eli5: What happens in the brain during sleepwalking and related parasomnias?


I’ve heard stories of people performing some pretty complicated tasks while asleep, like cooking and eating full meals, driving a car, beating the shit out of their bedmate, having sex, and even bypassing attempts to prevent any of the above. How does a sleeping person get so dang clever and coordinated?

In: 7

The same way you can complete complex tasks in your sleep. When you fall asleep, your brain normally flips a few switches: it shuts off your perception of the outside world (somewhat), it starts generating imagery and sound of its own, it alters your consciousness so that you participate in this dream world as if it were real, it messes with your ability to form long-term memories, and it paralyzes you so that when you try and move your arm, you’re only moving your dream arm.

With sleepwalkers, these switches don’t get flipped off correctly. They still end up in an altered state of consciousness, but they’re not correctly cut off from the rest of the real world, so they’ll still have some ability to move around and perceive and interact with some things around them. They just incorporate it all into their dream.

Doctors actually don’t fully understand the causes of sleepwalking.