My name is Sanjay Singh, and I'm the director of the Neurological Institute here at CHI Health.
What Happens in the Brain as we Sleep and Why is Sleep Important?
It's kind of a mystery, because until a few years ago we really had no idea why we sleep. Also, we sleep for one third of our life span. We did know that if you kept animals awake and did not let them sleep, they did not live. Now in the last three to five years we've learned a little bit more. So, we've learned that during sleep, your brain actually washes away all the toxins from your brain. That is why, if there are sleep disturbances, there lots of neurological problems that can occur like a stroke or dementia and other things. Also your memory gets consolidated during sleep.
What are the Stages of Sleep? What is REM Sleep?
When you’re sleeping, your brain is still very active, and there are four stages of sleep your brain goes through. There are stage 1 and stage 2, which is considered light sleep, stage 3 which is deep sleep, and then stage 4, which is called REM sleep. REM, or rapid eye movement, sleep is the most interesting. During this stage, the eyes are jiggling under your eyelids, and that is generally the dream phase of your sleep.
How Much Sleep Do we Need and What Happens if We Don’t Get it?
Every adult needs about seven to nine hours of sleep. What happens if you don't sleep enough? We do know from studies that you can then be at high risk for high blood pressure, diabetes heart disease, neurological diseases, psychiatric illnesses, and obesity. So it is very important that we get enough sleep.
Does Everyone Dream? What Happens When we Dream?
We absolutely have no idea why someone would dream. But, it has to bestow some biological advantage, otherwise it wouldn’t be happening. The other question I often get is, “Does everyone dream?” Yes, everyone does dream. Every single one of you had three to four dreams last night, but you will not remember them all. The reason for that is because as you move out of REM sleep, you forget your dreams.
The other interesting thing that happens when you’re dreaming, is that your entire body, your arms, your legs, become paralyzed. This is actually important so that you don't act out your dreams! This phenomenon is fascinating by itself in that every night, every human being is being paralyzed three or four times, and then you regain all your power and strength back as you get out of that phase of sleep. In a few people who may not be paralyzed, they actually have a disorder, called REM behavior disorder, in which they do act out their dreams. Some people can punch holes in walls or hurt their spouses if they are sleeping with them. So it is sort of an unfortunate but fascinating disorder that happens to some people, though very rare.
How do You Study Dreaming Further, and What Are You Hoping to Find Out?
The question still remains of, “Why do we dream?” That is a topic of research that we have undertaken here. One way we research this is we are letting people sleep and monitor their brain waves. After they’ve fallen asleep, we wake them up during their first dream phase the first night, second dream phase the second night, third dream phase the third night to find out what they dreamt about. On the fourth night, we try to see if we can influence their dreams. Interestingly, most theories out there now say that you cannot influence dreams, and that when people are dreaming they're completely cut off from the environment. BUT, we think that may not be true. For example, some of us may have had that experience where you get up in the morning you're not sure whether this is happening in your dream or in real life. That right there tells us that your brains not totally cut off from the environment.
How do we test dream influence? When we have people sleep, we can tell by their brain waves that they're dreaming. We can then ring a bell, and if the person (when they wake up) says something like, “I was walking down the street and suddenly I heard church bells ringing,” they've internalized what we did. Similarly, if we sprinkle a few droplets of water on them and they say, “I was walking down the street and suddenly it started raining.” So, we are trying to study dreams in a way it has never been studied before. We aim to find out why we dream, what do we dream about, and can we influence dreams. Also, a long-term goal in neurology is to see if dreams change in those who have certain diseases and disorders; and by changing your dreams can we reverse those diseases and disorders? It’s a new way of looking at health and disease.