Under the microscope: Motor running as deep sleepers take a walk

I hope my husband will forgive me for airing his dirty laundry in public, but he’s a sleepwalker. And not just a sleepwalker. He can hold an entire (though not entirely rational) conversation in his sleep. He’s even been known to eat while asleep.

As far as I know I’ve never been sleepwalking.

But somewhere around one out of every three people have.

To understand sleepwalking you need to know a bit about sleep. And it turns out sleep is more complicated than you might think. 

People have two types of sleep: rapid eye movement (REM) sleep, and non-REM sleep. REM sleep gets its name from what our eyes do in this phase – they move quickly side to side under our eyelids. Even people who are blind have these eye movements.

Although our eyes are busy, the rest of our muscles are paralysed when we’re in REM sleep. This is also when we’re most likely to dream.

We only spend about 20% of our night in REM sleep. The rest is in non-REM sleep, which also has different stages. Stage 1 is when you’re just drowsing and are easily awakened. Stage 2 is a light sleep, and stage 3 is a deep sleep.

When we fall asleep we start off in stage 1, then go to stage 2, stage 3, then into REM sleep. After a short time in REM sleep you then move back to non-REM stage 2, and go back through the cycle again.

The whole thing takes about an hour and a half, so we have multiple sleep cycles each night.

Sleep on its own is pretty interesting. But it’s even more interesting when people stop following these regular cycles and start sleepwalking instead.

Sleep on its own is pretty interesting. But it’s even more interesting when people stop following these regular cycles and start sleepwalking instead.

Sleepwalking happens during the deep sleep phase of non-REM sleep. Usually in this phase our brains produce a neurotransmitter that shuts down the part of the brain that controls our motor functions.

You might be dreaming that you’re running around, but really the most you’re doing is twitching a bit. In people who sleepwalk it seems that the brain doesn’t produce enough of this neurotransmitter. So the motor cortex of the brain can still function, and people can walk around, drive a car, and even in couple of famous cases, kill someone.

It’s not just my husband who’s a sleepwalker. We’ve caught our son wondering about on the odd occasion too.

There have been a few research studies suggesting that there could be a genetic basis to sleepwalking. So if you’re a sleepwalker there’s a good chance that your kids could be too.

If you’re already susceptible to sleepwalking then being really tired, stressed or even taking some medications can trigger episodes.

The good news is that, contrary to popular belief, you won’t actually do any harm by waking a sleepwalker. Sure they may be a bit startled and disoriented, but you won’t give them a heart attack or damage their brain. But from my experience it’s far more entertaining to just sit back and see what they’ll get up to next.

This story Motor running as deep sleepers take a walk first appeared on The Armidale Express.