The research reported by “dailymail.co.uk” and partly published in the journal “Human Brain Mapping” is based on the sleep behaviour of 18 test persons as well as on the questioning of another 89 persons about their dreams.
The brain activities of the sleepers were monitored with electrodes. If the scientists registered special rashes, the test persons were awakened and asked about their dreams. The most important point was whether the study participants had just felt anxiety during sleep, i.e. had a nightmare. The second study was based on a similar principle, although a dream diary was evaluated that the participants had kept themselves.
Terrible images always stimulate certain brain regions
In the second phase of the experiment, the scientists confronted the waking subjects with frightening images. This involved determining which areas of the brain react to the negative stimuli and in what way.
The result was clear. For all those who had previously experienced bad dreams, the brain reacted quickly and very efficiently to the frightening images in the waking state. It also turned out that the same regions of the brain were addressed.
The explanation is: “The insula releases our fear reaction in times of danger, while the cingulierte cortex controls it”.
Study: The brain learns from nightmares
Of particular interest to the researchers was the fact that the brain’s reactions were apparently based on a kind of pre-training from dreams. Virginie Sterpenich, neuroscientist at the University of Geneva, points out that the longer a subject experienced fear in his dreams, the smaller and more controlled the brain’s reactions to the negative images in these areas were.
In another part of the brain, which is said to be responsible for the suppression of anxiety, activity has increased. From this it can be concluded that nightmares can contribute to later coping with stress and dangerous situations.
The brain is prepared, it can react appropriately to the danger.
Bad nightmares burden us very much
At the same time, however, the scientists make it clear that this positive effect has limits. If nightmares occur, for example after traumatic experiences that lead to insomnia and inner stress, a red line is crossed.
Lampros Perogamvros, one of the main authors of the study, says: “We believe that when a certain threshold of fear is exceeded in a dream, it loses its positive role as an emotional regulator.