Study says that many people will curse in their sleep, every now and then I'll hear my husband saying something but not always understandable, I might say a word or two in a nightmare....but neither of us have cursed out loud in our sleep. Do you talk or curse in your sleep? medicalxpress.com/news/2018-01-reveals-talkers.html
A team of researchers with members from several institutions in France has conducted a study regarding sleep talking and has found that most sleep talking is not only negative in nature, but involves a large amount of swearing. In their paper published in the journal Sleep, the group describes their study, which involved watching and recording hundreds of volunteers as they slept.
Objectives
Speech is a complex function in humans, but the linguistic characteristics of sleep talking are unknown. We analyzed sleep-associated speech in adults, mostly (92%) during parasomnias.
Methods
The utterances recorded during night-time video-polysomnography were analyzed for number of words, propositions and speech episodes, frequency, gaps and pauses (denoting turn-taking in the conversation), lemmatization, verbosity, negative/imperative/interrogative tone, first/second person, politeness, and abuse.
Results
Two hundred thirty-two subjects (aged 49.5 ± 20 years old; 41% women; 129 with rapid eye movement [REM] sleep behavior disorder and 87 with sleepwalking/sleep terrors, 15 healthy subjects, and 1 patient with sleep apnea speaking in non-REM sleep) uttered 883 speech episodes, containing 59% nonverbal utterance (mumbles, shouts, whispers, and laughs) and 3349 understandable words.
The most frequent word was "No": negations represented 21.4% of clauses (more in non-REM sleep). Interrogations were found in 26% of speech episodes (more in non-REM sleep), and subordinate clauses were found in 12.9% of speech episodes. As many as 9.7% of clauses contained profanities (more in non-REM sleep).
Verbal abuse lasted longer in REM sleep and was mostly directed toward insulting or condemning someone, whereas swearing predominated in non-REM sleep. Men sleep-talked more than women and used a higher proportion of profanities. Apparent turn-taking in the conversation respected the usual language gaps.
Conclusions
Sleep talking parallels awake talking for syntax, semantics, and turn-taking in conversation, suggesting that the sleeping brain can function at a high level. Language during sleep is mostly a familiar, tensed conversation with inaudible others, suggestive of conflicts.