There are people who never dream

Question to the brain

Dr. Michael Schredl, sleep researcher at the Central Institute for Mental Health in Mannheim:

I have been dealing with dream content for many years and have analyzed over 5000 dreams. In principle, it is so that in dreams we deal with the things that we have perceived during the day and that occupy us during the day as well as with things that we have stored in memory for a long time.

But that's only one side of the coin. Because we can also dream much more than what we know. This is backed up by many studies. Just as in the waking state, we can create new things in dreams with our imagination. To dream that we are suddenly in Tokyo, even though we have never been to Tokyo and have not yet seen a film about Tokyo, is child's play. The monster in the dream doesn't have to be the monster we saw in the cinema. It can be a monster that we recreate in dreams. It is almost a trait of the dream that it can be innovative.

The dream mainly takes things from memory, but always tinkers new things together. We once analyzed a long series of dreams about pain. For example, one participant reported a dream in which he was hit in the stomach by a bullet - which was extremely painful for him. Of course, he had never seen that before.

But one cannot say that one dream is based only on reality and the other only on fantasy. The creation of new combinations of experiences or of completely new things is very common. I would say: the basis is almost always the experience of waking reality, the fantasy is the icing on the cake.

Students mainly dream of university and friends. Children dream a lot about animals and fears. Older people often dream of their problems, for example with their health. Then there is the broad field of nightmares: there are recurring motifs such as falling dreams or dreams of persecution in which one cannot move. I once analyzed dreams about my partner. This occurs in 20 percent of dreams and is a common topic.

In this light, dream contents are inevitably culture-dependent. A German dreams differently than a Chinese or a Yanomami Indian. Unfortunately, there are only a few cross-cultural studies. But it is clear that there are universal dream topics. The basic theme is universal, the design depends on the culture. The persecution dream, for example, is everywhere. But in one culture you are more likely to be haunted by a monster you know from a movie, in the other by a dangerous animal that you come across more often.

We also dream of the Internet and Facebook. All modern media appear in dreams. However, we have found that cognitive activities - sitting at the computer, reading, calculating, writing - are underrepresented in the dream. This means that the dreaming brain prefers to deal with social interactions than, for example, with the boring lecture material. But the more important the lecture material gets, for example before an important exam, the sooner it pushes itself into the dream.

Recorded by Klaus Wilhelm