Scientists Discover Neurological Link Explaining Nightmares

A pro-democracy protester sleeps on a concrete road divider on a street outside the Hong Kong Government Complex on October 5, 2014 in Hong Kong, Hong Kong.
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Scientists believe they have discovered the reasons why people have nightmares and angry dreams, and it has to do with an imbalance between two regions of the brain.

In a new study published in the Journal for Neuroscience, the scientists explained how they identified a pattern of brain activity that is linked with anger experienced while awake and during dreams.

The research may help scientists unlock the mysteries behind why people have bad dreams as it points to a neurological foundation for the cause of the emotional content in nightmares. Understanding this link may also help researchers understand other mental and sleep disorders.

Scientists know very little about the emotions humans experience while they are dreaming. The study, however, conducted by Pilleriin Sikka and others at universities in Finland, Sweden, and the U.K., revealed a shared emotional pattern between individuals while they were sleeping and while they were awake.

More specifically, the researchers discovered an effect called “frontal alpha asymmetry,” or FAA, in which a particular type of brain activity is higher in one side of the brain than the other.

Experts studied electroencephalography results from 17 healthy individuals — seven men and 10 women — over the course of two nights in a sleep laboratory. The individuals were awakened after they had been in rapid eye movement sleep for five minutes and were asked to describe their dreams and identify their emotions. REM is the time in which dreams are the most vivid.

Research showed that participants who experienced less brain activity in their right frontal cortex experienced more anger in their dreams during REM sleep.

Researchers also discovered that individuals who displayed greater FAA in the right frontal cortex during REM sleep also did so while they were awake. This same neurological activity has also been linked to anger during wakefulness.

“It has been shown that expressing anger is related to relatively greater left [frontal activity], whereas controlling anger is related to relatively greater right frontal activity,” Sikka said, the Daily Mail reported.

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“Participants experienced more anger in dreams than during the evening wakefulness, whereas the evening and morning anger ratings did not differ,” he added.

The report stated that FAA may “reflect the ability to regulate emotions not only in the waking but also in the dreaming state.”

These results suggest that FAA may also indicate some sort of universal indicator of emotion regulation.

While the research was limited, experts are hoping that their findings will help scientists determine if dreaming simulates waking life.