If you’ve ever wondered why people’s arms and legs suddenly twitch as they drift off to sleep, our resident psychologist Tom Stafford has the answer. As we drift off to sleep, sudden twitches escape our brains and cause our arms and legs to twitch. Some people are startled by them, others are embarrassed.
I, on the other hand, am fascinated by these twitches, known as hypnic twitches. No one knows exactly what causes them, but to me they represent the side effects of a hidden battle for control in the brain that takes place every night on the threshold between wakefulness and dreaming. Normally, we are paralyzed in sleep.
Even during the most vivid dreams, our muscles remain relaxed and calm, showing little of our inner agitation. Events in the outside world are usually ignored: while it’s not recommended to do so, experiments have shown that even if you sleep with your eyes open and someone flashes a light in your face, it’s unlikely to affect your dreams.
Why Do I Jerk Awake Right As I’m Falling Asleep? But the door between the dreamer and the outside world is not completely closed. Two kinds of motion escape the dreaming brain, and each has a different story to tell.
