Nightmares are never a good time for anyone, but new research indicates that those horrific dreams actually serve a purpose. A team of researchers from the United States and Switzerland conducted a dream study that identified the parts of the brain that are active when you are having a nightmare. When participants woke up, those same activated areas – the parts of the brain that regulate emotions – responded to scary situations in real life much more effectively.
The research team concluded that this proves that the purpose of nightmares is to help the brain prepare for anxiety-provoking situations in the real world. They believe that this opens the door to a variety of different dream-based therapies for treating anxiety disorders.
Neuroscientists have made dreams a major area of study in recent years, specifically the parts of the brain that are responsible for actually falling asleep. Researchers have only recently identified the parts of the brain that are responsible for forming dreams. Most interestingly, only certain parts of the brain are activated depending on the type of dream you’re having. We’ve known for a fact that sleep reboots the brain for a while now, but research on nightmares is still in its infancy.
“We were particularly interested in fear: what areas of our brain are activated when we’re having bad dreams?” said researcher Lampros Perogamvros, who works at the University of Geneva and University Hospitals of Geneva, in a release.
How was the study conducted?
For this study, 18 participants were fitted with EEG electrodes – designed to measure brain activity – and were woken up multiple times throughout the night. Every time they woke up, researchers peppered them with questions like “Did you dream?” and “If so, did you feel fear?”
“By analyzing the brain activity based on participants’ responses, we identified two brain regions implicated in the induction of fear experienced during the dream: the insula and the cingulate cortex”, Perogamvros told us.
The insula is the part of the brain that is responsible for regulating emotions when we’re awake, automatically activating as soon as you feel fear. The cingulate cortex is the portion of the brain that helps control your reactions during a threatening situation.
“For the first time, we’ve identified the neural correlates of fear when we dream and have observed that similar regions are activated when experiencing fear in both sleep and wakeful states,” Perogamvros continued.
Once the researchers were able to determine the parts of the brain that were activated while having nightmares, they next wanted to determine how this affects our waking lives. They gave a dream diary to an additional 89 participants who were instructed to write down the emotions they felt while sleeping every day for a full week. After seven days, the participants were placed in an MRI machine while being shown a series of images.
How researchers determined the relationship between nightmares and waking anxiety
“We showed each participant emotionally-negative images, such as assaults or distressful situations, as well as neutral images, to see which areas of the brain were more active for fear, and whether the activated area changed depending on the emotions experienced in the dreams over the previous week,” said Virginie Sterpenich, a researcher in the Department of Basic Neurosciences at the University of Geneva.
The researchers focused specifically on the areas of the brain that are associated with emotions – the insula, medial prefontal cortex, amygdala, and cingulate cortex.
“We found that the longer a someone had felt fear in their dreams, the less the insula, cingulate and amygdala were activated when the same person looked at the negative pictures,” Sterpenich added. “In addition, the activity in the medial prefrontal cortex, which is known to inhibit the amygdala in the event of fear, increased in proportion to the number of frightening dreams!”
The beneficial effects of nightmares on waking anxiety do have a limit, however. If you’re completely terrified while dreaming, you lose most of the anxiety-reducing effects due to the risk of sleep disruption and stress upon waking up. This holds true even you managed to get enough deep sleep, which has been shown to reduce anxiety.
“We believe that if a certain threshold of fear is exceeded in a dream, it loses its beneficial role as an emotional regulator,” Perogamvros stated in the conclusion.