People Communicate With Facial Expressions in Sleep, Says Study: What We Know

A recent study has found that we can communicate even in complete state of rest - sleep.

A new study in the Paris Brain Institute has suggested that individuals can communicate during their sleep. 

A state of sleep is considered to be a state of complete rest for both our mind and body. A recent research published in the Nature Journal (Neuroscience), showed that people were able to respond to verbal stimuli when sleeping through their facial expressions. 

The Big Point: People without any considerable sleeping disorder were able to make sense of verbal information transmitted to them in a human voice, showed the study. People responded to these words, through smiling and frowning while they were asleep. 

This was prevalent in all stages of sleep – when you're falling sleep, are in deep sleep – though it was intermittent – it has been reported to happen in windows and not throughout the period of sleep. 

Professor Lionel Naccache, a neurologist at Pitié-Salpêtrière AP-HP hospital and researcher in neuroscience, explained in a press release:

“Although it seems familiar to us because we indulge in it every night, sleep is a very complex phenomenon. Our research has taught us that waking and sleeping are not stable states: they are both a mosaic of conscious moments… and moments that do not seem to be.”

Why Does it Matter? Scientists are contemplating the possibility of developing a standardised mechanism of interacting with individuals in their sleep to understand better how our mental activity changes while we are asleep. 

“Most participants, whether narcoleptic or not, were able to respond correctly to verbal stimuli while remaining asleep. These events were certainly more frequent during lucid dream episodes, characterized by a high level of consciousness; but we observed them occasionally in both groups, during all phases of sleep,” specifies Professor Isabelle Arnulf Sorbonne Université, Institut du Cerveau — Paris Brain Institute.

Brain mechanisms during sleep may be associated with sleeping disorders such as sleep walking, hallucinations, sleep paralysis, etc. 

“Unregulated, they can be associated with disorders such as sleepwalking, sleep paralysis, hallucinations, the feeling of not sleeping at night, or on the contrary of being asleep with your eyes open,” specifies Professor Isabelle Arnulf , head of the sleep pathologies department at the Pitié-Salpêtrière AP-HP Hospital.

What Was Done? The research was conducted by selecting 22 participants without sleeping disorders and 27 participants with narcolepsy – which is a sleeping disorder in which simply put a person does not have control over their sleep, they are unable to repress sleep. 

The latter group is also more likely to lucid dream – be aware that they are dreaming and at times control the dream, which made them ideal candidates for the study. 

The groups were then instructed to smile or frown, while asleep if they heard any verbal stimuli. The facial expressions were used to understand if the participants were able to distinguish between ‘words’ and ‘pseudowords’.