We’ve all had bad dreams – you know, the ones where you go through a break-up, are being chased by a goat (just us?), or are late for a job interview.
On the face of it, they seem pretty pointless by the time you’ve woken up and realised there’s nothing to worry about. But new research suggests your bad dreams might serve a purpose in real life (IRL), too.
Scientists from Geneva analysed people’s brains while they were dreaming, and identified which areas were activated when they experienced fear. Once the individuals woke up, the areas of the brain responsible for controlling emotions responded to scary situations more effectively, they found, meaning dreams could actually help us react better to frightening situations in real life.
The same can’t necessarily be said for the terrifying nightmares, which jolt you out of your sleep, however.
What happened in the study?
Scientists placed several electrodes on participants’ skulls to measure brain activity during sleep. “We were particularly interested in fear: what areas of our brain are activated when we’re having bad dreams?” said Lampros Perogamvros, a researcher in the Sleep and Cognition Laboratory at the University of Geneva.
Each time the participants were woken up, they had to answer a series of questions, such as: Did you dream? And, if so, did you feel scared? By doing this, scientists identified two brain regions associated with fear experienced during dreams: the insula and the cingulate cortex.
The insula evaluates emotions when we’re awake and is “automatically activated” when someone feels afraid. The cingulate cortex plays a role in preparing motor and behavioural reactions in the event of a threat.
The researchers then investigated a possible link between the fear experienced during a dream and the emotions experienced when awake. They gave a dream diary to 89 participants for a week. Every day, the subjects noted down whether they remembered their dreams and identified emotions they felt.
At the end of the week, they were placed in a magnetic resonance imaging (MRI) machine where they were shown images of distressing situations, as well as neutral images. The aim was 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.
The research showed that the longer someone had felt fear in their dreams, the less the insula and cingulate cortex were activated when they looked at the negative pictures.
“Dreams may be considered as a real training for our future reactions and may potentially prepare us to face real life dangers,” said Perogamvros, who said the findings might pave the way for new dream-based therapeutic methods for combating anxiety disorders.
What about nightmares?
Unlike bad dreams – where the level of fear is moderate – nightmares are characterised by an excessive level of fear that disrupts sleep and has a negative impact on the individual once awake.
“We believe that if a certain threshold of fear is exceeded in a dream, it loses its beneficial role as an emotional regulator,” said Perogamvros.
A 2014 study by the University of Montreal analysed the narratives of nearly 10,000 dreams and discovered that physical aggression was the most frequently reported theme in nightmares, with death, health concerns and threats also being common. Bad dreams tended to be about interpersonal conflicts, they found.
What do others studies say?
There hasn’t been much research into the benefits of bad dreams, despite many studies looking into stressful dreams and nightmares in general.
In 2014, however, scientists in Paris found that anxiety in dreams “could play a useful role”. Researchers analysed a large group of students taking an entrance exam for medical school – looking to find a possible link between their dreams the night before and their results afterwards. Two-thirds dreamed about the exam, with 78% of these dreams being negative. Scientists found those who dreamed of the exam were more likely to perform better. “These results suggest that the negative anticipation of a stressful event in dreams is common and that this episodic simulation provides a cognitive gain,” the authors wrote.
There’s also evidence that having extremely vivid dreams could benefit your brain – but “vivid” could be used to describe good, or bad, dreams. The 2016 study in mice found that rapid eye movement (REM) sleep is correlated with forming long-lasting memories. “We were able to prove for the first time that REM sleep is indeed critical for normal spatial memory formation in mice,” the authors wrote.