The Purpose of Dreams Might Be to Prepare Us to Face Our Fears
Anyone who has had a scary dream has likely wondered what the purpose of such dreams is. What is the point of our minds terrorizing us by night? A new study may be able to shed light on that, concluding that scary dreams prepare us to deal with real-life threats.
“Dreams may be considered as real training for our future reactions and may potentially prepare us to face real-life dangers,” Dr. Lampros Perogamvros, a psychiatrist and researcher in the Sleep and Cognition Laboratory in the department of basic neurosciences at the University of Geneva, said in a statement.
After mapping the dreaming brains of 18 subjects using high-density electroencephalography (EEG), which measures brain activity via electrodes placed on the skull, the researchers identified two brain regions associated with fear during consciousness; these — specifically, the insula and the cingulate cortex — also appeared active during dreams.
They then broadened their investigation to 89 people, who were given a dream diary for a week in which to record whether they remembered the dream they had had during the night and what emotion it evoked.
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After seven days, these individuals underwent magnetic resonance imaging (MRI) while viewing a series of negative images depicting assaults or stressful situations and a series of neutral images; this allowed them to observe which brain areas associated with fear response became active during wakefulness and whether a recent scary dream had any effect on them. Their results were published in the journal Human Brain Mapping.
“We found that the longer a someone had felt fear in their dreams, the less the insula, cingulate and amygdala [the brain region that flips on the fight-or-flight response] were activated when the same person looked at the negative pictures,” Virginie Sterpenich, a researcher in the department of basic neurosciences at the University, said in a statement. The researchers also found activity in the medial prefrontal cortex, the part of the brain that can inhibit the amygdala’s panic-switch in the event of a threat, increased in proportion to the number of recent scary dreams a subject had experienced.
In other words, the brains of people who recently had scary dreams were less overwhelmed in the face of a real-life threat while conscious. This supports a common theory that the purpose of scary dreams is to prepare us to react better to threats in waking life.
Researchers caution that not all scary dreams are created equal, however, nightmares — dreams characterized by extreme levels of fear — often disrupt sleep and linger with an individual long after they wake. Their future work will examine nightmares more closely; they suspect they will not find the same benefits from them as from mildly scary dreams.
“We believe that if a certain threshold of fear is exceeded in a dream, it loses its beneficial role as an emotional regulator,” Dr. Perogamvros said.