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Why do we talk in our sleep? © iStock

Why do we talk in our sleep?

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Talking in your sleep, or somniloquy is mostly harmless, unless you say something that would make your mother blush.

Asked by: Catherine Flind, Cirencester


When we are sleeping, there is a brain mechanism that stops the neural activity associated with dreaming from triggering speech or body movements. But this system isn’t perfect, and sometimes signals can get through. This can lead to mumbling and groaning and sometimes even proper speech (and sleep walking).

The content of sleep talking can be complex and is usually grammatically correct. It may be influenced by recent events in the sleeper’s life, but can be strange and nonsensical. Sleep talking is usually benign, although stress and other psychological problems can increase the likelihood of it occurring.


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Dr Christian Jarrett is a cognitive neuroscientist, science writer and author. He is the Deputy Editor of Psyche, the sister magazine to Aeon that illuminates the human condition through psychology, philosophy and the arts. Jarrett also created the British Psychological Society's Research Digest blog and was the first ever staff journalist on the Society's magazine, The Psychologist. He is author of Great Myths of The Brain and Be Who You Want: Unlocking the Science of Personality Change.


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