One side of your brain could give you nightmares

The researchers believe they have identified a pattern of brain activity that predicts the anger felt during dreams.

If they are right, it could help explain the neural basis of the emotional content of nightmares, which are associated with mental and sleep disorders such as anxiety, depression, and insomnia.

As humans experience both waking and dreaming emotions, research on the brain mechanisms underlying the emotional component of dreams has been limited.

In the recent study, Pilleriin Sikka and colleagues at the University of Turku in Finland, the University of Skövde in Sweden and the University of Cambridge in the United Kingdom discovered a common emotional mechanism between the two states of consciousness .

The researchers obtained electroencephalographic recordings of 17 healthy people on two separate nights in a sleep laboratory.

Once the participants reached REM sleep – the point where dreams are most alive – they were awakened and invited to describe their dreams and evaluate their emotions.

It was found that those with higher alpha cerebral activity in the right frontal cortex, compared to the left, both during the evening vigil and during REM sleep, felt more anger in their dreams.

This neuronal signature – called frontal alpha asymmetry (FAA) – has been associated with anger and self-regulation during wakefulness.

"We show that individuals with more FAA (ie, greater right alpha power) during REM sleep, and during the evening vigil, experience more anger in their dreams," the researchers write. an article published in the newspaper JNeurosci.

"The FAA can thus reflect the ability to regulate emotions not only in the waking state, but also in the dream state."

The study had limitations – including the fact that it was done under laboratory conditions – but the researchers suggest that their findings "support theories that dream is a realistic simulation of life on awakening" .

They emphasize, however, that this study alone does not allow us to say: if the particular neuronal activation accompanying dream anger supports a certain function, for example experiencing threatening situations or negative affective states in order to to do better with them in waking life.