Thank god just a dream! Anyone who experiences anxious situations while sleeping is often happy when consciousness returns to reality. Bad dreams are definitely good news: they help us cope with negative emotions in everyday life, as researchers report. Accordingly, fear-inducing situations in the dream function as training for similar experiences in the waking state. Prepared in this way, we can evidently better control our feelings of fear and face threats and dangers more carefully.
When we sleep, we immerse ourselves in a strange world. In this dreamland we can experience the most bizarre things, but also go through surprisingly realistic situations. Often these experiences have already faded when we wake up and are soon beyond our memory. But sometimes they keep us busy for days. Researchers have always been fascinated by this phenomenon: How do dreams come about? And what biological function do they fulfill? One theory suggests that dreams help us cope with the waking life. Accordingly, we process problems from everyday life and deal with our emotions.
Fear in sleep
Virginie Sterpenich from the University of Geneva and her colleagues have dedicated themselves to the function of a particularly strong feeling: fear. They wanted to know: What happens when we experience fear in a dream and how does this affect how we deal with this emotion in the waking state? To find out, the scientists looked at 18 test subjects using electroencephalography (EEG) while sleeping. In doing so, they repeatedly woke up the test subjects and asked them about their dream experiences. In combination with the measured brain activity, the participants’ responses provided clues as to which areas of the thinking organ are active during bad dreams. “We identified two brain regions that play a role in the fear experienced in dreams: the insula and the cingulate cortex,” reports Sterpenich’s colleague Lampros Perogamvros.
The exciting thing about it: Both areas of the brain are activated even in fearful situations in everyday life. The neurons in the insula are responsible for evaluating emotions and fire automatically as soon as someone feels fear. The cingulate cortex, in turn, prepares us for the adequate response in such situations. He controls how we behave in the face of danger and threat. “For the first time, we are showing that when we experience fear in sleep and when we are awake, similar regions are activated,” says Perogamvros. But what is the connection between fear in these two so different worlds?
Training for the waking state
In a second experiment, looking for an answer, the researchers asked 89 test persons to keep a dream diary for a week. Every morning, right after waking up, the participants noted whether they could remember a nightly dream and, if so, what emotions it was shaped by. At the end of the test week, the scientists then examined the test subjects using functional magnetic resonance imaging (fMRI). They showed them both neutral and fear-inducing images – for example of a robbery. The striking result: Those who had experienced fear more often and for longer in their dreams reacted much less strongly to these negative images.
“Both the insula and the cingulate cortex as well as the amygdala were less active in this case,” reports Sterpenich. In addition, it was shown that the middle prefrontal cortex was activated more strongly at the same time – this brain region can inhibit the amygdala in fearful situations and thus ensure that we are not paralyzed or overwhelmed by this feeling. According to the researchers, this shows that there is a pronounced connection between the fear in dreams and that in reality. The emotion experienced while sleeping serves as a kind of exercise – it helps us to react better in fearful situations while we are awake. “Dreams could be a training for future reactions and prepare us to face real dangers and threats,” states Perogamvros.
How do nightmares work?
This finding may lead to new approaches for the therapy of anxiety disorders, as the scientists explain. But the healing power of anxious dreams could also have a limit – when it comes to strong nightmares. “We believe: If a certain threshold of fear is exceeded in the dream, it loses its function as an emotional regulator,” says Perogamvros. The researchers want to investigate in future studies whether this is true. She is also interested in the function of positive feelings in dreams: How do they affect our behavior in the waking state? There is still a lot to find out about the influence of our dreams.
Source: Virginie Sterpenich (University of Geneva, Switzerland) et al., Human Brain Mapping, doi: 10.1002 / hbm.24843