can:
1. Make you fat: People who sleep less than seven hours a night tend to have a higher body mass index (BMI) than people who sleep more. This could be because sleep deprivation alters metabolism. Leptin (the hormone that signals satiety) falls, while ghrelin (which signals hunger) rises, which boosts your appetite.
2. Harm your brain: Lack of sleep may cause your brain to stop producing new cells.
3. Increase your risk of cancer: How well you sleep can seriously alter the balance of hormones in your body. This can then disrupt your sleep/wake cycle, also called your circadian rhythm. A disrupted circadian rhythm may influence cancer progression through shifts in hormones like melatonin, which your brain makes during sleep.
4. Increase your risk of diabetes: Too little sleep may reduce levels of leptin, possibly causing you to gain weight and then develop diabetes.
5. Accelerate aging: Regularly catching only a few hours of sleep can hinder metabolism and hormone production in a way that is similar to the effects of aging.
Studies have also linked sleep deprivation to heart disease, high blood pressure, and stroke. And it’s during sleep that your body does most of its repairs, so not getting enough of it can impair your immune system, leaving you less able to fight off diseases of all kinds.
Despite all of this, in today’s society the ability to get just four or five hours of sleep a night is touted like a badge of honor. Unfortunately, you may think that you can function on just a little bit of sleep, but you cannot fool your body. All of the caffeine in the world cannot make up for the sleep you missed.
How Much Sleep Do You Need?
Generally speaking, adults need to get between six and eight hours of sleep a night. But there are definitely exceptions. Some people can, in fact, function well on as few as five hours a night, while others need up to 10. However there is some suggestion that sleeping more than 8 hours may actually cause problems similar to not enough sleep.
Oftentimes you will need more sleep during times of illness or emotional stress, or during the winter months. And pregnant women often need several hours more sleep than usual during their first three months of pregnancy.
A good rule of thumb to follow is that if you feel tired when you wake up, you probably aren’t getting enough sleep. Another clue is if you find yourself frequently yawning throughout the day. Most of us have set times that we need to wake up in the morning, so getting more sleep, for most of us, means going to bed earlier.
Personally, I usually sleep between six and seven hours a night, but sometimes as little as four. However, there are some major caveats here. I do not use an alarm clock, and sleep in a pitch dark room that is dark even at noon. So I wake up naturally once I am rested.
I have come to realize that if you aren’t jumping out of bed feeling rested, filled with joy, passion and enthusiasm for all the day has to offer you, you may need to do some serious life reflection.
Optimal Wellness Includes Sleeping Well
There is no better example of optimal wellness than to be in harmony with your deepest function… sleep.
The first step is to value sleep as one of your most precious resources for health and happiness. If you do that, you can figure out all the other things that would help you to sleep really well, and you’ll be better able to make health conscious choices during the day.
If you have trouble sleeping – whether it’s trouble falling asleep or waking repeatedly -- take advantage of some of the practical solutions I’ve outlined in my 33 Secrets to a Good Night's Sleep.
Also consider whether there may be some chronic emotional challenges such as anxiety or even depression that is impairing your sleep. I recommend using the Emotional Freedom Techniques (EFT) if you’re suffering with disturbed sleep as it effectively addresses emotional reasons for insomnia. See Using EFT for Insomnia