For many people, the occasional nightmare and bad dream is a fact of life.

Research suggests that between 55 and 85% of people will have the odd disruption to their sleep here and there, in the form of a nightmare or a bad dream. Until recently, though, very little has been known about why we get these kinds of sleep interruptions might occur. Though it is well known that nightmares occur during slow wave sleep, or the deepest part of your non-REM night cycle, other than that they have been a mystery.

A new study from the University of Geneva has sought to put nightmares under the microscope, though, with some fascinating results. The study, which used high-density electroencephalography (EEG) to examine brain activity during participants sleep cycles, found that nightmares triggers a certain part of a person’s brain. The study also found that, upon waking, those who had suffered a bad dream were better equipped to deal with fears and scary situations than those who did not.

Dream interpretation: how our nightmares prepare us to face our real-life fears