Participants of the study were 232 volunteers who had been talking in my sleep more than once a week. While they slept in the laboratory, video cameras filmed their behavior, and special equipment recorded the performance of the body, including brain activity.

Altogether, there were 3349 words. The most common word was "No", it sounded 5.3% of cases. All the denial in a different form was recorded in 21.4% of cases and in 90% they were addressed to someone.

Participants in the study said more than one hundred complicated sentences, 20% of them it was addressed to someone: "I don't know. You don't say anything. Do something, so we can have some fun. I don't know. Conceive Stephanie of Monaco? Get out to see you don't want!".

Only 12 samples contained a polite speech, while the curses were written more than 60. "The complexity of the question suggests that the sleeping brain remains capable of complex, high-level activity, although articulatory system is partially weakened, — the researchers conclude. Negation, questions, and profanity prevail during conversations, which points to frequent conflicts in the mind during sleep".

The language component of sleep is a rich source of information about what is happening at this time, the processes in the brain, the researchers note. They believe that the analysis of speech sleeping people can tell a lot about the brain.