Our bodies need rest, but it’s the brain that needs sleep. What happens in the brain makes the difference between resting and sleeping. Merely resting can slow the heart rate and respiration, and decrease our adrenalin level. However, it’s the diminishing brain activity that causes us to go to sleep. But even in sleep, the brain seems to need some stimulation, so that we all have dreams, even if we can’t remember them.
A recent study of Japanese men has shown that working long hours without sufficient rest triples the chances of having a heart attack. It’s our brain that suffers most when we’re deprived of sleep. In sleep deprivation experiments there’s little change in blood pressure, heart rate and reflexes. However, people who are forced to stay awake find that by the second or third day, they experience memory loss and hallucinations. When deprived of sleep, the brain presents us with delusions.
Paradoxically, it’s the brain that keeps us awake. Humans are unique in voluntarily spending more time awake than asleep. Our highly developed brains are curious and sociable, and unlike other living creatures, capable of boredom. With too much idling, a sensible dog or cat simply goes to sleep. But our brains are greedy for stimulation, and they quickly drive us to find something new to pique our interest.
So next time you feel sleepy, give your brain a break. And if you can doze safely, let it happen.