You are here: Home Q&A Questions and Answers What is the difference between sleep-talking and talking while awake?

Questions and Answers

Vragen en Antwoorden Nederlands Fragen und Antworten Deutsch

Is there something you have always wanted to know about language? We might have an answer! On this page we answer questions about various aspects of language asked by people outside of the language researcher community.

What is the difference between sleep-talking and talking while awake?

People do all kinds of things while sleeping. They move around, mumble, laugh, and some also sometimes whisper or produce speech while asleep. Sleep-talking (or: somniloquy) happens at all ages and may occur during all phases of sleep. But what exactly is the difference between sleep-talking and normal everyday speech?

7.09 sleep

Image: Paul Sapiano

Sleep-talk contains more speech errors than everyday speech. For instance, sleep-talkers can have trouble retrieving a word (word finding problems) or switch individual sounds when producing a word (for example beatag instead of teabag). While this of course also occurs during normal speech, it happens more frequently during sleep. Sleep-talk sometimes resembles speech produced by aphasic patients. In addition, sleep-talk resembles the speech that is sometimes produced by patients suffering from schizophrenia, in that there is less of a connection between utterances, which may lead to relatively incoherent discourse. Finally, sleep-talk may be less well articulated (mumbling) than everyday speech and contain incomprehensible words or newly invented words (neologisms).

However, perhaps the most striking thing is the similarity between sleep-talk and speech produced when awake. People produce full sentences while sleeping and the grammatical structure of their utterance is often perfectly correct. There are even some anecdotal reports describing people that would be more eloquent and creative during sleep compared to being awake, for instance when speaking a second language.

Sleep-talking does not necessarily indicate a psychological disorder or psychopathology. However, it may co-occur with sleep-disorder syndromes such as somnambulism (walking around while sleeping). Also, people that have encountered a traumatic event (such as soldiers who have fought in a war) are found to talk more in their sleep than non-traumatized control subjects. Besides such environmental factors, it has been found that there is also a genetic component to sleep-talking. If your parents are regular sleep-talkers, there is a higher chance that you are a sleep-talker yourself as well.

In conclusion, in linguistic terms sleep-talk differs less from talking while being awake than one may suspect. The main difference boils down to the popular belief that we have less control over what we say during sleep than during the day. Or as The Romantics put it in their 1984 hit: "I hear the secrets that you keep; When you're talking in your sleep; and I know that I’m right, cause I hear it in the night". Whether this is really the case has not been researched scientifically.

 Written by David Peeters and Roel M. Willems

Further reading:

Arkin, A. (1981). Sleep talking. Psychology and psychophysiology. Hillsdale, NJ: Lawrence Erlbaum Associates.

About MPI

This is the MPI

The Max Planck Institute for Psycholinguistics is an institute of the German Max Planck Society. Our mission is to undertake basic research into the psychological,social and biological foundations of language. The goal is to understand how our minds and brains process language, how language interacts with other aspects of mind, and how we can learn languages of quite different types.

The institute is situated on the campus of the Radboud University. We participate in the Donders Institute for Brain, Cognition and Behaviour, and have particularly close ties to that institute's Centre for Cognitive Neuroimaging. We also participate in the Centre for Language Studies. A joint graduate school, the IMPRS in Language Sciences, links the Donders Institute, the CLS and the MPI.


Questions and Answers

whiet question mark on MPG green 124pt, stroke 2pt

This project was coordinated by:

Katrien Segaert 
Katerina Kucera
Judith Holler

Sean Roberts
Agnieszka Konopka
Gwilym Lockwood
Elma Hilbrink
Joost Rommers
Mark Dingemanse
Connie de Vos