How Sleep Creates Better Brain Function

By Dr Cynthia Horner

Part one of three:

We know that lack of sleep makes us old, fat, sick and stupid! We also know that sleep creates better brain function.During sleep our brains replay and process what we learned while awake. Sleep improves and refines thinking, learning, memory, reasoning, mood, dexterity and coordination.


Why We Sleepimages

Our bodies are wired to survive and reproduce. From a view of survival of ancient man, sleeping could have been a hazard. While sleeping, man was more vulnerable to attacks from wild beast or other tribes. So why are we designed to fall asleep after 16 or so hours of wakefulness? When you are asleep your brain is not resting at all, in about 80% of our time asleep our brains are more active than when we are awake. During sleep our brains replay and process what we learned while awake. Much like defragging your computer while offline, our brains organize experiences and also decide if they should be put into long term memory or discarded. All this happens while we shut off the world around us and stop the flow of further input. When we are sleeping; from the outside it may look like nothing is happening but celluarly we are quite busy.

Research has found people sleep deprived begin to lose their ability to use the nutrition from food they’ve eaten. Their ability to make insulin and use glucose for energy diminishes, this causes the body’s stress hormones to rise as do the cravings for glucose (sugar). This accelerates aging.


What Makes Us Fall Asleep?

You can’t help but fall asleep and wake up. It is caused by a fine balance of chemicals and hormones that play a seesaw game of when I’m up, you’re down but when I’ve been up for a while I go down and let you go up. Theses cycles are called our circadian rhythms. Approximately every 16 hours your sleep chemicals go up and your arousal chemicals go down, you get sleepy and fall asleep. After approximately 8 hours your arousal chemicals go up and sleep chemicals go down and you wake. These chemicals are at a fairly equal balance mid-day, neither one up over the other. This lack of dominance of either set of chemicals may be the reason some people like to nap mid-day, their arousal chemicals are not up enough to keep them feeling totally alert.

The time this seesaw game takes place can differ in different people. Many find they are ‘wired’ to wake late in the morning and enjoy high creativity and alertness in the evening, their counterparts can’t stay awake past 10:00 but rise early and ready to go. Both of these patterns are hard wired into the DNA in about 30% of the population according to John Medina a Bio-engineer and author of Brain Rules.  It is normal for these sleep patterns to change slightly as we age.

Are We Too Busy To Sleep?

More Americans are complaining of not getting a good night sleep, but are often over caffeinated, over medicated, over wired, over scheduled,  over worked, over stressed and over weight. Any and all of the above are a recipe for a poor nights sleep. About 50 % of all Americans suffer from some form of sleep difficulty, either in getting to sleep or staying asleep. The American work ethic is telling us to drive to the top at all cost. Productivity is king, rest is considered laziness. This thinking has filtered down to our schools affecting the health of our children. Getting 8 hours or more of sleep for high school students is rare and often considered a luxury.

A Canadian study of fifth graders (published in the journal of Pediatric Obesity September 2012) showed that loss of sleep increased the odds of being overweight by 28%. On the other hand children getting 9 to 10 hours of sleep every night enjoyed physical activity more and made better diet choices. Canadian researchers found children with electronic devices (TVs, computers, video games, DVD players, and cell phones) in the bedroom were far more likely to be sleeping less than 8 hours and more likely to be overweight.


Look forward to part two-  sleep postures.


What my patients have taught me “Don’t confuse downtime with sleep. Give yourself the gift of enough deep, peaceful sleep.”