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Most people wake up from a bad dream feeling relieved it wasn’t real. But what if those unsettling dreams are actually doing your brain a favor? Scientists are beginning to uncover a fascinating possibility: frightening dreams may act like a mental training program, helping your brain rehearse how to deal with danger before it happens in real life.
Key Takeaways
- Bad dreams may have a biological purpose. They could help the brain process emotions and prepare for real-life threats.
- The same fear centers activate in dreams and waking life. The insula and cingulate cortex respond during both dream fear and real-world stress.
- Moderate fear in dreams may improve emotional resilience. People who experienced more fear in dreams showed calmer brain responses to negative stimuli while awake.
Why Your Brain Might Actually Need Bad Dreams
Ancient Greeks and Romans believed dreams predicted the future. Sigmund Freud thought they expressed repressed conflicts or desires and could help people unravel the reasons for mental illness.
I take a dim view of both theories, but a new study now shows bad dreams do help us out in a completely different way.
Scientists today speculate they serve an important biological purpose: Dreams in general - good and bad - might help the brain dump excess data, consolidate important information, and keep us alert to danger.
Dreams Are a Training Ground for the Future
An interesting idea recently emerged from neuroscience that the experience of fear in dreams is linked to how we'll later respond to a real threat when we're wide awake.Lampros Perogamvros, a sleep researcher at the University of Geneva, explored this idea, hoping to discover whether bad dreams serve any useful function.
Dr. Perogamvros and his research associates designed two studies:
In the first, researchers placed 256 high-density electroencephalograph (EEG) electrodes on the heads of 18 volunteers before they went to sleep. This new, sophisticated type of EEG acquires much more data than the standard EEG of 18 to 24 sensors, providing a detailed three-dimensional electrical image of the brain.
They woke each participant several times during the night and asked whether they experienced fear in their dreams. From their responses, the scientists identified two brain regions implicated in fear, the insula and the cingulate cortex.
Same Fear Centers Activated When Asleep and Awake
The insula is a deeply buried area of the brain that researchers began studying in the last 25 years. It seems to be activated across a wide range of thoughts and behaviors during wakefulness, including fear.The cingulate cortex plays an important role in emotion, including the preparation of both motor and behavioral responses to a threat.
Dr. Perogamvros commented on their findings, "For the first time, we've identified the neural correlates of fear [i.e. what happens physically in the brain] when we dream and have observed that similar regions are activated when experiencing fear in both sleep and wakeful states."
In the second study, researchers asked 89 participants to write down any dreams they could recall upon waking and to identify all emotions they felt, including fear.
At the end of one week, researchers gave each participant an MRI brain scan. The scientists looked in particular at areas involved with emotions, not just the insula and cingulate cortex but also the amygdala and medial prefrontal cortex.
Bad Dreams Help You Better React to Stressful Situations
What happened next is described by another member of the team, Dr. Virginie Sterpenich. "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."We found," Dr. Sterpenich continued, "that the longer 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.
"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!"
What this research demonstrates is a strong link between the emotions we feel in both our sleep and waking states. This reinforces the theory that the brain generates our frightening dreams to train itself to better react to fearful situations in our daily lives.
Or as Dr. Perogamvros puts it, "Dreams may be considered as a real training for our future reactions and may potentially prepare us to face real-life dangers."
However, according to the researchers, this only applies to moderate amounts of fear. If fear becomes excessive, it loses its beneficial role.
So, we should look forward to bad dreams - but not nightmares.
Meet
The Expert:
The Expert:
Carl Lowe has decades of experience writing about health and nutrition for many publications, including Prevention Magazine and Self Magazine (where he served as the food and nutrition editor). He has authored and edited over 10 books about natural health, nutrition, and other subjects. He edited The Columbia University College of Physicians and Surgeons Complete Home Medical Guide and was the nutrition editor for a Time-Life book series on health and nutrition. As a musician, he played viola with the Yale Symphony and bass with the Tommy Dorsey Band, and he has appeared on national TV.