By definition, sleep talking is a disorder that sufferers don’t know they have. When they find out, fear quickly follows: Did I say something embarrassing? Reveal my inner desires? My deepest, darkest secret? New research from the Sorbonne reveals that our sleep speech isn’t usually that saucy. But it can reveal clues into our dreams – and unravel mysteries about the sleeping brain.

In the first study of its kind, Dr. Isabelle Arnulf and her team at the European Sleep Research Laboratories found that we follow the same speech patterns while we sleep as we do when we’re awake. We use proper syntax, mind our grammar, and pause for imaginary respondents to participate in the conversation. We are, however, three times more negative and 800 times more likely to curse as we slumber.

What We Say in Our Sleep

You probably won’t disclose personal secrets, but you may allude to things or people you encountered during the day. According to Dr. Deirdre Barrett, Harvard professor and “The Committee of Sleep” author, sleep talking is usually provocative. But it’s mostly fanciful, fictional material, so we shouldn’t take sleep talking too seriously. Dr. Arnulf told us that it’s often difficult to understand sleep speech anyway: “The mean number of understandable words uttered per night is 15 in women and 22 in men.”

It varies by subject, but sleep speech tends to be “negative, interrogative, and brief.” Several researchers have found that sleep talk is mostly heated conversations with an unidentified “you.” Nearly 10 percent of the sleep talk in Dr. Arnulf’s study contained profanities, and “no” was the most frequently spoken term. Men were both more likely to talk in their sleep and more likely to curse.

Dr. Arnulf’s team has come up with multiple possible reasons we’re so aggressive as we snooze. She hypothesizes that it’s probably because sleep talk is related to our dreams, which tend to be more negative than positive. According to Arnulf, it could also be that some parts of our frontal lobe aren’t connected during sleep or that sleep talk only represents the last, but most emotive part of a longer dream sequence.

Why We Talk in Our Sleep

Sleep talking has long been linked to anxiety. Dr. Nerina Ramlakhan, sleep therapist and author of “Fast Asleep Wide Awake,” told us that we talk in our sleep to express unresolved conflict and stress. She says that those who keep their feelings bottled up during the day are more likely to spill in their sleep. She’s also found that stimulants like technology, caffeine, and alcohol activate our nervous system and lead to greater incidences of sleep talking. Eating well, reducing exposure to such stimulants, and keeping a journal can help you kick the habit. Getting enough sleep is also key, as sleep deprived individuals tend to sleep talk more.

There are, however, natural predispositions for sleep talking as well. Dr. Barrett told us that sleep talking is more common in children, with between 22-60 percent of the young population speaking in their sleep at least occasionally. In the Sorbonne study, Dr. Arnulf found that people who talked in their sleep as children were more likely to talk in their sleep as adults.

Sleep talking may also be hereditary, as you’re more likely to talk in your sleep if you come from a family of sleep talkers. Dr. Barrett pointed us to a Finnish study of twins, which highlighted heritability for both sleepwalking and sleep talking. It turns out you’re also more likely to talk in your sleep if you walk in your sleep.

When Talking in Sleep is a Problem

Sleep talking is usually rare and short-lived. Most cases are innocent and don’t require treatment. Sleep talking is actually a bigger problem to partners than the talkers themselves. Dr. Barrett suggests that those with sleep talking partners invest in earplugs or move to a separate bed.

However, if you start sleep talking after a traumatic experience, you may want to consult a professional. And if you’re suffering from excessive daytime fatigue on top of sleep talking, it could indicate something more serious. As a rule of thumb, you should seek a specialist’s help if you’re sleep talking several nights a month or if you’re exhibiting other disruptive sleep behaviors, like shouting or kicking, too.

The Power of the Sleeping Brain

Professor Arnulf’s study found that the sleeping brain uses the same networks as the waking one, indicating that sleep is not the “passive, isolated state” people once believed it to be. In fact, our brains function at an extremely high level as we sleep, activating both the frontal and temporal lobes. Perhaps most impressive, our sleeping brains seem able to hallucinate conversations in real time.

The Future of Sleep Speech

This research is widely believed to be the largest sleep talking study ever conducted. Arnulf believes the difficulty of capturing sleep-talking data could be why more scientists aren’t going further. Her team recorded more than 15,000 sleeping people over five years to gather just 232 recordings of coherent sleep talk. She encourages her peers to continue pushing the subject though. Sleep talking studies offer a foundation for solving some of the remaining mysteries about sleep.

Plus, it can be fun. Dr. Barrett’s research has shown that a sleep talker can arouse their bed partner into conversation, creating whacky dialogues. In one recording, someone said, “You’re talking in your sleep,” and the other responded, “No, you’re talking in your sleep!” In truth, they both were. Very meta — and entertaining.

If you’re curious to hear what you say in bed, try downloading a sleep talk recorder app. You just may discover what you’ve been dreaming about. At the very least, you’ll get a funny story.


Sleep Healthy, Sleep Restored

What is Microsleep?
Lose While You Snooze: Sleep & Weight Loss