A few nights ago I had a bad dream (I won’t bore you with the details) and woke feeling fearful and disoriented. It was a crappy start to my day and I felt a bit off for the next few hours. We’ve all been there. But maybe bad dreams have a beneficial purpose.
Research from the University of Geneva suggests that bad dreams serve a beneficial purpose by helping us react better to scary situations when awake.
In the study, over multiple nights volunteers slept hooked up EEGs and also were surveyed about their dreams. Then their brains were scanned by an MRI. Based on the EEG, survey, and MRI, the researchers determined that the same areas of the brain are stimulated by bad dreams and fearful situations when awake.
Next, the researchers showed volunteers emotionally negative images while hooked up to a functional MRI machine and found an inverse correlation between the intensity and frequency of bad dreams and the stimulation of the fear parts of the brain. In other words, the volunteers who had more bad dreams had less fearful or negative emotions in response to the troubling images.
The study authors posit that our brains simulate frightening situations while dreaming in order to better react to them once we’re awake. “Dreams may be considered as a real training for our future reactions and may potentially prepare us to face real-life dangers,” said one of the researchers.
One important note: this study’s conclusion applies to bad dreams and not to nightmares which they defined as a bad dream “characterized by an excessive level of fear that disrupts sleep and has a negative impact on the individual once awake.” The disruption of sleep and excessive fear produced by nightmares may not provide the benefits of more run-of-the-mill bad dreams: “We believe that if a certain threshold of fear is exceeded in a dream, it loses its beneficial role as an emotional regulator.”